<?php

/**

 * Taxonomy API: Walker_CategoryDropdown class

 *

 * @package WordPress

 * @subpackage Template

 * @since 4.4.0

 */

/**

 * Core class used to create an HTML dropdown list of Categories.

 *

 * @since 2.1.0

 *

 * @see Walker

 */

class Walker_CategoryDropdown 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

	 * @todo Decouple this

	 * @var string[]

	 *

	 * @see Walker::$db_fields

	 */

	public $db_fields = array(

		'parent' => 'parent',

		'id'     => 'term_id',

	);

	/**

	 * Starts the element output.

	 *

	 * @since 2.1.0

	 * @since 5.9.0 Renamed `$category` to `$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_Term $data_object       Category data object.

	 * @param int     $depth             Depth of category. Used for padding.

	 * @param array   $args              Uses 'selected', 'show_count', and 'value_field' keys, if they exist.

	 *                                   See wp_dropdown_categories().

	 * @param int     $current_object_id Optional. ID of the current category. 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.

		$category = $data_object;

		$pad = str_repeat( ' ', $depth * 3 );

		/** This filter is documented in wp-includes/category-template.php */

		$cat_name = apply_filters( 'list_cats', $category->name, $category );

		if ( isset( $args['value_field'] ) && isset( $category->{$args['value_field']} ) ) {

			$value_field = $args['value_field'];

		} else {

			$value_field = 'term_id';

		}

		$output .= "\t<option class=\"level-$depth\" value=\"" . esc_attr( $category->{$value_field} ) . '"';

		// Type-juggling causes false matches, so we force everything to a string.

		if ( (string) $category->{$value_field} === (string) $args['selected'] ) {

			$output .= ' selected="selected"';

		}

		$output .= '>';

		$output .= $pad . $cat_name;

		if ( $args['show_count'] ) {

			$output .= '  (' . number_format_i18n( $category->count ) . ')';

		}

		$output .= "</option>\n";

	}

}