Walker_Page

17class Walker_Page extends Walker {18 19	/**20	 * What the class handles.21	 *22	 * @since 2.1.023	 * @var string24	 *25	 * @see Walker::$tree_type26	 */27	public $tree_type = 'page';28 29	/**30	 * Database fields to use.31	 *32	 * @since 2.1.033	 * @var string[]34	 *35	 * @see Walker::$db_fields36	 * @todo Decouple this.37	 */38	public $db_fields = array(39		'parent' => 'post_parent',40		'id'     => 'ID',41	);42 43	/**44	 * Outputs the beginning of the current level in the tree before elements are output.45	 *46	 * @since 2.1.047	 *48	 * @see Walker::start_lvl()49	 *50	 * @param string $output Used to append additional content (passed by reference).51	 * @param int    $depth  Optional. Depth of page. Used for padding. Default 0.52	 * @param array  $args   Optional. Arguments for outputting the next level.53	 *                       Default empty array.54	 */55	public function start_lvl( &$output, $depth = 0, $args = array() ) {56		if ( isset( $args['item_spacing'] ) && 'preserve' === $args['item_spacing'] ) {57			$t = "\t";58			$n = "\n";59		} else {60			$t = '';61			$n = '';62		}63		$indent  = str_repeat( $t, $depth );64		$output .= "{$n}{$indent}<ul class='children'>{$n}";65	}66 67	/**68	 * Outputs the end of the current level in the tree after elements are output.69	 *70	 * @since 2.1.071	 *72	 * @see Walker::end_lvl()73	 *74	 * @param string $output Used to append additional content (passed by reference).75	 * @param int    $depth  Optional. Depth of page. Used for padding. Default 0.76	 * @param array  $args   Optional. Arguments for outputting the end of the current level.77	 *                       Default empty array.78	 */79	public function end_lvl( &$output, $depth = 0, $args = array() ) {80		if ( isset( $args['item_spacing'] ) && 'preserve' === $args['item_spacing'] ) {81			$t = "\t";82			$n = "\n";83		} else {84			$t = '';85			$n = '';86		}87		$indent  = str_repeat( $t, $depth );88		$output .= "{$indent}</ul>{$n}";89	}90 91	/**92	 * Outputs the beginning of the current element in the tree.93	 *94	 * @see Walker::start_el()95	 * @since 2.1.096	 * @since 5.9.0 Renamed `$page` to `$data_object` and `$current_page` to `$current_object_id`