<?php

/**

 * Nav Menu API: Walker_Nav_Menu class

 *

 * @package WordPress

 * @subpackage Nav_Menus

 * @since 4.6.0

 */

/**

 * Core class used to implement an HTML list of nav menu items.

 *

 * @since 3.0.0

 *

 * @see Walker

 */

class Walker_Nav_Menu extends Walker {

	/**

	 * What the class handles.

	 *

	 * @since 3.0.0

	 * @var string

	 *

	 * @see Walker::$tree_type

	 */

	public $tree_type = array( 'post_type', 'taxonomy', 'custom' );

	/**

	 * Database fields to use.

	 *

	 * @since 3.0.0

	 * @todo Decouple this.

	 * @var string[]

	 *

	 * @see Walker::$db_fields

	 */

	public $db_fields = array(

		'parent' => 'menu_item_parent',

		'id'     => 'db_id',

	);

	/**

	 * The URL to the privacy policy page.

	 *

	 * @since 6.8.0

	 * @var string

	 */

	private $privacy_policy_url;

	/**

	 * Constructor.

	 *

	 * @since 6.8.0

	 */

	public function __construct() {

		$this->privacy_policy_url = get_privacy_policy_url();

	}

	/**

	 * Starts the list before the elements are added.

	 *

	 * @since 3.0.0

	 *

	 * @see Walker::start_lvl()

	 *

	 * @param string   $output Used to append additional content (passed by reference).

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

	 * @param stdClass $args   An object of wp_nav_menu() arguments.

	 */

	public function start_lvl( &$output, $depth = 0, $args = null ) {

		if ( isset( $args->item_spacing ) && 'discard' === $args->item_spacing ) {

			$t = '';

			$n = '';

		} else {

			$t = "\t";

			$n = "\n";

		}

		$indent = str_repeat( $t, $depth );

		// Default class.

		$classes = array( 'sub-menu' );

		/**

		 * Filters the CSS class(es) applied to a menu list element.

		 *

		 * @since 4.8.0

		 *

		 * @param string[] $classes Array of the CSS classes that are applied to the menu `<ul>` element.

		 * @param stdClass $args    An object of `wp_nav_menu()` arguments.

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

		 */

		$class_names = implode( ' ', apply_filters( 'nav_menu_submenu_css_class', $classes, $args, $depth ) );

		$atts          = array();

		$atts['class'] = ! empty( $class_names ) ? $class_names : '';

		/**

		 * Filters the HTML attributes applied to a menu list element.

		 *

		 * @since 6.3.0

		 *

		 * @param array $atts {

		 *     The HTML attributes applied to the `<ul>` element, empty strings are ignored.

		 *

		 *     @type string $class    HTML CSS class attribute.

		 * }

		 * @param stdClass $args      An object of `wp_nav_menu()` arguments.

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

		 */

		$atts       = apply_filters( 'nav_menu_submenu_attributes', $atts, $args, $depth );

		$attributes = $this->build_atts( $atts );

		$output .= "{$n}{$indent}<ul{$attributes}>{$n}";

	}

	/**

	 * Ends the list of after the elements are added.

	 *

	 * @since 3.0.0

	 *

	 * @see Walker::end_lvl()

	 *

	 * @param string   $output Used to append additional content (passed by reference).

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

	 * @param stdClass $args   An object of wp_nav_menu() arguments.

	 */

	public function end_lvl( &$output, $depth = 0, $args = null ) {

		if ( isset( $args->item_spacing ) && 'discard' === $args->item_spacing ) {

			$t = '';

			$n = '';

		} else {

			$t = "\t";

			$n = "\n";

		}

		$indent  = str_repeat( $t, $depth );

		$output .= "$indent</ul>{$n}";

	}

	/**

	 * Starts the element output.

	 *

	 * @since 3.0.0

	 * @since 4.4.0 The {@see 'nav_menu_item_args'} filter was added.

	 * @since 5.9.0 Renamed `$item` to `$data_object` and `$id` to `$current_object_id`

	 *              to match parent class for PHP 8 named parameter support.

	 * @since 6.7.0 Removed redundant title attributes.

	 *

	 * @see Walker::start_el()

	 *

	 * @param string   $output            Used to append additional content (passed by reference).

	 * @param WP_Post  $data_object       Menu item data object.

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

	 * @param stdClass $args              An object of wp_nav_menu() arguments.

	 * @param int      $current_object_id Optional. ID of the current menu item. Default 0.

	 */

	public function start_el( &$output, $data_object, $depth = 0, $args = null, $current_object_id = 0 ) {

		// Restores the more descriptive, specific name for use within this method.

		$menu_item = $data_object;

		if ( isset( $args->item_spacing ) && 'discard' === $args->item_spacing ) {

			$t = '';

			$n = '';

		} else {

			$t = "\t";

			$n = "\n";

		}

		$indent = ( $depth ) ? str_repeat( $t, $depth ) : '';

		$classes   = empty( $menu_item->classes ) ? array() : (array) $menu_item->classes;

		$classes[] = 'menu-item-' . $menu_item->ID;

		/**

		 * Filters the arguments for a single nav menu item.

		 *

		 * @since 4.4.0

		 *

		 * @param stdClass $args      An object of wp_nav_menu() arguments.

		 * @param WP_Post  $menu_item Menu item data object.

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

		 */

		$args = apply_filters( 'nav_menu_item_args', $args, $menu_item, $depth );

		/**

		 * Filters the CSS classes applied to a menu item's list item element.

		 *

		 * @since 3.0.0

		 * @since 4.1.0 The `$depth` parameter was added.

		 *

		 * @param string[] $classes   Array of the CSS classes that are applied to the menu item's `<li>` element.

		 * @param WP_Post  $menu_item The current menu item object.

		 * @param stdClass $args      An object of wp_nav_menu() arguments.

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

		 */

		$class_names = implode( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $menu_item, $args, $depth ) );

		/**

		 * Filters the ID attribute applied to a menu item's list item element.

		 *

		 * @since 3.0.1

		 * @since 4.1.0 The `$depth` parameter was added.

		 *

		 * @param string   $menu_item_id The ID attribute applied to the menu item's `<li>` element.

		 * @param WP_Post  $menu_item    The current menu item.

		 * @param stdClass $args         An object of wp_nav_menu() arguments.

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

		 */

		$id = apply_filters( 'nav_menu_item_id', 'menu-item-' . $menu_item->ID, $menu_item, $args, $depth );

		$li_atts          = array();

		$li_atts['id']    = ! empty( $id ) ? $id : '';

		$li_atts['class'] = ! empty( $class_names ) ? $class_names : '';

		/**

		 * Filters the HTML attributes applied to a menu's list item element.

		 *

		 * @since 6.3.0

		 *

		 * @param array $li_atts {

		 *     The HTML attributes applied to the menu item's `<li>` element, empty strings are ignored.

		 *

		 *     @type string $class        HTML CSS class attribute.

		 *     @type string $id           HTML id attribute.

		 * }

		 * @param WP_Post  $menu_item The current menu item object.

		 * @param stdClass $args      An object of wp_nav_menu() arguments.

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

		 */

		$li_atts       = apply_filters( 'nav_menu_item_attributes', $li_atts, $menu_item, $args, $depth );

		$li_attributes = $this->build_atts( $li_atts );

		$output .= $indent . '<li' . $li_attributes . '>';

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

		$title = apply_filters( 'the_title', $menu_item->title, $menu_item->ID );

		// Save filtered value before filtering again.

		$the_title_filtered = $title;

		/**

		 * Filters a menu item's title.

		 *

		 * @since 4.4.0

		 *

		 * @param string   $title     The menu item's title.

		 * @param WP_Post  $menu_item The current menu item object.

		 * @param stdClass $args      An object of wp_nav_menu() arguments.

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

		 */

		$title = apply_filters( 'nav_menu_item_title', $title, $menu_item, $args, $depth );

		$atts           = array();

		$atts['target'] = ! empty( $menu_item->target ) ? $menu_item->target : '';

		$atts['rel']    = ! empty( $menu_item->xfn ) ? $menu_item->xfn : '';

		if ( ! empty( $menu_item->url ) ) {

			if ( $this->privacy_policy_url === $menu_item->url ) {

				$atts['rel'] = empty( $atts['rel'] ) ? 'privacy-policy' : $atts['rel'] . ' privacy-policy';

			}

			$atts['href'] = $menu_item->url;

		} else {

			$atts['href'] = '';

		}

		$atts['aria-current'] = $menu_item->current ? 'page' : '';

		// Add title attribute only if it does not match the link text (before or after filtering).

		if ( ! empty( $menu_item->attr_title )

			&& trim( strtolower( $menu_item->attr_title ) ) !== trim( strtolower( $menu_item->title ) )

			&& trim( strtolower( $menu_item->attr_title ) ) !== trim( strtolower( $the_title_filtered ) )

			&& trim( strtolower( $menu_item->attr_title ) ) !== trim( strtolower( $title ) )

		) {

			$atts['title'] = $menu_item->attr_title;

		} else {

			$atts['title'] = '';

		}

		/**

		 * Filters the HTML attributes applied to a menu item's anchor element.

		 *

		 * @since 3.6.0

		 * @since 4.1.0 The `$depth` parameter was added.

		 *

		 * @param array $atts {

		 *     The HTML attributes applied to the menu item's `<a>` element, empty strings are ignored.

		 *

		 *     @type string $title        Title attribute.

		 *     @type string $target       Target attribute.

		 *     @type string $rel          The rel attribute.

		 *     @type string $href         The href attribute.

		 *     @type string $aria-current The aria-current attribute.

		 * }

		 * @param WP_Post  $menu_item The current menu item object.

		 * @param stdClass $args      An object of wp_nav_menu() arguments.

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

		 */

		$atts       = apply_filters( 'nav_menu_link_attributes', $atts, $menu_item, $args, $depth );

		$attributes = $this->build_atts( $atts );

		$item_output  = $args->before;

		$item_output .= '<a' . $attributes . '>';

		$item_output .= $args->link_before . $title . $args->link_after;

		$item_output .= '</a>';

		$item_output .= $args->after;

		/**

		 * Filters a menu item's starting output.

		 *

		 * The menu item's starting output only includes `$args->before`, the opening `<a>`,

		 * the menu item's title, the closing `</a>`, and `$args->after`. Currently, there is

		 * no filter for modifying the opening and closing `<li>` for a menu item.

		 *

		 * @since 3.0.0

		 *

		 * @param string   $item_output The menu item's starting HTML output.

		 * @param WP_Post  $menu_item   Menu item data object.

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

		 * @param stdClass $args        An object of wp_nav_menu() arguments.

		 */

		$output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $menu_item, $depth, $args );

	}

	/**

	 * Ends the element output, if needed.

	 *

	 * @since 3.0.0

	 * @since 5.9.0 Renamed `$item` to `$data_object` to match parent class for PHP 8 named parameter support.

	 *

	 * @see Walker::end_el()

	 *

	 * @param string   $output      Used to append additional content (passed by reference).

	 * @param WP_Post  $data_object Menu item data object. Not used.

	 * @param int      $depth       Depth of page. Not Used.

	 * @param stdClass $args        An object of wp_nav_menu() arguments.

	 */

	public function end_el( &$output, $data_object, $depth = 0, $args = null ) {

		if ( isset( $args->item_spacing ) && 'discard' === $args->item_spacing ) {

			$t = '';

			$n = '';

		} else {

			$t = "\t";

			$n = "\n";

		}

		$output .= "</li>{$n}";

	}

	/**

	 * Builds a string of HTML attributes from an array of key/value pairs.

	 * Empty values are ignored.

	 *

	 * @since 6.3.0

	 *

	 * @param  array $atts Optional. An array of HTML attribute key/value pairs. Default empty array.

	 * @return string A string of HTML attributes.

	 */

	protected function build_atts( $atts = array() ) {

		$attribute_string = '';

		foreach ( $atts as $attr => $value ) {

			if ( false !== $value && '' !== $value && is_scalar( $value ) ) {

				$value             = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );

				$attribute_string .= ' ' . $attr . '="' . $value . '"';

			}

		}

		return $attribute_string;

	}

}