get_pages

The timeline below displays how wordpress function get_pages has changed across different WordPress versions. If a version is not listed, refer to the next available version below.

WordPress Version: 3.2

/**
 * Retrieves an array of pages (or hierarchical post type items).
 *
 * @since 1.5.0
 * @since 6.3.0 Use WP_Query internally.
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of. Note: The value
 *                                      of `$hierarchical` has no bearing on whether `$child_of` returns
 *                                      hierarchical results. Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. If false in conjunction with
 *                                      `$child_of` also being false, both arguments will be disregarded.
 *                                      Default true.
 *     @type int[]        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type int[]        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. Default -1, or no restriction.
 *     @type string|int[] $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string|array $post_status  A comma-separated list or array of post statuses to include.
 *                                      Default 'publish'.
 * }
 * @return WP_Post[]|false Array of pages (or hierarchical post type items). Boolean false if the
 *                         specified post type is not hierarchical or the specified status is not
 *                         supported by the post type.
 */
function get_pages($args = array())
{
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $parsed_args = wp_parse_args($args, $defaults);
    $number = (int) $parsed_args['number'];
    $offset = (int) $parsed_args['offset'];
    $child_of = (int) $parsed_args['child_of'];
    $hierarchical = $parsed_args['hierarchical'];
    $exclude = $parsed_args['exclude'];
    $meta_key = $parsed_args['meta_key'];
    $meta_value = $parsed_args['meta_value'];
    $parent = $parsed_args['parent'];
    $post_status = $parsed_args['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($parsed_args['post_type'], $hierarchical_post_types, true)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    $query_args = array('orderby' => 'post_title', 'order' => 'ASC', 'post__not_in' => wp_parse_id_list($exclude), 'meta_key' => $meta_key, 'meta_value' => $meta_value, 'posts_per_page' => -1, 'offset' => $offset, 'post_type' => $parsed_args['post_type'], 'post_status' => $post_status, 'update_post_term_cache' => false, 'update_post_meta_cache' => false, 'ignore_sticky_posts' => true, 'no_found_rows' => true);
    if (!empty($parsed_args['include'])) {
        $child_of = 0;
        // Ignore child_of, parent, exclude, meta_key, and meta_value params if using include.
        $parent = -1;
        unset($query_args['post__not_in'], $query_args['meta_key'], $query_args['meta_value']);
        $hierarchical = false;
        $query_args['post__in'] = wp_parse_id_list($parsed_args['include']);
    }
    if (!empty($parsed_args['authors'])) {
        $post_authors = wp_parse_list($parsed_args['authors']);
        if (!empty($post_authors)) {
            $query_args['author__in'] = array();
            foreach ($post_authors as $post_author) {
                // Do we have an author id or an author login?
                if (0 == (int) $post_author) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                $query_args['author__in'][] = (int) $post_author;
            }
        }
    }
    if (is_array($parent)) {
        $post_parent__in = array_map('absint', (array) $parent);
        if (!empty($post_parent__in)) {
            $query_args['post_parent__in'] = $post_parent__in;
        }
    } elseif ($parent >= 0) {
        $query_args['post_parent'] = $parent;
    }
    /*
     * Maintain backward compatibility for `sort_column` key.
     * Additionally to `WP_Query`, it has been supporting the `post_modified_gmt` field, so this logic will translate
     * it to `post_modified` which should result in the same order given the two dates in the fields match.
     */
    $orderby = wp_parse_list($parsed_args['sort_column']);
    $orderby = array_map(static function ($orderby_field) {
        $orderby_field = trim($orderby_field);
        if ('post_modified_gmt' === $orderby_field || 'modified_gmt' === $orderby_field) {
            $orderby_field = str_replace('_gmt', '', $orderby_field);
        }
        return $orderby_field;
    }, $orderby);
    if ($orderby) {
        $query_args['orderby'] = array_fill_keys($orderby, $parsed_args['sort_order']);
    }
    $order = $parsed_args['sort_order'];
    if ($order) {
        $query_args['order'] = $order;
    }
    if (!empty($number)) {
        $query_args['posts_per_page'] = $number;
    }
    /**
     * Filters query arguments passed to WP_Query in get_pages.
     *
     * @since 6.3.0
     *
     * @param array $query_args  Array of arguments passed to WP_Query.
     * @param array $parsed_args Array of get_pages() arguments.
     */
    $query_args = apply_filters('get_pages_query_args', $query_args, $parsed_args);
    $pages = new WP_Query();
    $pages = $pages->query($query_args);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($parsed_args['exclude_tree'])) {
        $exclude = wp_parse_id_list($parsed_args['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude, true)) {
                unset($pages[$i]);
            }
        }
    }
    /**
     * Filters the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param WP_Post[] $pages       Array of page objects.
     * @param array     $parsed_args Array of get_pages() arguments.
     */
    return apply_filters('get_pages', $pages, $parsed_args);
}

WordPress Version: 6.3

/**
 * Retrieves an array of pages (or hierarchical post type items).
 *
 * @since 1.5.0
 * @since 6.3.0 Use WP_Query internally.
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of. Note: The value
 *                                      of `$hierarchical` has no bearing on whether `$child_of` returns
 *                                      hierarchical results. Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. If false in conjunction with
 *                                      `$child_of` also being false, both arguments will be disregarded.
 *                                      Default true.
 *     @type int[]        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type int[]        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. Default -1, or no restriction.
 *     @type string|int[] $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string|array $post_status  A comma-separated list or array of post statuses to include.
 *                                      Default 'publish'.
 * }
 * @return WP_Post[]|false Array of pages (or hierarchical post type items). Boolean false if the
 *                         specified post type is not hierarchical or the specified status is not
 *                         supported by the post type.
 */
function get_pages($args = array())
{
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $parsed_args = wp_parse_args($args, $defaults);
    $number = (int) $parsed_args['number'];
    $offset = (int) $parsed_args['offset'];
    $child_of = (int) $parsed_args['child_of'];
    $hierarchical = $parsed_args['hierarchical'];
    $exclude = $parsed_args['exclude'];
    $meta_key = $parsed_args['meta_key'];
    $meta_value = $parsed_args['meta_value'];
    $parent = $parsed_args['parent'];
    $post_status = $parsed_args['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($parsed_args['post_type'], $hierarchical_post_types, true)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    $query_args = array('orderby' => 'post_title', 'order' => 'ASC', 'post__not_in' => wp_parse_id_list($exclude), 'meta_key' => $meta_key, 'meta_value' => $meta_value, 'posts_per_page' => -1, 'offset' => $offset, 'post_type' => $parsed_args['post_type'], 'post_status' => $post_status, 'update_post_term_cache' => false, 'update_post_meta_cache' => false, 'ignore_sticky_posts' => true, 'no_found_rows' => true);
    if (!empty($parsed_args['include'])) {
        $child_of = 0;
        // Ignore child_of, parent, exclude, meta_key, and meta_value params if using include.
        $parent = -1;
        unset($query_args['post__not_in'], $query_args['meta_key'], $query_args['meta_value']);
        $hierarchical = false;
        $query_args['post__in'] = wp_parse_id_list($parsed_args['include']);
    }
    if (!empty($parsed_args['authors'])) {
        $post_authors = wp_parse_list($parsed_args['authors']);
        if (!empty($post_authors)) {
            $query_args['author__in'] = array();
            foreach ($post_authors as $post_author) {
                // Do we have an author id or an author login?
                if (0 == (int) $post_author) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                $query_args['author__in'][] = (int) $post_author;
            }
        }
    }
    if (is_array($parent)) {
        $post_parent__in = array_map('absint', (array) $parent);
        if (!empty($post_parent__in)) {
            $query_args['post_parent__in'] = $post_parent__in;
        }
    } elseif ($parent >= 0) {
        $query_args['post_parent'] = $parent;
    }
    $orderby = wp_parse_list($parsed_args['sort_column']);
    $orderby = array_map('trim', $orderby);
    if ($orderby) {
        $query_args['orderby'] = array_fill_keys($orderby, $parsed_args['sort_order']);
    }
    $order = $parsed_args['sort_order'];
    if ($order) {
        $query_args['order'] = $order;
    }
    if (!empty($number)) {
        $query_args['posts_per_page'] = $number;
    }
    /**
     * Filters query arguments passed to WP_Query in get_pages.
     *
     * @since 6.3.0
     *
     * @param array $query_args  Array of arguments passed to WP_Query.
     * @param array $parsed_args Array of get_pages() arguments.
     */
    $query_args = apply_filters('get_pages_query_args', $query_args, $parsed_args);
    $query = new WP_Query($query_args);
    $pages = $query->get_posts();
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($parsed_args['exclude_tree'])) {
        $exclude = wp_parse_id_list($parsed_args['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude, true)) {
                unset($pages[$i]);
            }
        }
    }
    /**
     * Filters the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param WP_Post[] $pages       Array of page objects.
     * @param array     $parsed_args Array of get_pages() arguments.
     */
    return apply_filters('get_pages', $pages, $parsed_args);
}

WordPress Version: 6.1

/**
 * Retrieves an array of pages (or hierarchical post type items).
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 1.5.0
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of. Note: The value
 *                                      of `$hierarchical` has no bearing on whether `$child_of` returns
 *                                      hierarchical results. Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. If false in conjunction with
 *                                      `$child_of` also being false, both arguments will be disregarded.
 *                                      Default true.
 *     @type int[]        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type int[]        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. Default -1, or no restriction.
 *     @type string|int[] $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string|array $post_status  A comma-separated list or array of post statuses to include.
 *                                      Default 'publish'.
 * }
 * @return WP_Post[]|false Array of pages (or hierarchical post type items). Boolean false if the
 *                         specified post type is not hierarchical or the specified status is not
 *                         supported by the post type.
 */
function get_pages($args = array())
{
    global $wpdb;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $parsed_args = wp_parse_args($args, $defaults);
    $number = (int) $parsed_args['number'];
    $offset = (int) $parsed_args['offset'];
    $child_of = (int) $parsed_args['child_of'];
    $hierarchical = $parsed_args['hierarchical'];
    $exclude = $parsed_args['exclude'];
    $meta_key = $parsed_args['meta_key'];
    $meta_value = $parsed_args['meta_value'];
    $parent = $parsed_args['parent'];
    $post_status = $parsed_args['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($parsed_args['post_type'], $hierarchical_post_types, true)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key.
    $key = md5(serialize(wp_array_slice_assoc($parsed_args, array_keys($defaults))));
    $last_changed = wp_cache_get_last_changed('posts');
    $cache_key = "get_pages:{$key}:{$last_changed}";
    $cache = wp_cache_get($cache_key, 'posts');
    if (false !== $cache) {
        _prime_post_caches($cache, false, false);
        // Convert to WP_Post instances.
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $parsed_args);
        return $pages;
    }
    $inclusions = '';
    if (!empty($parsed_args['include'])) {
        $child_of = 0;
        // Ignore child_of, parent, exclude, meta_key, and meta_value params if using include.
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($parsed_args['include']);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($parsed_args['authors'])) {
        $post_authors = wp_parse_list($parsed_args['authors']);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                // Do we have an author id or an author login?
                if (0 == (int) $post_author) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' === $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' !== $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed.
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 === count($post_status)) {
        $where_post_type = $wpdb->prepare('post_type = %s AND post_status = %s', $parsed_args['post_type'], reset($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $parsed_args['post_type']);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $parsed_args['sort_column']) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys, true)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($parsed_args['sort_order']);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'), true)) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= ' ORDER BY ' . $sort_column . ' ' . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        wp_cache_set($cache_key, array(), 'posts');
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $parsed_args);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once.
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($parsed_args['exclude_tree'])) {
        $exclude = wp_parse_id_list($parsed_args['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude, true)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances.
    $pages = array_map('get_post', $pages);
    /**
     * Filters the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param WP_Post[] $pages       Array of page objects.
     * @param array     $parsed_args Array of get_pages() arguments.
     */
    return apply_filters('get_pages', $pages, $parsed_args);
}

WordPress Version: 5.8

/**
 * Retrieve an array of pages (or hierarchical post type items).
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 1.5.0
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of. Note: The value
 *                                      of `$hierarchical` has no bearing on whether `$child_of` returns
 *                                      hierarchical results. Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. If false in conjunction with
 *                                      `$child_of` also being false, both arguments will be disregarded.
 *                                      Default true.
 *     @type int[]        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type int[]        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. Default -1, or no restriction.
 *     @type string|int[] $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string|array $post_status  A comma-separated list or array of post statuses to include.
 *                                      Default 'publish'.
 * }
 * @return WP_Post[]|int[]|false Array of pages (or hierarchical post type items). Boolean false if the
 *                               specified post type is not hierarchical or the specified status is not
 *                               supported by the post type.
 */
function get_pages($args = array())
{
    global $wpdb;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $parsed_args = wp_parse_args($args, $defaults);
    $number = (int) $parsed_args['number'];
    $offset = (int) $parsed_args['offset'];
    $child_of = (int) $parsed_args['child_of'];
    $hierarchical = $parsed_args['hierarchical'];
    $exclude = $parsed_args['exclude'];
    $meta_key = $parsed_args['meta_key'];
    $meta_value = $parsed_args['meta_value'];
    $parent = $parsed_args['parent'];
    $post_status = $parsed_args['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($parsed_args['post_type'], $hierarchical_post_types, true)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key.
    $key = md5(serialize(wp_array_slice_assoc($parsed_args, array_keys($defaults))));
    $last_changed = wp_cache_get_last_changed('posts');
    $cache_key = "get_pages:{$key}:{$last_changed}";
    $cache = wp_cache_get($cache_key, 'posts');
    if (false !== $cache) {
        _prime_post_caches($cache, false, false);
        // Convert to WP_Post instances.
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $parsed_args);
        return $pages;
    }
    $inclusions = '';
    if (!empty($parsed_args['include'])) {
        $child_of = 0;
        // Ignore child_of, parent, exclude, meta_key, and meta_value params if using include.
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($parsed_args['include']);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($parsed_args['authors'])) {
        $post_authors = wp_parse_list($parsed_args['authors']);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                // Do we have an author id or an author login?
                if (0 == (int) $post_author) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' === $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' !== $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed.
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 === count($post_status)) {
        $where_post_type = $wpdb->prepare('post_type = %s AND post_status = %s', $parsed_args['post_type'], reset($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $parsed_args['post_type']);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $parsed_args['sort_column']) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys, true)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($parsed_args['sort_order']);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'), true)) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= ' ORDER BY ' . $sort_column . ' ' . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        wp_cache_set($cache_key, array(), 'posts');
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $parsed_args);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once.
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($parsed_args['exclude_tree'])) {
        $exclude = wp_parse_id_list($parsed_args['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude, true)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances.
    $pages = array_map('get_post', $pages);
    /**
     * Filters the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param WP_Post[] $pages       Array of page objects.
     * @param array     $parsed_args Array of get_pages() arguments.
     */
    return apply_filters('get_pages', $pages, $parsed_args);
}

WordPress Version: 5.7

/**
 * Retrieve an array of pages (or hierarchical post type items).
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 1.5.0
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of. Note: The value
 *                                      of `$hierarchical` has no bearing on whether `$child_of` returns
 *                                      hierarchical results. Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. If false in conjunction with
 *                                      `$child_of` also being false, both arguments will be disregarded.
 *                                      Default true.
 *     @type int[]        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type int[]        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. Default -1, or no restriction.
 *     @type string|int[] $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string|array $post_status  A comma-separated list or array of post statuses to include.
 *                                      Default 'publish'.
 * }
 * @return WP_Post[]|int[]|false Array of pages (or hierarchical post type items). Boolean false if the
 *                               specified post type is not hierarchical or the specified status is not
 *                               supported by the post type.
 */
function get_pages($args = array())
{
    global $wpdb;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $parsed_args = wp_parse_args($args, $defaults);
    $number = (int) $parsed_args['number'];
    $offset = (int) $parsed_args['offset'];
    $child_of = (int) $parsed_args['child_of'];
    $hierarchical = $parsed_args['hierarchical'];
    $exclude = $parsed_args['exclude'];
    $meta_key = $parsed_args['meta_key'];
    $meta_value = $parsed_args['meta_value'];
    $parent = $parsed_args['parent'];
    $post_status = $parsed_args['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($parsed_args['post_type'], $hierarchical_post_types, true)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key.
    $key = md5(serialize(wp_array_slice_assoc($parsed_args, array_keys($defaults))));
    $last_changed = wp_cache_get_last_changed('posts');
    $cache_key = "get_pages:{$key}:{$last_changed}";
    $cache = wp_cache_get($cache_key, 'posts');
    if (false !== $cache) {
        // Convert to WP_Post instances.
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $parsed_args);
        return $pages;
    }
    $inclusions = '';
    if (!empty($parsed_args['include'])) {
        $child_of = 0;
        // Ignore child_of, parent, exclude, meta_key, and meta_value params if using include.
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($parsed_args['include']);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($parsed_args['authors'])) {
        $post_authors = wp_parse_list($parsed_args['authors']);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                // Do we have an author id or an author login?
                if (0 == (int) $post_author) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' === $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' !== $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed.
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 === count($post_status)) {
        $where_post_type = $wpdb->prepare('post_type = %s AND post_status = %s', $parsed_args['post_type'], reset($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $parsed_args['post_type']);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $parsed_args['sort_column']) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys, true)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($parsed_args['sort_order']);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'), true)) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= ' ORDER BY ' . $sort_column . ' ' . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        wp_cache_set($cache_key, array(), 'posts');
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $parsed_args);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once.
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($parsed_args['exclude_tree'])) {
        $exclude = wp_parse_id_list($parsed_args['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude, true)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances.
    $pages = array_map('get_post', $pages);
    /**
     * Filters the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param WP_Post[] $pages       Array of page objects.
     * @param array     $parsed_args Array of get_pages() arguments.
     */
    return apply_filters('get_pages', $pages, $parsed_args);
}

WordPress Version: 5.6

/**
 * Retrieve an array of pages (or hierarchical post type items).
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 1.5.0
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of. Note: The value
 *                                      of `$hierarchical` has no bearing on whether `$child_of` returns
 *                                      hierarchical results. Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. If false in conjunction with
 *                                      `$child_of` also being false, both arguments will be disregarded.
 *                                      Default true.
 *     @type array        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type array        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. Default -1, or no restriction.
 *     @type string|array $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string|array $post_status  A comma-separated list or array of post statuses to include.
 *                                      Default 'publish'.
 * }
 * @return array|false Array of pages matching defaults or `$args`.
 */
function get_pages($args = array())
{
    global $wpdb;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $parsed_args = wp_parse_args($args, $defaults);
    $number = (int) $parsed_args['number'];
    $offset = (int) $parsed_args['offset'];
    $child_of = (int) $parsed_args['child_of'];
    $hierarchical = $parsed_args['hierarchical'];
    $exclude = $parsed_args['exclude'];
    $meta_key = $parsed_args['meta_key'];
    $meta_value = $parsed_args['meta_value'];
    $parent = $parsed_args['parent'];
    $post_status = $parsed_args['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($parsed_args['post_type'], $hierarchical_post_types, true)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key.
    $key = md5(serialize(wp_array_slice_assoc($parsed_args, array_keys($defaults))));
    $last_changed = wp_cache_get_last_changed('posts');
    $cache_key = "get_pages:{$key}:{$last_changed}";
    $cache = wp_cache_get($cache_key, 'posts');
    if (false !== $cache) {
        // Convert to WP_Post instances.
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $parsed_args);
        return $pages;
    }
    $inclusions = '';
    if (!empty($parsed_args['include'])) {
        $child_of = 0;
        // Ignore child_of, parent, exclude, meta_key, and meta_value params if using include.
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($parsed_args['include']);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($parsed_args['authors'])) {
        $post_authors = wp_parse_list($parsed_args['authors']);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                // Do we have an author id or an author login?
                if (0 == (int) $post_author) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' === $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' !== $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed.
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 === count($post_status)) {
        $where_post_type = $wpdb->prepare('post_type = %s AND post_status = %s', $parsed_args['post_type'], reset($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $parsed_args['post_type']);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $parsed_args['sort_column']) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys, true)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($parsed_args['sort_order']);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'), true)) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= ' ORDER BY ' . $sort_column . ' ' . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        wp_cache_set($cache_key, array(), 'posts');
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $parsed_args);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once.
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($parsed_args['exclude_tree'])) {
        $exclude = wp_parse_id_list($parsed_args['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude, true)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances.
    $pages = array_map('get_post', $pages);
    /**
     * Filters the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param WP_Post[] $pages       Array of page objects.
     * @param array     $parsed_args Array of get_pages() arguments.
     */
    return apply_filters('get_pages', $pages, $parsed_args);
}

WordPress Version: 5.5

/**
 * Retrieve a list of pages (or hierarchical post type items).
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 1.5.0
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of. Note: The value
 *                                      of `$hierarchical` has no bearing on whether `$child_of` returns
 *                                      hierarchical results. Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. If false in conjunction with
 *                                      `$child_of` also being false, both arguments will be disregarded.
 *                                      Default true.
 *     @type array        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type array        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. Default -1, or no restriction.
 *     @type string|array $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string|array $post_status  A comma-separated list or array of post statuses to include.
 *                                      Default 'publish'.
 * }
 * @return array|false List of pages matching defaults or `$args`.
 */
function get_pages($args = array())
{
    global $wpdb;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $parsed_args = wp_parse_args($args, $defaults);
    $number = (int) $parsed_args['number'];
    $offset = (int) $parsed_args['offset'];
    $child_of = (int) $parsed_args['child_of'];
    $hierarchical = $parsed_args['hierarchical'];
    $exclude = $parsed_args['exclude'];
    $meta_key = $parsed_args['meta_key'];
    $meta_value = $parsed_args['meta_value'];
    $parent = $parsed_args['parent'];
    $post_status = $parsed_args['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($parsed_args['post_type'], $hierarchical_post_types, true)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key.
    $key = md5(serialize(wp_array_slice_assoc($parsed_args, array_keys($defaults))));
    $last_changed = wp_cache_get_last_changed('posts');
    $cache_key = "get_pages:{$key}:{$last_changed}";
    $cache = wp_cache_get($cache_key, 'posts');
    if (false !== $cache) {
        // Convert to WP_Post instances.
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $parsed_args);
        return $pages;
    }
    $inclusions = '';
    if (!empty($parsed_args['include'])) {
        $child_of = 0;
        // Ignore child_of, parent, exclude, meta_key, and meta_value params if using include.
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($parsed_args['include']);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($parsed_args['authors'])) {
        $post_authors = wp_parse_list($parsed_args['authors']);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                // Do we have an author id or an author login?
                if (0 == intval($post_author)) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' === $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' !== $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed.
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 === count($post_status)) {
        $where_post_type = $wpdb->prepare('post_type = %s AND post_status = %s', $parsed_args['post_type'], reset($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $parsed_args['post_type']);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $parsed_args['sort_column']) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys, true)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($parsed_args['sort_order']);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'), true)) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= ' ORDER BY ' . $sort_column . ' ' . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        wp_cache_set($cache_key, array(), 'posts');
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $parsed_args);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once.
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($parsed_args['exclude_tree'])) {
        $exclude = wp_parse_id_list($parsed_args['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude, true)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances.
    $pages = array_map('get_post', $pages);
    /**
     * Filters the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param WP_Post[] $pages       Array of page objects.
     * @param array     $parsed_args Array of get_pages() arguments.
     */
    return apply_filters('get_pages', $pages, $parsed_args);
}

WordPress Version: 5.4

/**
 * Retrieve a list of pages (or hierarchical post type items).
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 1.5.0
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of. Note: The value
 *                                      of `$hierarchical` has no bearing on whether `$child_of` returns
 *                                      hierarchical results. Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. If false in conjunction with
 *                                      `$child_of` also being false, both arguments will be disregarded.
 *                                      Default true.
 *     @type array        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type array        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. Default -1, or no restriction.
 *     @type string|array $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string|array $post_status  A comma-separated list or array of post statuses to include.
 *                                      Default 'publish'.
 * }
 * @return array|false List of pages matching defaults or `$args`.
 */
function get_pages($args = array())
{
    global $wpdb;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $parsed_args = wp_parse_args($args, $defaults);
    $number = (int) $parsed_args['number'];
    $offset = (int) $parsed_args['offset'];
    $child_of = (int) $parsed_args['child_of'];
    $hierarchical = $parsed_args['hierarchical'];
    $exclude = $parsed_args['exclude'];
    $meta_key = $parsed_args['meta_key'];
    $meta_value = $parsed_args['meta_value'];
    $parent = $parsed_args['parent'];
    $post_status = $parsed_args['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($parsed_args['post_type'], $hierarchical_post_types)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key.
    $key = md5(serialize(wp_array_slice_assoc($parsed_args, array_keys($defaults))));
    $last_changed = wp_cache_get_last_changed('posts');
    $cache_key = "get_pages:{$key}:{$last_changed}";
    $cache = wp_cache_get($cache_key, 'posts');
    if (false !== $cache) {
        // Convert to WP_Post instances.
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $parsed_args);
        return $pages;
    }
    $inclusions = '';
    if (!empty($parsed_args['include'])) {
        $child_of = 0;
        // Ignore child_of, parent, exclude, meta_key, and meta_value params if using include.
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($parsed_args['include']);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($parsed_args['authors'])) {
        $post_authors = wp_parse_list($parsed_args['authors']);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                // Do we have an author id or an author login?
                if (0 == intval($post_author)) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' == $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' != $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed.
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 == count($post_status)) {
        $where_post_type = $wpdb->prepare('post_type = %s AND post_status = %s', $parsed_args['post_type'], reset($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $parsed_args['post_type']);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $parsed_args['sort_column']) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($parsed_args['sort_order']);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'))) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= ' ORDER BY ' . $sort_column . ' ' . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        wp_cache_set($cache_key, array(), 'posts');
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $parsed_args);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once.
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($parsed_args['exclude_tree'])) {
        $exclude = wp_parse_id_list($parsed_args['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances.
    $pages = array_map('get_post', $pages);
    /**
     * Filters the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param WP_Post[] $pages       Array of page objects.
     * @param array     $parsed_args Array of get_pages() arguments.
     */
    return apply_filters('get_pages', $pages, $parsed_args);
}

WordPress Version: 5.3

/**
 * Retrieve a list of pages (or hierarchical post type items).
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 1.5.0
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of. Note: The value
 *                                      of `$hierarchical` has no bearing on whether `$child_of` returns
 *                                      hierarchical results. Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. If false in conjunction with
 *                                      `$child_of` also being false, both arguments will be disregarded.
 *                                      Default true.
 *     @type array        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type array        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. Default -1, or no restriction.
 *     @type string|array $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string|array $post_status  A comma-separated list or array of post statuses to include.
 *                                      Default 'publish'.
 * }
 * @return array|false List of pages matching defaults or `$args`.
 */
function get_pages($args = array())
{
    global $wpdb;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $parsed_args = wp_parse_args($args, $defaults);
    $number = (int) $parsed_args['number'];
    $offset = (int) $parsed_args['offset'];
    $child_of = (int) $parsed_args['child_of'];
    $hierarchical = $parsed_args['hierarchical'];
    $exclude = $parsed_args['exclude'];
    $meta_key = $parsed_args['meta_key'];
    $meta_value = $parsed_args['meta_value'];
    $parent = $parsed_args['parent'];
    $post_status = $parsed_args['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($parsed_args['post_type'], $hierarchical_post_types)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key.
    $key = md5(serialize(wp_array_slice_assoc($parsed_args, array_keys($defaults))));
    $last_changed = wp_cache_get_last_changed('posts');
    $cache_key = "get_pages:{$key}:{$last_changed}";
    $cache = wp_cache_get($cache_key, 'posts');
    if (false !== $cache) {
        // Convert to WP_Post instances.
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $parsed_args);
        return $pages;
    }
    $inclusions = '';
    if (!empty($parsed_args['include'])) {
        $child_of = 0;
        //ignore child_of, parent, exclude, meta_key, and meta_value params if using include
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($parsed_args['include']);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($parsed_args['authors'])) {
        $post_authors = wp_parse_list($parsed_args['authors']);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                //Do we have an author id or an author login?
                if (0 == intval($post_author)) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' == $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' != $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 == count($post_status)) {
        $where_post_type = $wpdb->prepare('post_type = %s AND post_status = %s', $parsed_args['post_type'], reset($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $parsed_args['post_type']);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $parsed_args['sort_column']) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($parsed_args['sort_order']);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'))) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= ' ORDER BY ' . $sort_column . ' ' . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        wp_cache_set($cache_key, array(), 'posts');
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $parsed_args);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once.
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($parsed_args['exclude_tree'])) {
        $exclude = wp_parse_id_list($parsed_args['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances
    $pages = array_map('get_post', $pages);
    /**
     * Filters the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param array $pages List of pages to retrieve.
     * @param array $parsed_args     Array of get_pages() arguments.
     */
    return apply_filters('get_pages', $pages, $parsed_args);
}

WordPress Version: 5.1

/**
 * Retrieve a list of pages (or hierarchical post type items).
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 1.5.0
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of. Note: The value
 *                                      of `$hierarchical` has no bearing on whether `$child_of` returns
 *                                      hierarchical results. Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. If false in conjunction with
 *                                      `$child_of` also being false, both arguments will be disregarded.
 *                                      Default true.
 *     @type array        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type array        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. Default -1, or no restriction.
 *     @type string|array $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string|array $post_status  A comma-separated list or array of post statuses to include.
 *                                      Default 'publish'.
 * }
 * @return array|false List of pages matching defaults or `$args`.
 */
function get_pages($args = array())
{
    global $wpdb;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $r = wp_parse_args($args, $defaults);
    $number = (int) $r['number'];
    $offset = (int) $r['offset'];
    $child_of = (int) $r['child_of'];
    $hierarchical = $r['hierarchical'];
    $exclude = $r['exclude'];
    $meta_key = $r['meta_key'];
    $meta_value = $r['meta_value'];
    $parent = $r['parent'];
    $post_status = $r['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($r['post_type'], $hierarchical_post_types)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key.
    $key = md5(serialize(wp_array_slice_assoc($r, array_keys($defaults))));
    $last_changed = wp_cache_get_last_changed('posts');
    $cache_key = "get_pages:{$key}:{$last_changed}";
    $cache = wp_cache_get($cache_key, 'posts');
    if (false !== $cache) {
        // Convert to WP_Post instances.
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $r);
        return $pages;
    }
    $inclusions = '';
    if (!empty($r['include'])) {
        $child_of = 0;
        //ignore child_of, parent, exclude, meta_key, and meta_value params if using include
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($r['include']);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($r['authors'])) {
        $post_authors = wp_parse_list($r['authors']);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                //Do we have an author id or an author login?
                if (0 == intval($post_author)) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' == $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' != $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 == count($post_status)) {
        $where_post_type = $wpdb->prepare('post_type = %s AND post_status = %s', $r['post_type'], reset($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $r['post_type']);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $r['sort_column']) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($r['sort_order']);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'))) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= ' ORDER BY ' . $sort_column . ' ' . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        wp_cache_set($cache_key, array(), 'posts');
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $r);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once.
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($r['exclude_tree'])) {
        $exclude = wp_parse_id_list($r['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances
    $pages = array_map('get_post', $pages);
    /**
     * Filters the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param array $pages List of pages to retrieve.
     * @param array $r     Array of get_pages() arguments.
     */
    return apply_filters('get_pages', $pages, $r);
}

WordPress Version: 4.8

/**
 * Retrieve a list of pages (or hierarchical post type items).
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 1.5.0
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of. Note: The value
 *                                      of `$hierarchical` has no bearing on whether `$child_of` returns
 *                                      hierarchical results. Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. If false in conjunction with
 *                                      `$child_of` also being false, both arguments will be disregarded.
 *                                      Default true.
 *     @type array        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type array        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. Default -1, or no restriction.
 *     @type string|array $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string|array $post_status  A comma-separated list or array of post statuses to include.
 *                                      Default 'publish'.
 * }
 * @return array|false List of pages matching defaults or `$args`.
 */
function get_pages($args = array())
{
    global $wpdb;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $r = wp_parse_args($args, $defaults);
    $number = (int) $r['number'];
    $offset = (int) $r['offset'];
    $child_of = (int) $r['child_of'];
    $hierarchical = $r['hierarchical'];
    $exclude = $r['exclude'];
    $meta_key = $r['meta_key'];
    $meta_value = $r['meta_value'];
    $parent = $r['parent'];
    $post_status = $r['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($r['post_type'], $hierarchical_post_types)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key.
    $key = md5(serialize(wp_array_slice_assoc($r, array_keys($defaults))));
    $last_changed = wp_cache_get_last_changed('posts');
    $cache_key = "get_pages:{$key}:{$last_changed}";
    if ($cache = wp_cache_get($cache_key, 'posts')) {
        // Convert to WP_Post instances.
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $r);
        return $pages;
    }
    $inclusions = '';
    if (!empty($r['include'])) {
        $child_of = 0;
        //ignore child_of, parent, exclude, meta_key, and meta_value params if using include
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($r['include']);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($r['authors'])) {
        $post_authors = preg_split('/[\s,]+/', $r['authors']);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                //Do we have an author id or an author login?
                if (0 == intval($post_author)) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' == $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' != $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 == count($post_status)) {
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status = %s", $r['post_type'], reset($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $r['post_type']);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $r['sort_column']) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($r['sort_order']);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'))) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= " ORDER BY " . $sort_column . " " . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $r);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once.
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($r['exclude_tree'])) {
        $exclude = wp_parse_id_list($r['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances
    $pages = array_map('get_post', $pages);
    /**
     * Filters the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param array $pages List of pages to retrieve.
     * @param array $r     Array of get_pages() arguments.
     */
    return apply_filters('get_pages', $pages, $r);
}

WordPress Version: 4.7

/**
 * Retrieve a list of pages.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 1.5.0
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of. Note: The value
 *                                      of `$hierarchical` has no bearing on whether `$child_of` returns
 *                                      hierarchical results. Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. If false in conjunction with
 *                                      `$child_of` also being false, both arguments will be disregarded.
 *                                      Default true.
 *     @type array        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type array        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. Default -1, or no restriction.
 *     @type string|array $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string|array $post_status  A comma-separated list or array of post statuses to include.
 *                                      Default 'publish'.
 * }
 * @return array|false List of pages matching defaults or `$args`.
 */
function get_pages($args = array())
{
    global $wpdb;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $r = wp_parse_args($args, $defaults);
    $number = (int) $r['number'];
    $offset = (int) $r['offset'];
    $child_of = (int) $r['child_of'];
    $hierarchical = $r['hierarchical'];
    $exclude = $r['exclude'];
    $meta_key = $r['meta_key'];
    $meta_value = $r['meta_value'];
    $parent = $r['parent'];
    $post_status = $r['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($r['post_type'], $hierarchical_post_types)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key.
    $key = md5(serialize(wp_array_slice_assoc($r, array_keys($defaults))));
    $last_changed = wp_cache_get_last_changed('posts');
    $cache_key = "get_pages:{$key}:{$last_changed}";
    if ($cache = wp_cache_get($cache_key, 'posts')) {
        // Convert to WP_Post instances.
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $r);
        return $pages;
    }
    $inclusions = '';
    if (!empty($r['include'])) {
        $child_of = 0;
        //ignore child_of, parent, exclude, meta_key, and meta_value params if using include
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($r['include']);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($r['authors'])) {
        $post_authors = preg_split('/[\s,]+/', $r['authors']);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                //Do we have an author id or an author login?
                if (0 == intval($post_author)) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' == $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' != $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 == count($post_status)) {
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status = %s", $r['post_type'], reset($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $r['post_type']);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $r['sort_column']) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($r['sort_order']);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'))) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= " ORDER BY " . $sort_column . " " . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $r);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once.
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($r['exclude_tree'])) {
        $exclude = wp_parse_id_list($r['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances
    $pages = array_map('get_post', $pages);
    /**
     * Filters the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param array $pages List of pages to retrieve.
     * @param array $r     Array of get_pages() arguments.
     */
    return apply_filters('get_pages', $pages, $r);
}

WordPress Version: 4.6

/**
 * Retrieve a list of pages.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 1.5.0
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of. Note: The value
 *                                      of `$hierarchical` has no bearing on whether `$child_of` returns
 *                                      hierarchical results. Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. If false in conjunction with
 *                                      `$child_of` also being false, both arguments will be disregarded.
 *                                      Default true.
 *     @type array        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type array        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. Default -1, or no restriction.
 *     @type string|array $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string       $post_status  A comma-separated list of post status types to include.
 *                                      Default 'publish'.
 * }
 * @return array|false List of pages matching defaults or `$args`.
 */
function get_pages($args = array())
{
    global $wpdb;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $r = wp_parse_args($args, $defaults);
    $number = (int) $r['number'];
    $offset = (int) $r['offset'];
    $child_of = (int) $r['child_of'];
    $hierarchical = $r['hierarchical'];
    $exclude = $r['exclude'];
    $meta_key = $r['meta_key'];
    $meta_value = $r['meta_value'];
    $parent = $r['parent'];
    $post_status = $r['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($r['post_type'], $hierarchical_post_types)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key.
    $key = md5(serialize(wp_array_slice_assoc($r, array_keys($defaults))));
    $last_changed = wp_cache_get('last_changed', 'posts');
    if (!$last_changed) {
        $last_changed = microtime();
        wp_cache_set('last_changed', $last_changed, 'posts');
    }
    $cache_key = "get_pages:{$key}:{$last_changed}";
    if ($cache = wp_cache_get($cache_key, 'posts')) {
        // Convert to WP_Post instances.
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $r);
        return $pages;
    }
    $inclusions = '';
    if (!empty($r['include'])) {
        $child_of = 0;
        //ignore child_of, parent, exclude, meta_key, and meta_value params if using include
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($r['include']);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($r['authors'])) {
        $post_authors = preg_split('/[\s,]+/', $r['authors']);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                //Do we have an author id or an author login?
                if (0 == intval($post_author)) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' == $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' != $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 == count($post_status)) {
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status = %s", $r['post_type'], reset($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $r['post_type']);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $r['sort_column']) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($r['sort_order']);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'))) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= " ORDER BY " . $sort_column . " " . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $r);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once.
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($r['exclude_tree'])) {
        $exclude = wp_parse_id_list($r['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances
    $pages = array_map('get_post', $pages);
    /**
     * Filters the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param array $pages List of pages to retrieve.
     * @param array $r     Array of get_pages() arguments.
     */
    return apply_filters('get_pages', $pages, $r);
}

WordPress Version: 4.4

/**
 * Retrieve a list of pages.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 1.5.0
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of. Note: The value
 *                                      of `$hierarchical` has no bearing on whether `$child_of` returns
 *                                      hierarchical results. Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. If false in conjunction with
 *                                      `$child_of` also being false, both arguments will be disregarded.
 *                                      Default true.
 *     @type array        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type array        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. Default -1, or no restriction.
 *     @type string|array $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string       $post_status  A comma-separated list of post status types to include.
 *                                      Default 'publish'.
 * }
 * @return array|false List of pages matching defaults or `$args`.
 */
function get_pages($args = array())
{
    global $wpdb;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $r = wp_parse_args($args, $defaults);
    $number = (int) $r['number'];
    $offset = (int) $r['offset'];
    $child_of = (int) $r['child_of'];
    $hierarchical = $r['hierarchical'];
    $exclude = $r['exclude'];
    $meta_key = $r['meta_key'];
    $meta_value = $r['meta_value'];
    $parent = $r['parent'];
    $post_status = $r['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($r['post_type'], $hierarchical_post_types)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key.
    $key = md5(serialize(wp_array_slice_assoc($r, array_keys($defaults))));
    $last_changed = wp_cache_get('last_changed', 'posts');
    if (!$last_changed) {
        $last_changed = microtime();
        wp_cache_set('last_changed', $last_changed, 'posts');
    }
    $cache_key = "get_pages:{$key}:{$last_changed}";
    if ($cache = wp_cache_get($cache_key, 'posts')) {
        // Convert to WP_Post instances.
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $r);
        return $pages;
    }
    $inclusions = '';
    if (!empty($r['include'])) {
        $child_of = 0;
        //ignore child_of, parent, exclude, meta_key, and meta_value params if using include
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($r['include']);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($r['authors'])) {
        $post_authors = preg_split('/[\s,]+/', $r['authors']);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                //Do we have an author id or an author login?
                if (0 == intval($post_author)) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' == $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' != $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 == count($post_status)) {
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status = %s", $r['post_type'], reset($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $r['post_type']);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $r['sort_column']) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($r['sort_order']);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'))) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= " ORDER BY " . $sort_column . " " . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $r);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once.
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($r['exclude_tree'])) {
        $exclude = wp_parse_id_list($r['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances
    $pages = array_map('get_post', $pages);
    /**
     * Filter the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param array $pages List of pages to retrieve.
     * @param array $r     Array of get_pages() arguments.
     */
    return apply_filters('get_pages', $pages, $r);
}

WordPress Version: 4.3

/**
 * Retrieve a list of pages.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 1.5.0
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of.
 *                                      Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. Default true.
 *     @type array        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type array        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. `$hierarchical` must be false.
 *                                      Default -1, or no restriction.
 *     @type string|array $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string       $post_status  A comma-separated list of post status types to include.
 *                                      Default 'publish'.
 * }
 * @return array|false List of pages matching defaults or `$args`.
 */
function get_pages($args = array())
{
    global $wpdb;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $r = wp_parse_args($args, $defaults);
    $number = (int) $r['number'];
    $offset = (int) $r['offset'];
    $child_of = (int) $r['child_of'];
    $hierarchical = $r['hierarchical'];
    $exclude = $r['exclude'];
    $meta_key = $r['meta_key'];
    $meta_value = $r['meta_value'];
    $parent = $r['parent'];
    $post_status = $r['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($r['post_type'], $hierarchical_post_types)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key.
    $key = md5(serialize(wp_array_slice_assoc($r, array_keys($defaults))));
    $last_changed = wp_cache_get('last_changed', 'posts');
    if (!$last_changed) {
        $last_changed = microtime();
        wp_cache_set('last_changed', $last_changed, 'posts');
    }
    $cache_key = "get_pages:{$key}:{$last_changed}";
    if ($cache = wp_cache_get($cache_key, 'posts')) {
        // Convert to WP_Post instances.
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $r);
        return $pages;
    }
    $inclusions = '';
    if (!empty($r['include'])) {
        $child_of = 0;
        //ignore child_of, parent, exclude, meta_key, and meta_value params if using include
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($r['include']);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($r['authors'])) {
        $post_authors = preg_split('/[\s,]+/', $r['authors']);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                //Do we have an author id or an author login?
                if (0 == intval($post_author)) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' == $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' != $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 == count($post_status)) {
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status = %s", $r['post_type'], reset($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $r['post_type']);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $r['sort_column']) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($r['sort_order']);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'))) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= " ORDER BY " . $sort_column . " " . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $r);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once.
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($r['exclude_tree'])) {
        $exclude = wp_parse_id_list($r['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances
    $pages = array_map('get_post', $pages);
    /**
     * Filter the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param array $pages List of pages to retrieve.
     * @param array $r     Array of get_pages() arguments.
     */
    return apply_filters('get_pages', $pages, $r);
}

WordPress Version: 4.2

/**
 * Retrieve a list of pages.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 1.5.0
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of.
 *                                      Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. Default true.
 *     @type array        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type array        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. `$hierarchical` must be false.
 *                                      Default -1, or no restriction.
 *     @type string|array $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string       $post_status  A comma-separated list of post status types to include.
 *                                      Default 'publish'.
 * }
 * @return array List of pages matching defaults or `$args`.
 */
function get_pages($args = array())
{
    global $wpdb;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $r = wp_parse_args($args, $defaults);
    $number = (int) $r['number'];
    $offset = (int) $r['offset'];
    $child_of = (int) $r['child_of'];
    $hierarchical = $r['hierarchical'];
    $exclude = $r['exclude'];
    $meta_key = $r['meta_key'];
    $meta_value = $r['meta_value'];
    $parent = $r['parent'];
    $post_status = $r['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($r['post_type'], $hierarchical_post_types)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key.
    $key = md5(serialize(wp_array_slice_assoc($r, array_keys($defaults))));
    $last_changed = wp_cache_get('last_changed', 'posts');
    if (!$last_changed) {
        $last_changed = microtime();
        wp_cache_set('last_changed', $last_changed, 'posts');
    }
    $cache_key = "get_pages:{$key}:{$last_changed}";
    if ($cache = wp_cache_get($cache_key, 'posts')) {
        // Convert to WP_Post instances.
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $r);
        return $pages;
    }
    $inclusions = '';
    if (!empty($r['include'])) {
        $child_of = 0;
        //ignore child_of, parent, exclude, meta_key, and meta_value params if using include
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($r['include']);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($r['authors'])) {
        $post_authors = preg_split('/[\s,]+/', $r['authors']);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                //Do we have an author id or an author login?
                if (0 == intval($post_author)) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' == $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' != $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 == count($post_status)) {
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status = %s", $r['post_type'], reset($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $r['post_type']);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $r['sort_column']) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($r['sort_order']);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'))) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= " ORDER BY " . $sort_column . " " . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $r);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once.
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($r['exclude_tree'])) {
        $exclude = wp_parse_id_list($r['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances
    $pages = array_map('get_post', $pages);
    /**
     * Filter the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param array $pages List of pages to retrieve.
     * @param array $r     Array of get_pages() arguments.
     */
    $pages = apply_filters('get_pages', $pages, $r);
    return $pages;
}

WordPress Version: 4.1

/**
 * Retrieve a list of pages.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 1.5.0
 *
 * @param array|string $args {
 *     Optional. Array or string of arguments to retrieve pages.
 *
 *     @type int          $child_of     Page ID to return child and grandchild pages of.
 *                                      Default 0, or no restriction.
 *     @type string       $sort_order   How to sort retrieved pages. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type string       $sort_column  What columns to sort pages by, comma-separated. Accepts 'post_author',
 *                                      'post_date', 'post_title', 'post_name', 'post_modified', 'menu_order',
 *                                      'post_modified_gmt', 'post_parent', 'ID', 'rand', 'comment_count'.
 *                                      'post_' can be omitted for any values that start with it.
 *                                      Default 'post_title'.
 *     @type bool         $hierarchical Whether to return pages hierarchically. Default true.
 *     @type array        $exclude      Array of page IDs to exclude. Default empty array.
 *     @type array        $include      Array of page IDs to include. Cannot be used with `$child_of`,
 *                                      `$parent`, `$exclude`, `$meta_key`, `$meta_value`, or `$hierarchical`.
 *                                      Default empty array.
 *     @type string       $meta_key     Only include pages with this meta key. Default empty.
 *     @type string       $meta_value   Only include pages with this meta value. Requires `$meta_key`.
 *                                      Default empty.
 *     @type string       $authors      A comma-separated list of author IDs. Default empty.
 *     @type int          $parent       Page ID to return direct children of. `$hierarchical` must be false.
 *                                      Default -1, or no restriction.
 *     @type string|array $exclude_tree Comma-separated string or array of page IDs to exclude.
 *                                      Default empty array.
 *     @type int          $number       The number of pages to return. Default 0, or all pages.
 *     @type int          $offset       The number of pages to skip before returning. Requires `$number`.
 *                                      Default 0.
 *     @type string       $post_type    The post type to query. Default 'page'.
 *     @type string       $post_status  A comma-separated list of post status types to include.
 *                                      Default 'publish'.
 * }
 * @return array List of pages matching defaults or `$args`.
 */
function get_pages($args = array())
{
    global $wpdb;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $r = wp_parse_args($args, $defaults);
    $number = (int) $r['number'];
    $offset = (int) $r['offset'];
    $child_of = (int) $r['child_of'];
    $hierarchical = $r['hierarchical'];
    $exclude = $r['exclude'];
    $meta_key = $r['meta_key'];
    $meta_value = $r['meta_value'];
    $parent = $r['parent'];
    $post_status = $r['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($r['post_type'], $hierarchical_post_types)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key.
    $key = md5(serialize(wp_array_slice_assoc($r, array_keys($defaults))));
    $last_changed = wp_cache_get('last_changed', 'posts');
    if (!$last_changed) {
        $last_changed = microtime();
        wp_cache_set('last_changed', $last_changed, 'posts');
    }
    $cache_key = "get_pages:{$key}:{$last_changed}";
    if ($cache = wp_cache_get($cache_key, 'posts')) {
        // Convert to WP_Post instances.
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $r);
        return $pages;
    }
    $inclusions = '';
    if (!empty($r['include'])) {
        $child_of = 0;
        //ignore child_of, parent, exclude, meta_key, and meta_value params if using include
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($r['include']);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($r['authors'])) {
        $post_authors = preg_split('/[\s,]+/', $r['authors']);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                //Do we have an author id or an author login?
                if (0 == intval($post_author)) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' == $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' != $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 == count($post_status)) {
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status = %s", $r['post_type'], array_shift($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $r['post_type']);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $r['sort_column']) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($r['sort_order']);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'))) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= " ORDER BY " . $sort_column . " " . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $r);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once.
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($r['exclude_tree'])) {
        $exclude = wp_parse_id_list($r['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances
    $pages = array_map('get_post', $pages);
    /**
     * Filter the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param array $pages List of pages to retrieve.
     * @param array $r     Array of get_pages() arguments.
     */
    $pages = apply_filters('get_pages', $pages, $r);
    return $pages;
}

WordPress Version: 4.0

/**
 * Retrieve a list of pages.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @since 1.5.0
 *
 * @param mixed $args {
 *     Array or string of arguments. Optional.
 *
 *     @type int    'child_of'     Page ID to return child and grandchild pages of. Default 0, or no restriction.
 *     @type string 'sort_order'   How to sort retrieved pages.
 *                                 Default 'ASC'. Accepts 'ASC', 'DESC'.
 *     @type string 'sort_column'  What columns to sort pages by, comma-separated.
 *                                 Default 'post_title'. Accepts 'post_author', 'post_date', 'post_title', 'post_name',
 *                                 'post_modified', 'post_modified_gmt', 'menu_order', 'post_parent', 'ID', 'rand',
 *                                 'comment_count'. 'post_' can be omitted for any values that start with it.
 *     @type bool   'hierarchical' Whether to return pages hierarchically. Default true.
 *     @type array  'exclude'      Array of page IDs to exclude.
 *     @type array  'include'      Array of page IDs to include. Cannot be used with 'child_of', 'parent', 'exclude',
 *                                 'meta_key', 'meta_value', or 'hierarchical'.
 *     @type string 'meta_key'     Only include pages with this meta key.
 *     @type string 'meta_value'   Only include pages with this meta value.
 *     @type string 'authors'      A comma-separated list of author IDs.
 *     @type int    'parent'       Page ID to return direct children of. 'hierarchical' must be false.
 *                                 Default -1, or no restriction.
 *     @type int    'exclude_tree' Remove all children of the given ID from returned pages.
 *     @type int    'number'       The number of pages to return. Default 0, or all pages.
 *     @type int    'offset'       The number of pages to skip before returning. Requires 'number'.
 *                                 Default 0.
 *     @type string 'post_type'    The post type to query.
 *                                 Default 'page'.
 *     @type string 'post_status'  A comma-separated list of post status types to include.
 *                                 Default 'publish'.
 * }
 * @return array List of pages matching defaults or $args.
 */
function get_pages($args = array())
{
    global $wpdb;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $r = wp_parse_args($args, $defaults);
    $number = (int) $r['number'];
    $offset = (int) $r['offset'];
    $child_of = (int) $r['child_of'];
    $hierarchical = $r['hierarchical'];
    $exclude = $r['exclude'];
    $meta_key = $r['meta_key'];
    $meta_value = $r['meta_value'];
    $parent = $r['parent'];
    $post_status = $r['post_status'];
    // Make sure the post type is hierarchical.
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($r['post_type'], $hierarchical_post_types)) {
        return false;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status.
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return false;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key.
    $key = md5(serialize(wp_array_slice_assoc($r, array_keys($defaults))));
    $last_changed = wp_cache_get('last_changed', 'posts');
    if (!$last_changed) {
        $last_changed = microtime();
        wp_cache_set('last_changed', $last_changed, 'posts');
    }
    $cache_key = "get_pages:{$key}:{$last_changed}";
    if ($cache = wp_cache_get($cache_key, 'posts')) {
        // Convert to WP_Post instances.
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $r);
        return $pages;
    }
    $inclusions = '';
    if (!empty($r['include'])) {
        $child_of = 0;
        //ignore child_of, parent, exclude, meta_key, and meta_value params if using include
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($r['include']);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($r['authors'])) {
        $post_authors = preg_split('/[\s,]+/', $r['authors']);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                //Do we have an author id or an author login?
                if (0 == intval($post_author)) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' == $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' != $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 == count($post_status)) {
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status = %s", $r['post_type'], array_shift($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $r['post_type']);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $r['sort_column']) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($r['sort_order']);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'))) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= " ORDER BY " . $sort_column . " " . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $r);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once.
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($r['exclude_tree'])) {
        $exclude = wp_parse_id_list($r['exclude_tree']);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances.
    $pages = array_map('get_post', $pages);
    /**
     * Filter the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param array $pages List of pages to retrieve.
     * @param array $r     Array of get_pages() arguments.
     */
    $pages = apply_filters('get_pages', $pages, $r);
    return $pages;
}

WordPress Version: 3.9

/**
 * Retrieve a list of pages.
 *
 * @global wpdb $wpdb WordPress database abstraction object
 *
 * @since 1.5.0
 *
 * @param mixed $args {
 *     Array or string of arguments. Optional.
 *
 *     @type int    'child_of'     Page ID to return child and grandchild pages of. Default 0, or no restriction.
 *     @type string 'sort_order'   How to sort retrieved pages.
 *                                 Default 'ASC'. Accepts 'ASC', 'DESC'.
 *     @type string 'sort_column'  What columns to sort pages by, comma-separated.
 *                                 Default 'post_title'. Accepts 'post_author', 'post_date', 'post_title', 'post_name',
 *                                 'post_modified', 'post_modified_gmt', 'menu_order', 'post_parent', 'ID', 'rand',
 *                                 'comment_count'. 'post_' can be omitted for any values that start with it.
 *     @type bool   'hierarchical' Whether to return pages hierarchically. Default true.
 *     @type array  'exclude'      Array of page IDs to exclude.
 *     @type array  'include'      Array of page IDs to include. Cannot be used with 'child_of', 'parent', 'exclude',
 *                                 'meta_key', 'meta_value', or 'hierarchical'.
 *     @type string 'meta_key'     Only include pages with this meta key.
 *     @type string 'meta_value'   Only include pages with this meta value.
 *     @type string 'authors'      A comma-separated list of author IDs.
 *     @type int    'parent'       Page ID to return direct children of. 'hierarchical' must be false.
 *                                 Default -1, or no restriction.
 *     @type int    'exclude_tree' Remove all children of the given ID from returned pages.
 *     @type int    'number'       The number of pages to return. Default 0, or all pages.
 *     @type int    'offset'       The number of pages to skip before returning. Requires 'number'.
 *                                 Default 0.
 *     @type string 'post_type'    The post type to query.
 *                                 Default 'page'.
 *     @type string 'post_status'  A comma-separated list of post status types to include.
 *                                 Default 'publish'.
 * }
 * @return array List of pages matching defaults or $args.
 */
function get_pages($args = array())
{
    global $wpdb;
    $pages = false;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => array(), 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $r = wp_parse_args($args, $defaults);
    extract($r, EXTR_SKIP);
    $number = (int) $number;
    $offset = (int) $offset;
    // Make sure the post type is hierarchical
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($post_type, $hierarchical_post_types)) {
        return $pages;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return $pages;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key
    $key = md5(serialize(compact(array_keys($defaults))));
    $last_changed = wp_cache_get('last_changed', 'posts');
    if (!$last_changed) {
        $last_changed = microtime();
        wp_cache_set('last_changed', $last_changed, 'posts');
    }
    $cache_key = "get_pages:{$key}:{$last_changed}";
    if ($cache = wp_cache_get($cache_key, 'posts')) {
        // Convert to WP_Post instances
        $pages = array_map('get_post', $cache);
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', $pages, $r);
        return $pages;
    }
    if (!is_array($cache)) {
        $cache = array();
    }
    $inclusions = '';
    if (!empty($include)) {
        $child_of = 0;
        //ignore child_of, parent, exclude, meta_key, and meta_value params if using include
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($include);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($authors)) {
        $post_authors = preg_split('/[\s,]+/', $authors);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                //Do we have an author id or an author login?
                if (0 == intval($post_author)) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' == $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' != $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 == count($post_status)) {
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status = %s", $post_type, array_shift($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $post_type);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $sort_column) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($sort_order);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'))) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= " ORDER BY " . $sort_column . " " . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        /** This filter is documented in wp-includes/post.php */
        $pages = apply_filters('get_pages', array(), $r);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($exclude_tree)) {
        $exclude = wp_parse_id_list($exclude_tree);
        foreach ($exclude as $id) {
            $children = get_page_children($id, $pages);
            foreach ($children as $child) {
                $exclude[] = $child->ID;
            }
        }
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $exclude)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances
    $pages = array_map('get_post', $pages);
    /**
     * Filter the retrieved list of pages.
     *
     * @since 2.1.0
     *
     * @param array $pages List of pages to retrieve.
     * @param array $r     Array of get_pages() arguments.
     */
    $pages = apply_filters('get_pages', $pages, $r);
    return $pages;
}

WordPress Version: 7.1

/**
 * Retrieve a list of pages.
 *
 * @global wpdb $wpdb WordPress database abstraction object
 *
 * @since 1.5.0
 *
 * @param mixed $args {
 *     Array or string of arguments. Optional.
 *
 *     @type int    'child_of'     Page ID to return child and grandchild pages of. Default 0, or no restriction.
 *     @type string 'sort_order'   How to sort retrieved pages.
 *                                 Default 'ASC'. Accepts 'ASC', 'DESC'.
 *     @type string 'sort_column'  What columns to sort pages by, comma-separated.
 *                                 Default 'post_title'. Accepts 'post_author', 'post_date', 'post_title', 'post_name',
 *                                 'post_modified', 'post_modified_gmt', 'menu_order', 'post_parent', 'ID', 'rand',
 *                                 'comment_count'. 'post_' can be omitted for any values that start with it.
 *     @type bool   'hierarchical' Whether to return pages hierarchically. Default true.
 *     @type array  'exclude'      Array of page IDs to exclude.
 *     @type array  'include'      Array of page IDs to include. Cannot be used with 'child_of', 'parent', 'exclude',
 *                                 'meta_key', 'meta_value', or 'hierarchical'.
 *     @type string 'meta_key'     Only include pages with this meta key.
 *     @type string 'meta_value'   Only include pages with this meta value.
 *     @type string 'authors'      A comma-separated list of author IDs.
 *     @type int    'parent'       Page ID to return direct children of. 'hierarchical' must be false.
 *                                 Default -1, or no restriction.
 *     @type int    'exclude_tree' Remove all children of the given ID from returned pages.
 *     @type int    'number'       The number of pages to return. Default 0, or all pages.
 *     @type int    'offset'       The number of pages to skip before returning. Requires 'number'.
 *                                 Default 0.
 *     @type string 'post_type'    The post type to query.
 *                                 Default 'page'.
 *     @type string 'post_status'  A comma-separated list of post status types to include.
 *                                 Default 'publish'.
 * }
 * @return array List of pages matching defaults or $args.
 */
function get_pages($args = array())
{
    global $wpdb;
    $pages = false;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => '', 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $r = wp_parse_args($args, $defaults);
    extract($r, EXTR_SKIP);
    $number = (int) $number;
    $offset = (int) $offset;
    // Make sure the post type is hierarchical
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($post_type, $hierarchical_post_types)) {
        return $pages;
    }
    if ($parent > 0 && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return $pages;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key
    $key = md5(serialize(compact(array_keys($defaults))));
    $last_changed = wp_cache_get('last_changed', 'posts');
    if (!$last_changed) {
        $last_changed = microtime();
        wp_cache_set('last_changed', $last_changed, 'posts');
    }
    $cache_key = "get_pages:{$key}:{$last_changed}";
    if ($cache = wp_cache_get($cache_key, 'posts')) {
        // Convert to WP_Post instances
        $pages = array_map('get_post', $cache);
        $pages = apply_filters('get_pages', $pages, $r);
        return $pages;
    }
    if (!is_array($cache)) {
        $cache = array();
    }
    $inclusions = '';
    if (!empty($include)) {
        $child_of = 0;
        //ignore child_of, parent, exclude, meta_key, and meta_value params if using include
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($include);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($authors)) {
        $post_authors = preg_split('/[\s,]+/', $authors);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                //Do we have an author id or an author login?
                if (0 == intval($post_author)) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' == $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' != $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 == count($post_status)) {
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status = %s", $post_type, array_shift($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $post_type);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $sort_column) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($sort_order);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'))) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= " ORDER BY " . $sort_column . " " . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        $pages = apply_filters('get_pages', array(), $r);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($exclude_tree)) {
        $exclude = (int) $exclude_tree;
        $children = get_page_children($exclude, $pages);
        $excludes = array();
        foreach ($children as $child) {
            $excludes[] = $child->ID;
        }
        $excludes[] = $exclude;
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $excludes)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances
    $pages = array_map('get_post', $pages);
    $pages = apply_filters('get_pages', $pages, $r);
    return $pages;
}

WordPress Version: 3.7

/**
 * Retrieve a list of pages.
 *
 * @global wpdb $wpdb WordPress database abstraction object
 *
 * @since 1.5.0
 *
 * @param mixed $args {
 *     Array or string of arguments. Optional.
 *
 *     @type int    'child_of'     Page ID to return child and grandchild pages of. Default 0, or no restriction.
 *     @type string 'sort_order'   How to sort retrieved pages.
 *                                 Default 'ASC'. Accepts 'ASC', 'DESC'.
 *     @type string 'sort_column'  What columns to sort pages by, comma-separated.
 *                                 Default 'post_title'. Accepts 'post_author', 'post_date', 'post_title', 'post_name',
 *                                 'post_modified', 'post_modified_gmt', 'menu_order', 'post_parent', 'ID', 'rand',
 *                                 'comment_count'. 'post_' can be omitted for any values that start with it.
 *     @type bool   'hierarchical' Whether to return pages hierarchically. Default true.
 *     @type array  'exclude'      Array of page IDs to exclude.
 *     @type array  'include'      Array of page IDs to include. Cannot be used with 'child_of', 'parent', 'exclude',
 *                                 'meta_key', 'meta_value', or 'hierarchical'.
 *     @type string 'meta_key'     Only include pages with this meta key.
 *     @type string 'meta_value'   Only include pages with this meta value.
 *     @type string 'authors'      A comma-separated list of author IDs.
 *     @type int    'parent'       Page ID to return direct children of. 'hierarchical' must be false.
 *                                 Default -1, or no restriction.
 *     @type int    'exclude_tree' Remove all children of the given ID from returned pages.
 *     @type int    'number'       The number of pages to return. Default 0, or all pages.
 *     @type int    'offset'       The number of pages to skip before returning. Requires 'number'.
 *                                 Default 0.
 *     @type string 'post_type'    The post type to query.
 *                                 Default 'page'.
 *     @type string 'post_status'  A comma-separated list of post status types to include.
 *                                 Default 'publish'.
 * }
 * @return array List of pages matching defaults or $args.
 */
function get_pages($args = array())
{
    global $wpdb;
    $pages = false;
    $defaults = array('child_of' => 0, 'sort_order' => 'ASC', 'sort_column' => 'post_title', 'hierarchical' => 1, 'exclude' => array(), 'include' => array(), 'meta_key' => '', 'meta_value' => '', 'authors' => '', 'parent' => -1, 'exclude_tree' => '', 'number' => '', 'offset' => 0, 'post_type' => 'page', 'post_status' => 'publish');
    $r = wp_parse_args($args, $defaults);
    extract($r, EXTR_SKIP);
    $number = (int) $number;
    $offset = (int) $offset;
    // Make sure the post type is hierarchical
    $hierarchical_post_types = get_post_types(array('hierarchical' => true));
    if (!in_array($post_type, $hierarchical_post_types)) {
        return $pages;
    }
    if ($parent && !$child_of) {
        $hierarchical = false;
    }
    // Make sure we have a valid post status
    if (!is_array($post_status)) {
        $post_status = explode(',', $post_status);
    }
    if (array_diff($post_status, get_post_stati())) {
        return $pages;
    }
    // $args can be whatever, only use the args defined in defaults to compute the key
    $key = md5(serialize(compact(array_keys($defaults))));
    $last_changed = wp_cache_get('last_changed', 'posts');
    if (!$last_changed) {
        $last_changed = microtime();
        wp_cache_set('last_changed', $last_changed, 'posts');
    }
    $cache_key = "get_pages:{$key}:{$last_changed}";
    if ($cache = wp_cache_get($cache_key, 'posts')) {
        // Convert to WP_Post instances
        $pages = array_map('get_post', $cache);
        $pages = apply_filters('get_pages', $pages, $r);
        return $pages;
    }
    if (!is_array($cache)) {
        $cache = array();
    }
    $inclusions = '';
    if (!empty($include)) {
        $child_of = 0;
        //ignore child_of, parent, exclude, meta_key, and meta_value params if using include
        $parent = -1;
        $exclude = '';
        $meta_key = '';
        $meta_value = '';
        $hierarchical = false;
        $incpages = wp_parse_id_list($include);
        if (!empty($incpages)) {
            $inclusions = ' AND ID IN (' . implode(',', $incpages) . ')';
        }
    }
    $exclusions = '';
    if (!empty($exclude)) {
        $expages = wp_parse_id_list($exclude);
        if (!empty($expages)) {
            $exclusions = ' AND ID NOT IN (' . implode(',', $expages) . ')';
        }
    }
    $author_query = '';
    if (!empty($authors)) {
        $post_authors = preg_split('/[\s,]+/', $authors);
        if (!empty($post_authors)) {
            foreach ($post_authors as $post_author) {
                //Do we have an author id or an author login?
                if (0 == intval($post_author)) {
                    $post_author = get_user_by('login', $post_author);
                    if (empty($post_author)) {
                        continue;
                    }
                    if (empty($post_author->ID)) {
                        continue;
                    }
                    $post_author = $post_author->ID;
                }
                if ('' == $author_query) {
                    $author_query = $wpdb->prepare(' post_author = %d ', $post_author);
                } else {
                    $author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
                }
            }
            if ('' != $author_query) {
                $author_query = " AND ({$author_query})";
            }
        }
    }
    $join = '';
    $where = "{$exclusions} {$inclusions} ";
    if ('' !== $meta_key || '' !== $meta_value) {
        $join = " LEFT JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
        // meta_key and meta_value might be slashed
        $meta_key = wp_unslash($meta_key);
        $meta_value = wp_unslash($meta_value);
        if ('' !== $meta_key) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_key = %s", $meta_key);
        }
        if ('' !== $meta_value) {
            $where .= $wpdb->prepare(" AND {$wpdb->postmeta}.meta_value = %s", $meta_value);
        }
    }
    if (is_array($parent)) {
        $post_parent__in = implode(',', array_map('absint', (array) $parent));
        if (!empty($post_parent__in)) {
            $where .= " AND post_parent IN ({$post_parent__in})";
        }
    } elseif ($parent >= 0) {
        $where .= $wpdb->prepare(' AND post_parent = %d ', $parent);
    }
    if (1 == count($post_status)) {
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status = %s", $post_type, array_shift($post_status));
    } else {
        $post_status = implode("', '", $post_status);
        $where_post_type = $wpdb->prepare("post_type = %s AND post_status IN ('{$post_status}')", $post_type);
    }
    $orderby_array = array();
    $allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified', 'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent', 'ID', 'rand', 'comment_count');
    foreach (explode(',', $sort_column) as $orderby) {
        $orderby = trim($orderby);
        if (!in_array($orderby, $allowed_keys)) {
            continue;
        }
        switch ($orderby) {
            case 'menu_order':
                break;
            case 'ID':
                $orderby = "{$wpdb->posts}.ID";
                break;
            case 'rand':
                $orderby = 'RAND()';
                break;
            case 'comment_count':
                $orderby = "{$wpdb->posts}.comment_count";
                break;
            default:
                if (0 === strpos($orderby, 'post_')) {
                    $orderby = "{$wpdb->posts}." . $orderby;
                } else {
                    $orderby = "{$wpdb->posts}.post_" . $orderby;
                }
        }
        $orderby_array[] = $orderby;
    }
    $sort_column = (!empty($orderby_array)) ? implode(',', $orderby_array) : "{$wpdb->posts}.post_title";
    $sort_order = strtoupper($sort_order);
    if ('' !== $sort_order && !in_array($sort_order, array('ASC', 'DESC'))) {
        $sort_order = 'ASC';
    }
    $query = "SELECT * FROM {$wpdb->posts} {$join} WHERE ({$where_post_type}) {$where} ";
    $query .= $author_query;
    $query .= " ORDER BY " . $sort_column . " " . $sort_order;
    if (!empty($number)) {
        $query .= ' LIMIT ' . $offset . ',' . $number;
    }
    $pages = $wpdb->get_results($query);
    if (empty($pages)) {
        $pages = apply_filters('get_pages', array(), $r);
        return $pages;
    }
    // Sanitize before caching so it'll only get done once
    $num_pages = count($pages);
    for ($i = 0; $i < $num_pages; $i++) {
        $pages[$i] = sanitize_post($pages[$i], 'raw');
    }
    // Update cache.
    update_post_cache($pages);
    if ($child_of || $hierarchical) {
        $pages = get_page_children($child_of, $pages);
    }
    if (!empty($exclude_tree)) {
        $exclude = (int) $exclude_tree;
        $children = get_page_children($exclude, $pages);
        $excludes = array();
        foreach ($children as $child) {
            $excludes[] = $child->ID;
        }
        $excludes[] = $exclude;
        $num_pages = count($pages);
        for ($i = 0; $i < $num_pages; $i++) {
            if (in_array($pages[$i]->ID, $excludes)) {
                unset($pages[$i]);
            }
        }
    }
    $page_structure = array();
    foreach ($pages as $page) {
        $page_structure[] = $page->ID;
    }
    wp_cache_set($cache_key, $page_structure, 'posts');
    // Convert to WP_Post instances
    $pages = array_map('get_post', $pages);
    $pages = apply_filters('get_pages', $pages, $r);
    return $pages;
}