A HitchHackers guide through WordPress

Source code

function wp_delete_attachment( $post_id, $force_delete = false ) {

	global $wpdb;



	if ( !$post = $wpdb->get_row( $wpdb->prepare("SELECT * FROM $wpdb->posts WHERE ID = %d", $post_id) ) )

		return $post;



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

		return false;



	if ( !$force_delete && EMPTY_TRASH_DAYS && MEDIA_TRASH && 'trash' != $post->post_status )

		return wp_trash_post( $post_id );



	delete_post_meta($post_id, '_wp_trash_meta_status');

	delete_post_meta($post_id, '_wp_trash_meta_time');



	$meta = wp_get_attachment_metadata( $post_id );

	$backup_sizes = get_post_meta( $post->ID, '_wp_attachment_backup_sizes', true );

	$file = get_attached_file( $post_id );



	if ( is_multisite() )

		delete_transient( 'dirsize_cache' );



	do_action('delete_attachment', $post_id);



	wp_delete_object_term_relationships($post_id, array('category', 'post_tag'));

	wp_delete_object_term_relationships($post_id, get_object_taxonomies($post->post_type));



	$wpdb->query( $wpdb->prepare( "DELETE FROM $wpdb->postmeta WHERE meta_key = '_thumbnail_id' AND meta_value = %d", $post_id ));



	$comment_ids = $wpdb->get_col( $wpdb->prepare( "SELECT comment_ID FROM $wpdb->comments WHERE comment_post_ID = %d", $post_id ));

	if ( ! empty( $comment_ids ) ) {

		do_action( 'delete_comment', $comment_ids );

		foreach ( $comment_ids as $comment_id )

			wp_delete_comment( $comment_id, true );

		do_action( 'deleted_comment', $comment_ids );

	}



	$post_meta_ids = $wpdb->get_col( $wpdb->prepare( "SELECT meta_id FROM $wpdb->postmeta WHERE post_id = %d ", $post_id ));

	if ( !empty($post_meta_ids) ) {

		do_action( 'delete_postmeta', $post_meta_ids );

		$in_post_meta_ids = "'" . implode("', '", $post_meta_ids) . "'";

		$wpdb->query( "DELETE FROM $wpdb->postmeta WHERE meta_id IN($in_post_meta_ids)" );

		do_action( 'deleted_postmeta', $post_meta_ids );

	}



	do_action( 'delete_post', $post_id );

	$wpdb->query( $wpdb->prepare( "DELETE FROM $wpdb->posts WHERE ID = %d", $post_id ));

	do_action( 'deleted_post', $post_id );



	$uploadpath = wp_upload_dir();



	if ( ! empty($meta['thumb']) ) {

		// Don't delete the thumb if another attachment uses it

		if (! $wpdb->get_row( $wpdb->prepare( "SELECT meta_id FROM $wpdb->postmeta WHERE meta_key = '_wp_attachment_metadata' AND meta_value LIKE %s AND post_id <> %d", '%' . $meta['thumb'] . '%', $post_id)) ) {

			$thumbfile = str_replace(basename($file), $meta['thumb'], $file);

			$thumbfile = apply_filters('wp_delete_file', $thumbfile);

			@ unlink( path_join($uploadpath['basedir'], $thumbfile) );

		}

	}



	// remove intermediate and backup images if there are any

	foreach ( get_intermediate_image_sizes() as $size ) {

		if ( $intermediate = image_get_intermediate_size($post_id, $size) ) {

			$intermediate_file = apply_filters('wp_delete_file', $intermediate['path']);

			@ unlink( path_join($uploadpath['basedir'], $intermediate_file) );

		}

	}



	if ( is_array($backup_sizes) ) {

		foreach ( $backup_sizes as $size ) {

			$del_file = path_join( dirname($meta['file']), $size['file'] );

			$del_file = apply_filters('wp_delete_file', $del_file);

			@ unlink( path_join($uploadpath['basedir'], $del_file) );

		}

	}



	$file = apply_filters('wp_delete_file', $file);



	if ( ! empty($file) )

		@ unlink($file);



	clean_post_cache($post_id);



	return $post;

}