1<?php
  2/**
  3 * Taxonomy API: Walker_CategoryDropdown class
  4 *
  5 * @package WordPress
  6 * @subpackage Template
  7 * @since 4.4.0
  8 */
  9
 10/**
 11 * Core class used to create an HTML dropdown list of Categories.
 12 *
 13 * @since 2.1.0
 14 *
 15 * @see Walker
 16 */
 17class Walker_CategoryDropdown extends Walker {
 18
 19	/**
 20	 * What the class handles.
 21	 *
 22	 * @since 2.1.0
 23	 * @var string
 24	 *
 25	 * @see Walker::$tree_type
 26	 */
 27	public $tree_type = 'category';
 28
 29	/**
 30	 * Database fields to use.
 31	 *
 32	 * @since 2.1.0
 33	 * @todo Decouple this
 34	 * @var string[]
 35	 *
 36	 * @see Walker::$db_fields
 37	 */
 38	public $db_fields = array(
 39		'parent' => 'parent',
 40		'id'     => 'term_id',
 41	);
 42
 43	/**
 44	 * Starts the element output.
 45	 *
 46	 * @since 2.1.0
 47	 * @since 5.9.0 Renamed `$category` to `$data_object` and `$id` to `$current_object_id`
 48	 *              to match parent class for PHP 8 named parameter support.
 49	 *
 50	 * @see Walker::start_el()
 51	 *
 52	 * @param string  $output            Used to append additional content (passed by reference).
 53	 * @param WP_Term $data_object       Category data object.
 54	 * @param int     $depth             Depth of category. Used for padding.
 55	 * @param array   $args              Uses 'selected', 'show_count', and 'value_field' keys, if they exist.
 56	 *                                   See wp_dropdown_categories().
 57	 * @param int     $current_object_id Optional. ID of the current category. Default 0.
 58	 */
 59	public function start_el( &$output, $data_object, $depth = 0, $args = array(), $current_object_id = 0 ) {
 60		// Restores the more descriptive, specific name for use within this method.
 61		$category = $data_object;
 62
 63		$pad = str_repeat( '&nbsp;', $depth * 3 );
 64
 65		/** This filter is documented in wp-includes/category-template.php */
 66		$cat_name = apply_filters( 'list_cats', $category->name, $category );
 67
 68		if ( isset( $args['value_field'] ) && isset( $category->{$args['value_field']} ) ) {
 69			$value_field = $args['value_field'];
 70		} else {
 71			$value_field = 'term_id';
 72		}
 73
 74		$output .= "\t<option class=\"level-$depth\" value=\"" . esc_attr( $category->{$value_field} ) . '"';
 75
 76		// Type-juggling causes false matches, so we force everything to a string.
 77		if ( (string) $category->{$value_field} === (string) $args['selected'] ) {
 78			$output .= ' selected="selected"';
 79		}
 80		$output .= '>';
 81		$output .= $pad . $cat_name;
 82		if ( $args['show_count'] ) {
 83			$output .= '&nbsp;&nbsp;(' . number_format_i18n( $category->count ) . ')';
 84		}
 85		$output .= "</option>\n";
 86	}
 87}
 88