public function getSortableMetaKeys() { if (!isset($_POST['posttype']) || empty($_POST['posttype'])) { echo '0'; die; } $meta = \Modularity\Helper\Post::getPosttypeMetaKeys($_POST['posttype']); $response = array('meta_keys' => $meta, 'curr' => get_field('sorted_by', $_POST['post'])); echo json_encode($response); die; }