[WordPress] Searching custom post types.

00-searching-custom-post-types.php

<?php

add_filter( 'pre_get_posts', 'acme_filter_search' );
/**
 * If the specified query is a search query, then modify the post_type array
 * to support a the 'review' custom post type.
 *
 * @since    1.0.0
 *
 * @param    object    $query    The current search query.
 * @return   object    $query    The modified query supporting CPTs.
 */
function acme_filter_search( $query ) {

	if ( ! $query->is_search ) {
		return $query;
	}

	$query->set( 'post_type', array( 'post', 'page', 'review' ) );

	return $query;

}