nocache_headers

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

WordPress Version: 6.3

/**
 * Sets the HTTP headers to prevent caching for the different browsers.
 *
 * Different browsers support different nocache headers, so several
 * headers must be sent so that all of them get the point that no
 * caching should occur.
 *
 * @since 2.0.0
 *
 * @see wp_get_nocache_headers()
 */
function nocache_headers()
{
    if (headers_sent()) {
        return;
    }
    $headers = wp_get_nocache_headers();
    unset($headers['Last-Modified']);
    header_remove('Last-Modified');
    foreach ($headers as $name => $field_value) {
        header("{$name}: {$field_value}");
    }
}

WordPress Version: 6.1

/**
 * Sets the headers to prevent caching for the different browsers.
 *
 * Different browsers support different nocache headers, so several
 * headers must be sent so that all of them get the point that no
 * caching should occur.
 *
 * @since 2.0.0
 *
 * @see wp_get_nocache_headers()
 */
function nocache_headers()
{
    if (headers_sent()) {
        return;
    }
    $headers = wp_get_nocache_headers();
    unset($headers['Last-Modified']);
    header_remove('Last-Modified');
    foreach ($headers as $name => $field_value) {
        header("{$name}: {$field_value}");
    }
}

WordPress Version: 5.3

/**
 * Set the headers to prevent caching for the different browsers.
 *
 * Different browsers support different nocache headers, so several
 * headers must be sent so that all of them get the point that no
 * caching should occur.
 *
 * @since 2.0.0
 *
 * @see wp_get_nocache_headers()
 */
function nocache_headers()
{
    if (headers_sent()) {
        return;
    }
    $headers = wp_get_nocache_headers();
    unset($headers['Last-Modified']);
    header_remove('Last-Modified');
    foreach ($headers as $name => $field_value) {
        header("{$name}: {$field_value}");
    }
}

WordPress Version: 4.0

/**
 * Set the headers to prevent caching for the different browsers.
 *
 * Different browsers support different nocache headers, so several
 * headers must be sent so that all of them get the point that no
 * caching should occur.
 *
 * @since 2.0.0
 *
 * @see wp_get_nocache_headers()
 */
function nocache_headers()
{
    $headers = wp_get_nocache_headers();
    unset($headers['Last-Modified']);
    // In PHP 5.3+, make sure we are not sending a Last-Modified header.
    if (function_exists('header_remove')) {
        @header_remove('Last-Modified');
    } else {
        // In PHP 5.2, send an empty Last-Modified header, but only as a
        // last resort to override a header already sent. #WP23021
        foreach (headers_list() as $header) {
            if (0 === stripos($header, 'Last-Modified')) {
                $headers['Last-Modified'] = '';
                break;
            }
        }
    }
    foreach ($headers as $name => $field_value) {
        @header("{$name}: {$field_value}");
    }
}

WordPress Version: 3.8

/**
 * Sets the headers to prevent caching for the different browsers.
 *
 * Different browsers support different nocache headers, so several headers must
 * be sent so that all of them get the point that no caching should occur.
 *
 * @since 2.0.0
 * @see wp_get_nocache_headers()
 */
function nocache_headers()
{
    $headers = wp_get_nocache_headers();
    unset($headers['Last-Modified']);
    // In PHP 5.3+, make sure we are not sending a Last-Modified header.
    if (function_exists('header_remove')) {
        @header_remove('Last-Modified');
    } else {
        // In PHP 5.2, send an empty Last-Modified header, but only as a
        // last resort to override a header already sent. #WP23021
        foreach (headers_list() as $header) {
            if (0 === stripos($header, 'Last-Modified')) {
                $headers['Last-Modified'] = '';
                break;
            }
        }
    }
    foreach ($headers as $name => $field_value) {
        @header("{$name}: {$field_value}");
    }
}

WordPress Version: 3.7

/**
 * Sets the headers to prevent caching for the different browsers.
 *
 * Different browsers support different nocache headers, so several headers must
 * be sent so that all of them get the point that no caching should occur.
 *
 * @since 2.0.0
 * @uses wp_get_nocache_headers()
 */
function nocache_headers()
{
    $headers = wp_get_nocache_headers();
    unset($headers['Last-Modified']);
    // In PHP 5.3+, make sure we are not sending a Last-Modified header.
    if (function_exists('header_remove')) {
        @header_remove('Last-Modified');
    } else {
        // In PHP 5.2, send an empty Last-Modified header, but only as a
        // last resort to override a header already sent. #WP23021
        foreach (headers_list() as $header) {
            if (0 === stripos($header, 'Last-Modified')) {
                $headers['Last-Modified'] = '';
                break;
            }
        }
    }
    foreach ($headers as $name => $field_value) {
        @header("{$name}: {$field_value}");
    }
}