name : class-walker-page-dropdown.php <?php /** * Post API: Walker_PageDropdown class * * @package WordPress * @subpackage Post * @since 4.4.0 */ /** * Core class used to create an HTML drop-down list of pages. * * @since 2.1.0 * * @see Walker */ class Walker_PageDropdown extends Walker { /** * What the class handles. * * @since 2.1.0 * @var string * * @see Walker::$tree_type */ public $tree_type = 'page'; /** * Database fields to use. * * @since 2.1.0 * @var string[] * * @see Walker::$db_fields * @todo Decouple this */ public $db_fields = array( 'parent' => 'post_parent', 'id' => 'ID', ); /** * Starts the element output. * * @since 2.1.0 * @since 5.9.0 Renamed `$page` to `$data_object` and `$id` to `$current_object_id` * to match parent class for PHP 8 named parameter support. * * @see Walker::start_el() * * @param string $output Used to append additional content. Passed by reference. * @param WP_Post $data_object Page data object. * @param int $depth Optional. Depth of page in reference to parent pages. * Used for padding. Default 0. * @param array $args Optional. Uses 'selected' argument for selected page to * set selected HTML attribute for option element. Uses * 'value_field' argument to fill "value" attribute. * See wp_dropdown_pages(). Default empty array. * @param int $current_object_id Optional. ID of the current page. Default 0. */ public function start_el( &$output, $data_object, $depth = 0, $args = array(), $current_object_id = 0 ) { // Restores the more descriptive, specific name for use within this method. $page = $data_object; $pad = str_repeat( '&nbsp;', $depth * 3 ); if ( ! isset( $args['value_field'] ) || ! isset( $page->{$args['value_field']} ) ) { $args['value_field'] = 'ID'; } $output .= "\t<option class=\"level-$depth\" value=\"" . esc_attr( $page->{$args['value_field']} ) . '"'; if ( $page->ID === (int) $args['selected'] ) { $output .= ' selected="selected"'; } $output .= '>'; $title = $page->post_title; if ( '' === $title ) { /* translators: %d: ID of a post. */ $title = sprintf( __( '#%d (no title)' ), $page->ID ); } /** * Filters the page title when creating an HTML drop-down list of pages. * * @since 3.1.0 * * @param string $title Page title. * @param WP_Post $page Page data object. */ $title = apply_filters( 'list_pages', $title, $page ); $output .= $pad . esc_html( $title ); $output .= "</option>\n"; } }