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( ' ', $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 .= ' (' . number_format_i18n( $category->count ) . ')';
84 }
85 $output .= "</option>\n";
86 }
87}
88