do_enclose() │ WP 1.5.0

Checks the specified post for links to Video and Audio in its content. If links are found, it adds these URLs to the meta-fields enclosure.

Before adding the next meta-field enclosure, it checks if such data already exists. It removes the meta-field enclosure that were deleted from the post.

This is an internal WP function. It is triggered in the function do_all_enclosures(), which in turn is executed by cron on the hook do_all_pings:

add_action( 'publish_post', '_publish_post_hook', 5, 1 ); // here the cron task is created
	→ wp_schedule_single_event( time(), 'do_pings' );
		// this is triggered by Cron
		→ add_action( 'do_pings', 'do_all_pings', 10, 0 );
			→ add_action( 'do_all_pings', 'do_all_enclosures', 10, 0 );

How it works read more here.

Also read: WP Cron.

Uses: get_enclosed(), wp_extract_urls()
Hooks from the function

Returns

null|false. Null on success and false if the post is not found.

Usage

do_enclose( $content, $post );
$content(string|null) (required)
Usually here is specified null! The content of the post. If null, the post_content field from $post is used.
$post(int|WP_Post) (required)
ID of the post or post object.

Examples

0

#1 Using in the WP core

See the code of function do_all_enclosures().

Notes

  • Global. wpdb. $wpdb WordPress database abstraction object.

Changelog

Since 1.5.0 Introduced.
Since 5.3.0 The $content parameter was made optional, and the $post parameter was updated to accept a post ID or a WP_Post object.
Since 5.6.0 The $content parameter is no longer optional, but passing null to skip it is still supported.

do_enclose() code WP 7.0

wp-includes/functions.php 
function do_enclose( $content, $post ) {
	global $wpdb;

	// @todo Tidy this code and make the debug code optional.
	require_once ABSPATH . WPINC . '/class-IXR.php';

	$post = get_post( $post );
	if ( ! $post ) {
		return false;
	}

	if ( null === $content ) {
		$content = $post->post_content;
	}

	$post_links = array();

	$pung = get_enclosed( $post->ID );

	$post_links_temp = wp_extract_urls( $content );

	foreach ( $pung as $link_test ) {
		// Link is no longer in post.
		if ( ! in_array( $link_test, $post_links_temp, true ) ) {
			$mids = $wpdb->get_col( $wpdb->prepare( "SELECT meta_id FROM $wpdb->postmeta WHERE post_id = %d AND meta_key = 'enclosure' AND meta_value LIKE %s", $post->ID, $wpdb->esc_like( $link_test ) . '%' ) );
			foreach ( $mids as $mid ) {
				delete_metadata_by_mid( 'post', $mid );
			}
		}
	}

	foreach ( (array) $post_links_temp as $link_test ) {
		// If we haven't pung it already.
		if ( ! in_array( $link_test, $pung, true ) ) {
			$test = parse_url( $link_test );
			if ( false === $test ) {
				continue;
			}
			if ( isset( $test['query'] ) ) {
				$post_links[] = $link_test;
			} elseif ( isset( $test['path'] ) && ( '/' !== $test['path'] ) && ( '' !== $test['path'] ) ) {
				$post_links[] = $link_test;
			}
		}
	}

	/**
	 * Filters the list of enclosure links before querying the database.
	 *
	 * Allows for the addition and/or removal of potential enclosures to save
	 * to postmeta before checking the database for existing enclosures.
	 *
	 * @since 4.4.0
	 *
	 * @param string[] $post_links An array of enclosure links.
	 * @param int      $post_id    Post ID.
	 */
	$post_links = apply_filters( 'enclosure_links', $post_links, $post->ID );

	foreach ( (array) $post_links as $url ) {
		$url = strip_fragment_from_url( $url );

		if ( '' !== $url && ! $wpdb->get_var( $wpdb->prepare( "SELECT post_id FROM $wpdb->postmeta WHERE post_id = %d AND meta_key = 'enclosure' AND meta_value LIKE %s", $post->ID, $wpdb->esc_like( $url ) . '%' ) ) ) {

			$headers = wp_get_http_headers( $url );
			if ( $headers ) {
				$len           = (int) ( $headers['Content-Length'] ?? 0 );
				$type          = $headers['Content-Type'] ?? '';
				$allowed_types = array( 'video', 'audio' );

				// Check to see if we can figure out the mime type from the extension.
				$url_parts = parse_url( $url );
				if ( false !== $url_parts && ! empty( $url_parts['path'] ) ) {
					$extension = pathinfo( $url_parts['path'], PATHINFO_EXTENSION );
					if ( ! empty( $extension ) ) {
						foreach ( wp_get_mime_types() as $exts => $mime ) {
							if ( preg_match( '!^(' . $exts . ')$!i', $extension ) ) {
								$type = $mime;
								break;
							}
						}
					}
				}

				if ( in_array( substr( $type, 0, strpos( $type, '/' ) ), $allowed_types, true ) ) {
					add_post_meta( $post->ID, 'enclosure', "$url\n$len\n$mime\n" );
				}
			}
		}
	}
}

Cron API