/** * Taxonomy API: Walker_Category class * * @package WordPress * @subpackage Template * @since 4.4.0 */ /** * Core class used to create an HTML list of categories. * * @since 2.1.0 * * @see Walker */ class Walker_Category extends Walker { /** * What the class handles. * * @since 2.1.0 * @var string * * @see Walker::$tree_type */ public $tree_type = 'category'; /** * Database fields to use. * * @since 2.1.0 * @var string[] * * @see Walker::$db_fields * @todo Decouple this */ public $db_fields = array( 'parent' => 'parent', 'id' => 'term_id', ); /** * Starts the list before the elements are added. * * @since 2.1.0 * * @see Walker::start_lvl() * * @param string $output Used to append additional content. Passed by reference. * @param int $depth Optional. Depth of category. Used for tab indentation. Default 0. * @param array $args Optional. An array of arguments. Will only append content if style argument * value is 'list'. See wp_list_categories(). Default empty array. */ public function start_lvl( &$output, $depth = 0, $args = array() ) { if ( 'list' !== $args['style'] ) { return; } $indent = str_repeat( "\t", $depth ); $output .= "$indent