Wordpress SearchWP: Substitute Post for Attachment in Search Results

searchwp_results_substitute_post_for_attachment.php

<?php

/**
 * This function will see if a PDF or other "attachment" post-type returned by SearchWP
 * is present in a custom field in a regular post, and will return that post instead. Note
 * this will only process documents which are referenced via the "attachment" post type.
 *
 * For example, you may have a product specification PDF and would like it in the search
 * results, but would rather people got to it by visiting the product page itself.
 *
 * There are some filters you can set to provide some control over both the attachments
 * processed and the post-types they might be attached to.
 *
 * The ideal use case is a custom post type which sets a custom field to the ID or filename
 * of a file from the media library.
 *
 */

// SearchWP hook

add_filter( 'searchwp_results', 'my_searchwp_search_results', 10, 2 );

/**
 * Substitute a post for an attachment by looking for attachment URL or ID in custom post field
 *
 * @param       $posts  : Array of WP_Post objects from SearchWP
 * @param array $params : Parameters sent by SearchWP (as of 2.4.8 - unused below, but available):
 *                          'terms'       => Terms searched for
 *                          'page'        => Which page of search results this is
 *                          'order'       => Results return order (ex: DESC)
 *                          'foundPosts'  => Number of found posts in results
 *                          'maxNumPages' => Maximum number of result pages
 *                          'engine'      => Which SearchWP engine is in use
 *
 * @return array
 */
function my_searchwp_search_results( $posts, $params = array() ) {

	$results = $posts;
	$attachments   = array();

	/**
	 * Required: $custom_meta_field (string)
	 *   The field in the post you wish to substitute which will be checked for the
	 *   attachment filename or ID. This field will be matched against the attachment URL
	 *   and the attachment ID, if it matches either the substitution will occur.
	 */

	$custom_meta_field = '';

	/**
	 * Optional: $custom_description_field (string)
	 *   SearchWP normally returns the excerpt. Setting a custom field value here will set
	 *   the WP_Post excerpt to be the contents of this field. Note: Not escaped or otherwise
	 *   filtered, use caution or add checks!
	 */

	$custom_description_field = null;

	// Initial filtering of attachments by their properties:

	/**
	 * Optional: $upload_directory_filter (string)
	 *   Limit the substitution to attachments uploaded to directory with this string in path.
	 *   Matched to ANY part of the path, be sure to be as specific as possible.
	 *   Set to 'null' to check all attachments.
	 */

	$upload_directory_filter = null;

	/**
	 * Optional: $filename_filter (string)
	 *   Limit the substitution to attachments with this string as part of filename.
	 *   Matched to ANY part of the filename, be sure to be as specific as possible.
	 *   Set to 'null' to check all attachments.
	 */

	$filename_filter = null;

	/**
	 * Optional: $extension_filter (array)
	 *   Limit substitution to specific attachment types. Empty array
	 *   allows all extensions. Example: array( 'pdf', 'txt' )
	 */

	$extension_filter = array();

	/**
	 * Optional: $hide_others_filter (bool)
	 *   If you set filters above and want non-matching attachments removed from search
	 *   results entirely, set below to true
	 */

	$hide_others_filter = false;

	// Matching filtered attachments:

	/**
	 * Optional: $post_type_filter (array)
	 *   Limit substitution to specific post types. Cannot be "attachment". Empty array
	 *   dfaults to "post". Example: array( 'page', 'my_custom_post' )
	 */

	$post_types = array();


	/**
	 * Optional: $hide_filtered_attachments (bool)
	 *   Set to true if you want attachments hidden which passed initial
	 *   filtering (path/name/extension) but cannot be matched against selected posts/fields
	 */

	$hide_filtered_attachments = false;


	// if an attachment is in $results, add to $attachments

	foreach ( $results as $key => $post ) {

		// see if it's an attachment

		if ( $post->post_type == 'attachment' ) {

			// get the attachment URL and parse it

			$check_file  = wp_get_attachment_url( $post->ID );
			$file_parsed = parse_url( $check_file );

			// there has to be a path to proceed

			if ( isset ( $file_parsed['path'] ) ) {

				// use pathinfo to get filename

				$check_file_info = pathinfo( $file_parsed['path'] );

				// filter by path contents

				if ( $upload_directory_filter !== null && ! strstr( $check_file_info['dirname'], $upload_directory_filter ) ) {
					$check_file_info = '';
				}

				// filter by filename contents

				if ( $filename_filter !== null && ! strstr( $check_file_info['filename'], $filename_filter ) ) {
					$check_file_info = '';
				}

				// filter by extension

				if ( ! empty( $extension_filter ) && ! in_array( $check_file_info['extension'], $extension_filter ) ) {
					$check_file_info = '';
				}

				// did we find a filename?

				if ( isset( $check_file_info['basename'] ) && $check_file_info['basename'] ) {

					// Use the $posts key to facilitate later substitution

					$attachments[ $key ]['path'] = $file_parsed['path'];
					$attachments[ $key ]['ID'] = $post->ID;
				}
			}

			// if $hide_others_filter is true and attachment was not added to $attachments, remove from results

			if ( ! isset( $attachments[ $key ]['file'] ) && $hide_others_filter === true ) {
				unset( $results[$key] );
			}
		}
	}

	// if $attachments were found, match them against posts

	if ( ! empty( $attachments ) ) {

		// holds our posts to check for our filtered attachments

		$check_posts = array();

		// if $post_types was set

		$arg_post_type = '';
		if ( ! empty( $post_types ) ) {
			$arg_post_type = $post_types;
		}

		/**
		 * Note, this is a very simple query. You may or will want to modify to account for
		 * taxonomy filtering, etc., etc.
		 */

		$args = array(
			'post_type'      => $arg_post_type,
			'posts_per_page' => -1,
			'post_status'    => 'publish',
		);
		$all_posts = new WP_Query( $args );

		// did we find posts?

		if ( ! empty( $all_posts->posts ) ) {
			$check_posts = $all_posts->posts;
		}
		wp_reset_postdata();

		// now we check those attachments to find their matching toolbox posts

		foreach ( $attachments as $attachment_key => $attachment ) {

			// flag to check for applying $hide_filtered_attachments

			$ok = false;

			foreach ( $check_posts as $post ) {

				// get custom meta field which contains the attachment ID or filepath

				$check_thisfile = get_post_meta( $post->ID, $custom_meta_field, true );

				// did we get a value back?

				if ( $check_thisfile ) {

					// if it is numeric, it's an ID
					if ( is_numeric( $check_thisfile ) && ( intval( $check_thisfile ) == floatval( $check_thisfile ) ) ) {

						// compare to our id, if it matches, make the substitution

						if ( intval( $check_thisfile) == intval( $attachment['ID'] ) ) {

							$results[ $attachment_key ] = $post;
							$ok = true;
							break;
						}

					} else {

						// parse the URL from the meta field

						$thisfile_parsed = parse_url( $check_thisfile );

						// if we found a path from our parsing and it matches our attachment path, make substitution

						if ( isset ( $thisfile_parsed['path'] ) && ( $thisfile_parsed['path'] == $attachment['path'] ) ) {

							$results[ $attachment_key ] = $post;
							$ok = true;
							break;
						}
					}
				}
			}

			// we made a substitution and $custom_description_field was set, make the substitution

			if ( $ok === true && $custom_description_field !== null ) {

				$results[ $attachment_key ]->post_excerpt = get_post_meta( $results[ $attachment_key ]->ID, $custom_description_field, true );
			}

			// unset the search result if we did not make a substitution and the filter is set to true

			if ( $ok === false && $hide_filtered_attachments === true ) {
				unset( $results[ $attachment_key ] );
			}
		}
	}

	// return the search results to SearchWP

	return array_values( $results );
}