<?php
/**
 * Widget API: WP_Widget_Categories class
 *
 * @package WordPress
 * @subpackage Widgets
 * @since 4.4.0
 */

/**
 * Core class used to implement a Categories widget.
 *
 * @since 2.8.0
 *
 * @see WP_Widget
 */
class WP_Widget_Categories extends WP_Widget {

    /**
     * Sets up a new Categories widget instance.
     *
     * @since 2.8.0
     */
    public function __construct() {
        $widget_ops = array(
            'classname'                   => 'widget_categories',
            'description'                 => __( 'A list or dropdown of categories.' ),
            'customize_selective_refresh' => true,
            'show_instance_in_rest'       => true,
        );
        parent::__construct( 'categories', __( 'Categories' ), $widget_ops );
    }

    /**
     * Outputs the content for the current Categories widget instance.
     *
     * @since 2.8.0
     * @since 4.2.0 Creates a unique HTML ID for the `<select>` element
     *              if more than one instance is displayed on the page.
     *
     * @param array $args     Display arguments including 'before_title', 'after_title',
     *                        'before_widget', and 'after_widget'.
     * @param array $instance Settings for the current Categories widget instance.
     */
    public function widget( $args, $instance ) {
        static $first_dropdown = true;

        $default_title = __( 'Categories' );
        $title         = ! empty( $instance['title'] ) ? $instance['title'] : $default_title;

        /** This filter is documented in wp-includes/widgets/class-wp-widget-pages.php */
        $title = apply_filters( 'widget_title', $title, $instance, $this->id_base );

        $count        = ! empty( $instance['count'] ) ? '1' : '0';
        $hierarchical = ! empty( $instance['hierarchical'] ) ? '1' : '0';
        $dropdown     = ! empty( $instance['dropdown'] ) ? '1' : '0';

        echo $args['before_widget'];

        if ( $title ) {
            echo $args['before_title'] . $title . $args['after_title'];
        }

        $cat_args = array(
            'orderby'      => 'name',
            'show_count'   => $count,
            'hierarchical' => $hierarchical,
        );

        if ( $dropdown ) {
            printf( '<form action="%s" method="get">', esc_url( home_url() ) );
            $dropdown_id    = ( $first_dropdown ) ? 'cat' : "{$this->id_base}-dropdown-{$this->number}";
            $first_dropdown = false;

            echo '<label class="screen-reader-text" for="' . esc_attr( $dropdown_id ) . '">' . $title . '</label>';

            $cat_args['show_option_none'] = __( 'Select Category' );
            $cat_args['id']               = $dropdown_id;

            /**
             * Filters the arguments for the Categories widget drop-down.
             *
             * @since 2.8.0
             * @since 4.9.0 Added the `$instance` parameter.
             *
             * @see wp_dropdown_categories()
             *
             * @param array $cat_args An array of Categories widget drop-down arguments.
             * @param array $instance Array of settings for the current widget.
             */
            wp_dropdown_categories( apply_filters( 'widget_categories_dropdown_args', $cat_args, $instance ) );

            echo '</form>';

            ob_start();
            ?>

<script>
( ( dropdownId ) => {
    const dropdown = document.getElementById( dropdownId );
    function onSelectChange() {
        setTimeout( () => {
            if ( 'escape' === dropdown.dataset.lastkey ) {
                return;
            }
            if ( dropdown.value && parseInt( dropdown.value ) > 0 && dropdown instanceof HTMLSelectElement ) {
                dropdown.parentElement.submit();
            }
        }, 250 );
    }
    function onKeyUp( event ) {
        if ( 'Escape' === event.key ) {
            dropdown.dataset.lastkey = 'escape';
        } else {
            delete dropdown.dataset.lastkey;
        }
    }
    function onClick() {
        delete dropdown.dataset.lastkey;
    }
    dropdown.addEventListener( 'keyup', onKeyUp );
    dropdown.addEventListener( 'click', onClick );
    dropdown.addEventListener( 'change', onSelectChange );
})( <?php echo wp_json_encode( $dropdown_id, JSON_HEX_TAG | JSON_UNESCAPED_SLASHES ); ?> );
</script>

            <?php
            wp_print_inline_script_tag( wp_remove_surrounding_empty_script_tags( ob_get_clean() ) . "\n//# sourceURL=" . rawurlencode( __METHOD__ ) );
        } else {
            $format = current_theme_supports( 'html5', 'navigation-widgets' ) ? 'html5' : 'xhtml';

            /** This filter is documented in wp-includes/widgets/class-wp-nav-menu-widget.php */
            $format = apply_filters( 'navigation_widgets_format', $format );

            if ( 'html5' === $format ) {
                // The title may be filtered: Strip out HTML and make sure the aria-label is never empty.
                $title      = trim( strip_tags( $title ) );
                $aria_label = $title ? $title : $default_title;
                echo '<nav aria-label="' . esc_attr( $aria_label ) . '">';
            }
            ?>

            <ul>
                <?php
                $cat_args['title_li'] = '';

                /**
                 * Filters the arguments for the Categories widget.
                 *
                 * @since 2.8.0
                 * @since 4.9.0 Added the `$instance` parameter.
                 *
                 * @param array $cat_args An array of Categories widget options.
                 * @param array $instance Array of settings for the current widget.
                 */
                wp_list_categories( apply_filters( 'widget_categories_args', $cat_args, $instance ) );
                ?>
            </ul>

            <?php
            if ( 'html5' === $format ) {
                echo '</nav>';
            }
        }

        echo $args['after_widget'];
    }

    /**
     * Handles updating settings for the current Categories widget instance.
     *
     * @since 2.8.0
     *
     * @param array $new_instance New settings for this instance as input by the user via
     *                            WP_Widget::form().
     * @param array $old_instance Old settings for this instance.
     * @return array Updated settings to save.
     */
    public function update( $new_instance, $old_instance ) {
        $instance                 = $old_instance;
        $instance['title']        = sanitize_text_field( $new_instance['title'] );
        $instance['count']        = ! empty( $new_instance['count'] ) ? 1 : 0;
        $instance['hierarchical'] = ! empty( $new_instance['hierarchical'] ) ? 1 : 0;
        $instance['dropdown']     = ! empty( $new_instance['dropdown'] ) ? 1 : 0;

        return $instance;
    }

    /**
     * Outputs the settings form for the Categories widget.
     *
     * @since 2.8.0
     *
     * @param array $instance Current settings.
     */
    public function form( $instance ) {
        // Defaults.
        $instance     = wp_parse_args( (array) $instance, array( 'title' => '' ) );
        $count        = isset( $instance['count'] ) ? (bool) $instance['count'] : false;
        $hierarchical = isset( $instance['hierarchical'] ) ? (bool) $instance['hierarchical'] : false;
        $dropdown     = isset( $instance['dropdown'] ) ? (bool) $instance['dropdown'] : false;
        ?>
        <p>
            <label for="<?php echo $this->get_field_id( 'title' ); ?>"><?php _e( 'Title:' ); ?></label>
            <input class="widefat" id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" type="text" value="<?php echo esc_attr( $instance['title'] ); ?>" />
        </p>

        <p>
            <input type="checkbox" class="checkbox" id="<?php echo $this->get_field_id( 'dropdown' ); ?>" name="<?php echo $this->get_field_name( 'dropdown' ); ?>"<?php checked( $dropdown ); ?> />
            <label for="<?php echo $this->get_field_id( 'dropdown' ); ?>"><?php _e( 'Display as dropdown' ); ?></label>
            <br />

            <input type="checkbox" class="checkbox" id="<?php echo $this->get_field_id( 'count' ); ?>" name="<?php echo $this->get_field_name( 'count' ); ?>"<?php checked( $count ); ?> />
            <label for="<?php echo $this->get_field_id( 'count' ); ?>"><?php _e( 'Show post counts' ); ?></label>
            <br />

            <input type="checkbox" class="checkbox" id="<?php echo $this->get_field_id( 'hierarchical' ); ?>" name="<?php echo $this->get_field_name( 'hierarchical' ); ?>"<?php checked( $hierarchical ); ?> />
            <label for="<?php echo $this->get_field_id( 'hierarchical' ); ?>"><?php _e( 'Show hierarchy' ); ?></label>
        </p>
        <?php
    }
}