WordPress Version: 4.7
/**
* Determines whether the current request is a WordPress Ajax request.
*
* @since 4.7.0
*
* @return bool True if it's a WordPress Ajax request, false otherwise.
*/
function wp_doing_ajax()
{
/**
* Filters whether the current request is a WordPress Ajax request.
*
* @since 4.7.0
*
* @param bool $wp_doing_ajax Whether the current request is a WordPress Ajax request.
*/
return apply_filters('wp_doing_ajax', defined('DOING_AJAX') && DOING_AJAX);
}