export-media-with-content.php

<?php
/*
 * Plugin Name: Export media with selected content
 * Plugin URI: https://wordpress.org/plugins/export-media-with-selected-content/
 * Description: Make sure all relevant media are exported with the selected content.
 * Author: Joost de Keijzer
 * Version: 2.1.4
 * Author URI: https://dkzr.nl/
 * Requires at least: 4.5
 * Requires PHP: 7.0
 * Text Domain: export-media-with-selected-content
 */

class dkzrExportMediaWithContent {
	protected static $export_query_run = false;
	protected static $args = array();

	public function __construct() {
		// wp-admin/export.php line 119
		add_filter( 'export_args', array($this, 'export_args'), 10, 1 );

		// wp-admin/export.php line 317
		add_action( 'export_filters', array($this, 'wp_export_filters'), 10000 );

		// wp-admin/includes/export.php line 76
		add_action( 'export_wp', array($this, 'export_wp'), 10, 1 );

		// custom export_query
		add_filter( 'export_query', array($this, 'add_attachments_to_export_query'), 10, 1 );
	}

	/**
	 * Filter export arguments, only when an actual export is requested (`$_GET['download']` is set)
	 */
	public function export_args( $args ) {
		if ( isset($_GET['export-media-with-selected-content']) ) {
			$args['export-media-with-selected-content'] = (int) $_GET['export-media-with-selected-content'];
		}
		return $args;
	}

	/**
	 * Add custom export options
	 */
	public function wp_export_filters() { ?>
<p><input type="hidden" name="export-media-with-selected-content" value="0" /><label><input type="checkbox" name="export-media-with-selected-content" value="1" /> <?php esc_html_e( 'Export media with selected content', 'export-media-with-selected-content' ); ?></label></p>
<?php }

	/**
	 * Add `export_query` filter
	 */
	public function export_wp( $args ) {
		self::$args = $args;

		/**
		 * The `export_query` filter only alters the main export query. It requires the query to be a sql string starting with 'SELECT ID FROM {$wpdb->posts} '
		 */
		add_filter( 'query', array($this, 'export_query_filter'), 10, 1 );
	}

	public function export_query_filter( $query ) {
		global $wpdb;
		if (
			false === self::$export_query_run
			&& is_string($query)
			&& 0 === strpos( $query, "SELECT ID FROM {$wpdb->posts} " )
		) {
			remove_filter( 'query', array($this, 'export_query_filter'), 10 );
			self::$export_query_run = true;

			$query = apply_filters( 'export_query', $query );
		}
		return $query;
	}

	public function add_attachments_to_export_query( $query ) {
		global $wpdb;

		if ( isset( self::$args['content'], self::$args['export-media-with-selected-content'] ) && 'all' !== self::$args['content'] && 'attachment' !== self::$args['content'] && self::$args['export-media-with-selected-content'] ) {

			$attachments = array_filter( $wpdb->get_results( "SELECT ID, guid, post_parent FROM {$wpdb->posts} WHERE post_type = 'attachment'", OBJECT_K ) );
			if ( empty( $attachments ) ) {
				return $query;
			}

			$ids = array();
			$cache = array();

			/**
			 * Post thumbnails or uploaded to (post_parent)
			 */
			$posts = array_filter( $wpdb->get_col( $query ) );
			if ( $posts ) {
				$ids = $wpdb->get_col( sprintf( "SELECT meta_value FROM {$wpdb->postmeta} WHERE meta_key = '_thumbnail_id' AND post_id IN(%s)", implode(',', $posts) ) );

				foreach ( $attachments as $id => $att ) {
					if ( in_array( $att->post_parent, $posts ) ) {
						$ids[] = (int) $id;
					}
				}
			}

			/**
			 * Media in body text (attached file: media, gallery, url's)
			 */
			$attachments = $this->getPostAttachmentsMeta( $attachments );
			$attachment_map = $this->getUrlToAttachmentMap( $attachments );

			$q = str_replace( 'SELECT ID FROM ', 'SELECT post_content FROM ', $query ) . ' AND post_content REGEXP "((wp-image-|wp-att-)[0-9][0-9]*)|\\\[(gallery|playlist) |<!-- wp:(gallery|audio|image|video) |href=|src="' ;
			foreach ( $wpdb->get_col( $q ) as $text ) {
				// wp-x-ID tags content
				preg_match_all('#(wp-image-|wp-att-)(\d+)#', $text, $matches, PREG_SET_ORDER);
				foreach ($matches as $match) {
					$ids[] = (int) $match[2];
				}

				// [gallery] and [playlist] shortcode
				preg_match_all('#\[(gallery|playlist)\s+.*ids=["\']([\d\s,]*)["\'].*\]#', $text, $matches, PREG_SET_ORDER);
				foreach ($matches as $match) {
					foreach( explode( ',', $match[2] ) as $id ) {
						$ids[] = (int) $id;
					}
				}

				/** Gutenberg support **/
				// <!-- wp:gallery {"ids":[1,2,3]} -->
				preg_match_all('#<!-- wp:gallery ({.+}) -->#', $text, $matches, PREG_SET_ORDER);
				foreach ($matches as $match) {
					$match = json_decode( $match[1] );
					if ( isset( $match, $match->ids ) ) {
						foreach( $match->ids as $id ) {
							$ids[] = (int) $id;
						}
					}
				}
				// <!-- wp:audio {"id":6} --><!-- wp:image {"id":4} --><!-- wp:video {"id":5} -->
				preg_match_all('#<!-- wp:(audio|image|video) ({.*}) -->#', $text, $matches, PREG_SET_ORDER);
				foreach ($matches as $match) {
					$match = json_decode( $match[2] );
					if ( isset( $match, $match->id ) ) {
						$ids[] = (int) $match->id;
					}
				}

				// urls in text
				preg_match_all('#(href|src)\s*=\s*["\']([^"\']+)["\']#', $text, $matches, PREG_SET_ORDER);
				foreach ($matches as $match) {
					if ( isset( $cache[ $match[2] ] ) ) {
						continue;
					}

					$needle = trim($match[2]);
					if ( 0 === strpos( $needle, '#' ) || 0 === strpos( $needle, 'mailto:') ) {
						continue;
					}

					if ( ! preg_match( '|^([a-zA-Z]+:)?//|', $needle ) ) {
						// relative url
						$needle = $this->fullUrl( $needle );
					}

					if (!empty($attachment_map[$needle])) {
						$cache[ $match[2] ] = $ids[] = (int) $attachment_map[$needle];
					}
				}
			}
			$ids = array_filter( array_unique( $ids ) );

			$ids = apply_filters( 'export_query_media_ids', $ids );

			$ids = array_filter( array_unique( $ids ) );

			if ( count($ids) > 0 ) {
				if ( 0 === strpos($query, "SELECT ID FROM {$wpdb->posts} INNER JOIN {$wpdb->term_relationships} ") ) {
					// replace INNER JOIN with LEFT JOIN to allow for finding the attachments.
					$query = str_replace( "SELECT ID FROM {$wpdb->posts} INNER JOIN {$wpdb->term_relationships} ", "SELECT ID FROM {$wpdb->posts} LEFT JOIN {$wpdb->term_relationships} ", $query );
				}
				$query .= sprintf( " OR {$wpdb->posts}.ID IN (%s) ", implode(',', $ids) );
			}
		}
		return $query;
	}

	/**
	 * Load attachments in chunks - prevent from taking too much memory on big attachment lists.
	 * @param array $attachments
	 * @return array
	 */
	protected function getPostAttachmentsMeta( array $attachments ) {
		global $wpdb;

		$attachment_ids = array_keys( $attachments );
		$i = 0;
		do {
			$chunk = array_slice( $attachment_ids, $i * 1000, 1000 );
			$chunk[] = 0; // make sure that chunk is not empty
			$q = sprintf( "SELECT post_id, meta_key, meta_value FROM {$wpdb->postmeta} WHERE meta_key IN('_wp_attached_file', '_wp_attachment_metadata') AND post_id IN(%s)", implode( ',', $chunk ) );
			foreach( $wpdb->get_results( $q, ARRAY_A ) as $meta ) {
				if ( isset( $attachments[ $meta['post_id'] ] ) ) {
					$attachments[ $meta['post_id'] ]->{$meta['meta_key']} = maybe_unserialize( $meta['meta_value'] );
				}
			}
			$i++;
		} while( sizeof( $chunk ) > 1 );

		return $attachments;
	}

	/**
	 * Prepare a map for all urls to attachment object.
	 * This map lets us find them quickly by url without iterating over all of them.
	 * @return array map indexed by string (attachment full url) of attachment objects
	 */
	protected function getUrlToAttachmentMap( $attachments ) {
		$attachment_map = array();

		foreach ( $attachments as $id => $att ) {
			if ( isset( $att->_wp_attached_file ) ) {
				$hay = $this->fullUrl( $att->_wp_attached_file );
				$attachment_map[ $hay ] = (int) $att->ID;
			}

			if ( isset( $att->_wp_attachment_metadata['file'] ) ) {
				$hay = $this->fullUrl( $att->_wp_attachment_metadata['file'] );
				$attachment_map[ $hay ] = (int) $att->ID;
			}

			if ( isset( $att->_wp_attachment_metadata['file'], $att->_wp_attachment_metadata['sizes'] ) ) {
				$base = trailingslashit( dirname( $att->_wp_attachment_metadata['file'] ) );
				foreach( $att->_wp_attachment_metadata['sizes'] as $size ) {
					$hay = $this->fullUrl( $base . $size['file'] );
					$attachment_map[ $hay ] = (int) $att->ID;
				}
			}

			if ( isset( $att->guid ) ) {
				$attachment_map[ $att->guid ] = (int) $att->ID;
			}
		}

		return $attachment_map;
	}

	protected function fullUrl( $file ) {
		if ( ( $uploads = wp_get_upload_dir() ) && false === $uploads['error'] ) {
			// Check that the upload base exists in the file location.
			if ( 0 === strpos( $file, $uploads['basedir'] ) ) {
				// Replace file location with url location.
				$url = str_replace($uploads['basedir'], $uploads['baseurl'], $file);
			} elseif ( false !== strpos($file, 'wp-content/uploads') ) {
				// Get the directory name relative to the basedir (back compat for pre-2.7 uploads)
				$url = trailingslashit( $uploads['baseurl'] . '/' . _wp_get_attachment_relative_path( $file ) ) . basename( $file );
			} else {
				// It's a newly-uploaded file, therefore $file is relative to the basedir.
				$url = $uploads['baseurl'] . "/$file";
			}
			return $url;
		}
		return false;
	}
}
$dkzrExportMediaWithContent = new dkzrExportMediaWithContent();