Walker

14#[AllowDynamicProperties]15class Walker {16	/**17	 * What the class handles.18	 *19	 * @since 2.1.020	 * @var string21	 */22	public $tree_type;23 24	/**25	 * DB fields to use.26	 *27	 * @since 2.1.028	 * @var string[]29	 */30	public $db_fields;31 32	/**33	 * Max number of pages walked by the paged walker.34	 *35	 * @since 2.7.036	 * @var int37	 */38	public $max_pages = 1;39 40	/**41	 * Whether the current element has children or not.42	 *43	 * To be used in start_el().44	 *45	 * @since 4.0.046	 * @var bool47	 */48	public $has_children;49 50	/**51	 * Starts the list before the elements are added.52	 *53	 * The $args parameter holds additional values that may be used with the child54	 * class methods. This method is called at the start of the output list.55	 *56	 * @since 2.1.057	 * @abstract58	 *59	 * @param string $output Used to append additional content (passed by reference).60	 * @param int    $depth  Depth of the item.61	 * @param array  $args   An array of additional arguments.62	 */63	public function start_lvl( &$output, $depth = 0, $args = array() ) {}64 65	/**66	 * Ends the list of after the elements are added.67	 *68	 * The $args parameter holds additional values that may be used with the child69	 * class methods. This method finishes the list at the end of output of the elements.70	 *71	 * @since 2.1.072	 * @abstract73	 *74	 * @param string $output Used to append additional content (passed by reference).75	 * @param int    $depth  Depth of the item.76	 * @param array  $args   An array of additional arguments.77	 */78	public function end_lvl( &$output, $depth = 0, $args = array() ) {}79 80	/**81	 * Starts the element output.82	 *83	 * The $args parameter holds additional values that may be used with the child84	 * class methods. Also includes the element output.85	 *86	 * @since 2.1.087	 * @since 5.9.0 Renamed `$object` (a PHP reserved keyword) to `$data_object` for PHP 8 named parameter support.88	 * @abstract89	 *90	 * @param string $output            Used to append additional content (passed by reference).91	 * @param object $data_object       The data object.92	 * @param int    $depth             Depth of the item.93	 * @param array  $args              An array of additional arguments.