3 * Navigation Menu template functions
6 * @subpackage Nav_Menus
11 * Create HTML list of nav menu items.
16 class Walker_Nav_Menu extends Walker {
18 * What the class handles.
20 * @see Walker::$tree_type
24 public $tree_type = array( 'post_type', 'taxonomy', 'custom' );
27 * Database fields to use.
29 * @see Walker::$db_fields
31 * @todo Decouple this.
34 public $db_fields = array( 'parent' => 'menu_item_parent', 'id' => 'db_id' );
37 * Starts the list before the elements are added.
39 * @see Walker::start_lvl()
43 * @param string $output Passed by reference. Used to append additional content.
44 * @param int $depth Depth of menu item. Used for padding.
45 * @param array $args An array of arguments. @see wp_nav_menu()
47 public function start_lvl( &$output, $depth = 0, $args = array() ) {
48 $indent = str_repeat("\t", $depth);
49 $output .= "\n$indent<ul class=\"sub-menu\">\n";
53 * Ends the list of after the elements are added.
55 * @see Walker::end_lvl()
59 * @param string $output Passed by reference. Used to append additional content.
60 * @param int $depth Depth of menu item. Used for padding.
61 * @param array $args An array of arguments. @see wp_nav_menu()
63 public function end_lvl( &$output, $depth = 0, $args = array() ) {
64 $indent = str_repeat("\t", $depth);
65 $output .= "$indent</ul>\n";
69 * Start the element output.
71 * @see Walker::start_el()
75 * @param string $output Passed by reference. Used to append additional content.
76 * @param object $item Menu item data object.
77 * @param int $depth Depth of menu item. Used for padding.
78 * @param array $args An array of arguments. @see wp_nav_menu()
79 * @param int $id Current item ID.
81 public function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
82 $indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';
84 $classes = empty( $item->classes ) ? array() : (array) $item->classes;
85 $classes[] = 'menu-item-' . $item->ID;
88 * Filter the CSS class(es) applied to a menu item's list item element.
91 * @since 4.1.0 The `$depth` parameter was added.
93 * @param array $classes The CSS classes that are applied to the menu item's `<li>` element.
94 * @param object $item The current menu item.
95 * @param array $args An array of {@see wp_nav_menu()} arguments.
96 * @param int $depth Depth of menu item. Used for padding.
98 $class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args, $depth ) );
99 $class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';
102 * Filter the ID applied to a menu item's list item element.
105 * @since 4.1.0 The `$depth` parameter was added.
107 * @param string $menu_id The ID that is applied to the menu item's `<li>` element.
108 * @param object $item The current menu item.
109 * @param array $args An array of {@see wp_nav_menu()} arguments.
110 * @param int $depth Depth of menu item. Used for padding.
112 $id = apply_filters( 'nav_menu_item_id', 'menu-item-'. $item->ID, $item, $args, $depth );
113 $id = $id ? ' id="' . esc_attr( $id ) . '"' : '';
115 $output .= $indent . '<li' . $id . $class_names .'>';
118 $atts['title'] = ! empty( $item->attr_title ) ? $item->attr_title : '';
119 $atts['target'] = ! empty( $item->target ) ? $item->target : '';
120 $atts['rel'] = ! empty( $item->xfn ) ? $item->xfn : '';
121 $atts['href'] = ! empty( $item->url ) ? $item->url : '';
124 * Filter the HTML attributes applied to a menu item's anchor element.
127 * @since 4.1.0 The `$depth` parameter was added.
129 * @param array $atts {
130 * The HTML attributes applied to the menu item's `<a>` element, empty strings are ignored.
132 * @type string $title Title attribute.
133 * @type string $target Target attribute.
134 * @type string $rel The rel attribute.
135 * @type string $href The href attribute.
137 * @param object $item The current menu item.
138 * @param array $args An array of {@see wp_nav_menu()} arguments.
139 * @param int $depth Depth of menu item. Used for padding.
141 $atts = apply_filters( 'nav_menu_link_attributes', $atts, $item, $args, $depth );
144 foreach ( $atts as $attr => $value ) {
145 if ( ! empty( $value ) ) {
146 $value = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );
147 $attributes .= ' ' . $attr . '="' . $value . '"';
151 $item_output = $args->before;
152 $item_output .= '<a'. $attributes .'>';
153 /** This filter is documented in wp-includes/post-template.php */
154 $item_output .= $args->link_before . apply_filters( 'the_title', $item->title, $item->ID ) . $args->link_after;
155 $item_output .= '</a>';
156 $item_output .= $args->after;
159 * Filter a menu item's starting output.
161 * The menu item's starting output only includes `$args->before`, the opening `<a>`,
162 * the menu item's title, the closing `</a>`, and `$args->after`. Currently, there is
163 * no filter for modifying the opening and closing `<li>` for a menu item.
167 * @param string $item_output The menu item's starting HTML output.
168 * @param object $item Menu item data object.
169 * @param int $depth Depth of menu item. Used for padding.
170 * @param array $args An array of {@see wp_nav_menu()} arguments.
172 $output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
176 * Ends the element output, if needed.
178 * @see Walker::end_el()
182 * @param string $output Passed by reference. Used to append additional content.
183 * @param object $item Page data object. Not used.
184 * @param int $depth Depth of page. Not Used.
185 * @param array $args An array of arguments. @see wp_nav_menu()
187 public function end_el( &$output, $item, $depth = 0, $args = array() ) {
188 $output .= "</li>\n";
194 * Displays a navigation menu.
198 * @param array $args {
199 * Optional. Array of nav menu arguments.
201 * @type string $menu Desired menu. Accepts (matching in order) id, slug, name. Default empty.
202 * @type string $menu_class CSS class to use for the ul element which forms the menu. Default 'menu'.
203 * @type string $menu_id The ID that is applied to the ul element which forms the menu.
204 * Default is the menu slug, incremented.
205 * @type string $container Whether to wrap the ul, and what to wrap it with. Default 'div'.
206 * @type string $container_class Class that is applied to the container. Default 'menu-{menu slug}-container'.
207 * @type string $container_id The ID that is applied to the container. Default empty.
208 * @type callback|bool $fallback_cb If the menu doesn't exists, a callback function will fire.
209 * Default is 'wp_page_menu'. Set to false for no fallback.
210 * @type string $before Text before the link text. Default empty.
211 * @type string $after Text after the link text. Default empty.
212 * @type string $link_before Text before the link. Default empty.
213 * @type string $link_after Text after the link. Default empty.
214 * @type bool $echo Whether to echo the menu or return it. Default true.
215 * @type int $depth How many levels of the hierarchy are to be included. 0 means all. Default 0.
216 * @type object $walker Instance of a custom walker class. Default empty.
217 * @type string $theme_location Theme location to be used. Must be registered with register_nav_menu()
218 * in order to be selectable by the user.
219 * @type string $items_wrap How the list items should be wrapped. Default is a ul with an id and class.
220 * Uses printf() format with numbered placeholders.
222 * @return mixed Menu output if $echo is false, false if there are no items or no menu was found.
224 function wp_nav_menu( $args = array() ) {
225 static $menu_id_slugs = array();
227 $defaults = array( 'menu' => '', 'container' => 'div', 'container_class' => '', 'container_id' => '', 'menu_class' => 'menu', 'menu_id' => '',
228 'echo' => true, 'fallback_cb' => 'wp_page_menu', 'before' => '', 'after' => '', 'link_before' => '', 'link_after' => '', 'items_wrap' => '<ul id="%1$s" class="%2$s">%3$s</ul>',
229 'depth' => 0, 'walker' => '', 'theme_location' => '' );
231 $args = wp_parse_args( $args, $defaults );
233 * Filter the arguments used to display a navigation menu.
239 * @param array $args Array of wp_nav_menu() arguments.
241 $args = apply_filters( 'wp_nav_menu_args', $args );
242 $args = (object) $args;
245 * Filter whether to short-circuit the wp_nav_menu() output.
247 * Returning a non-null value to the filter will short-circuit
248 * wp_nav_menu(), echoing that value if $args->echo is true,
249 * returning that value otherwise.
255 * @param string|null $output Nav menu output to short-circuit with. Default null.
256 * @param object $args An object containing wp_nav_menu() arguments.
258 $nav_menu = apply_filters( 'pre_wp_nav_menu', null, $args );
260 if ( null !== $nav_menu ) {
269 // Get the nav menu based on the requested menu
270 $menu = wp_get_nav_menu_object( $args->menu );
272 // Get the nav menu based on the theme_location
273 if ( ! $menu && $args->theme_location && ( $locations = get_nav_menu_locations() ) && isset( $locations[ $args->theme_location ] ) )
274 $menu = wp_get_nav_menu_object( $locations[ $args->theme_location ] );
276 // get the first menu that has items if we still can't find a menu
277 if ( ! $menu && !$args->theme_location ) {
278 $menus = wp_get_nav_menus();
279 foreach ( $menus as $menu_maybe ) {
280 if ( $menu_items = wp_get_nav_menu_items( $menu_maybe->term_id, array( 'update_post_term_cache' => false ) ) ) {
287 // If the menu exists, get its items.
288 if ( $menu && ! is_wp_error($menu) && !isset($menu_items) )
289 $menu_items = wp_get_nav_menu_items( $menu->term_id, array( 'update_post_term_cache' => false ) );
292 * If no menu was found:
293 * - Fall back (if one was specified), or bail.
295 * If no menu items were found:
296 * - Fall back, but only if no theme location was specified.
299 if ( ( !$menu || is_wp_error($menu) || ( isset($menu_items) && empty($menu_items) && !$args->theme_location ) )
300 && $args->fallback_cb && is_callable( $args->fallback_cb ) )
301 return call_user_func( $args->fallback_cb, (array) $args );
303 if ( ! $menu || is_wp_error( $menu ) )
306 $nav_menu = $items = '';
308 $show_container = false;
309 if ( $args->container ) {
311 * Filter the list of HTML tags that are valid for use as menu containers.
315 * @param array $tags The acceptable HTML tags for use as menu containers.
316 * Default is array containing 'div' and 'nav'.
318 $allowed_tags = apply_filters( 'wp_nav_menu_container_allowedtags', array( 'div', 'nav' ) );
319 if ( in_array( $args->container, $allowed_tags ) ) {
320 $show_container = true;
321 $class = $args->container_class ? ' class="' . esc_attr( $args->container_class ) . '"' : ' class="menu-'. $menu->slug .'-container"';
322 $id = $args->container_id ? ' id="' . esc_attr( $args->container_id ) . '"' : '';
323 $nav_menu .= '<'. $args->container . $id . $class . '>';
327 // Set up the $menu_item variables
328 _wp_menu_item_classes_by_context( $menu_items );
330 $sorted_menu_items = $menu_items_with_children = array();
331 foreach ( (array) $menu_items as $menu_item ) {
332 $sorted_menu_items[ $menu_item->menu_order ] = $menu_item;
333 if ( $menu_item->menu_item_parent )
334 $menu_items_with_children[ $menu_item->menu_item_parent ] = true;
337 // Add the menu-item-has-children class where applicable
338 if ( $menu_items_with_children ) {
339 foreach ( $sorted_menu_items as &$menu_item ) {
340 if ( isset( $menu_items_with_children[ $menu_item->ID ] ) )
341 $menu_item->classes[] = 'menu-item-has-children';
345 unset( $menu_items, $menu_item );
348 * Filter the sorted list of menu item objects before generating the menu's HTML.
352 * @param array $sorted_menu_items The menu items, sorted by each menu item's menu order.
353 * @param object $args An object containing wp_nav_menu() arguments.
355 $sorted_menu_items = apply_filters( 'wp_nav_menu_objects', $sorted_menu_items, $args );
357 $items .= walk_nav_menu_tree( $sorted_menu_items, $args->depth, $args );
358 unset($sorted_menu_items);
361 if ( ! empty( $args->menu_id ) ) {
362 $wrap_id = $args->menu_id;
364 $wrap_id = 'menu-' . $menu->slug;
365 while ( in_array( $wrap_id, $menu_id_slugs ) ) {
366 if ( preg_match( '#-(\d+)$#', $wrap_id, $matches ) )
367 $wrap_id = preg_replace('#-(\d+)$#', '-' . ++$matches[1], $wrap_id );
369 $wrap_id = $wrap_id . '-1';
372 $menu_id_slugs[] = $wrap_id;
374 $wrap_class = $args->menu_class ? $args->menu_class : '';
377 * Filter the HTML list content for navigation menus.
383 * @param string $items The HTML list content for the menu items.
384 * @param object $args An object containing wp_nav_menu() arguments.
386 $items = apply_filters( 'wp_nav_menu_items', $items, $args );
388 * Filter the HTML list content for a specific navigation menu.
394 * @param string $items The HTML list content for the menu items.
395 * @param object $args An object containing wp_nav_menu() arguments.
397 $items = apply_filters( "wp_nav_menu_{$menu->slug}_items", $items, $args );
399 // Don't print any markup if there are no items at this point.
400 if ( empty( $items ) )
403 $nav_menu .= sprintf( $args->items_wrap, esc_attr( $wrap_id ), esc_attr( $wrap_class ), $items );
406 if ( $show_container )
407 $nav_menu .= '</' . $args->container . '>';
410 * Filter the HTML content for navigation menus.
416 * @param string $nav_menu The HTML content for the navigation menu.
417 * @param object $args An object containing wp_nav_menu() arguments.
419 $nav_menu = apply_filters( 'wp_nav_menu', $nav_menu, $args );
428 * Add the class property classes for the current context, if applicable.
433 * @param array $menu_items The current menu item objects to which to add the class property information.
435 function _wp_menu_item_classes_by_context( &$menu_items ) {
436 global $wp_query, $wp_rewrite;
438 $queried_object = $wp_query->get_queried_object();
439 $queried_object_id = (int) $wp_query->queried_object_id;
442 $active_ancestor_item_ids = array();
443 $active_parent_item_ids = array();
444 $active_parent_object_ids = array();
445 $possible_taxonomy_ancestors = array();
446 $possible_object_parents = array();
447 $home_page_id = (int) get_option( 'page_for_posts' );
449 if ( $wp_query->is_singular && ! empty( $queried_object->post_type ) && ! is_post_type_hierarchical( $queried_object->post_type ) ) {
450 foreach ( (array) get_object_taxonomies( $queried_object->post_type ) as $taxonomy ) {
451 if ( is_taxonomy_hierarchical( $taxonomy ) ) {
452 $term_hierarchy = _get_term_hierarchy( $taxonomy );
453 $terms = wp_get_object_terms( $queried_object_id, $taxonomy, array( 'fields' => 'ids' ) );
454 if ( is_array( $terms ) ) {
455 $possible_object_parents = array_merge( $possible_object_parents, $terms );
456 $term_to_ancestor = array();
457 foreach ( (array) $term_hierarchy as $anc => $descs ) {
458 foreach ( (array) $descs as $desc )
459 $term_to_ancestor[ $desc ] = $anc;
462 foreach ( $terms as $desc ) {
464 $possible_taxonomy_ancestors[ $taxonomy ][] = $desc;
465 if ( isset( $term_to_ancestor[ $desc ] ) ) {
466 $_desc = $term_to_ancestor[ $desc ];
467 unset( $term_to_ancestor[ $desc ] );
472 } while ( ! empty( $desc ) );
477 } elseif ( ! empty( $queried_object->taxonomy ) && is_taxonomy_hierarchical( $queried_object->taxonomy ) ) {
478 $term_hierarchy = _get_term_hierarchy( $queried_object->taxonomy );
479 $term_to_ancestor = array();
480 foreach ( (array) $term_hierarchy as $anc => $descs ) {
481 foreach ( (array) $descs as $desc )
482 $term_to_ancestor[ $desc ] = $anc;
484 $desc = $queried_object->term_id;
486 $possible_taxonomy_ancestors[ $queried_object->taxonomy ][] = $desc;
487 if ( isset( $term_to_ancestor[ $desc ] ) ) {
488 $_desc = $term_to_ancestor[ $desc ];
489 unset( $term_to_ancestor[ $desc ] );
494 } while ( ! empty( $desc ) );
497 $possible_object_parents = array_filter( $possible_object_parents );
499 $front_page_url = home_url();
501 foreach ( (array) $menu_items as $key => $menu_item ) {
503 $menu_items[$key]->current = false;
505 $classes = (array) $menu_item->classes;
506 $classes[] = 'menu-item';
507 $classes[] = 'menu-item-type-' . $menu_item->type;
508 $classes[] = 'menu-item-object-' . $menu_item->object;
510 // if the menu item corresponds to a taxonomy term for the currently-queried non-hierarchical post object
511 if ( $wp_query->is_singular && 'taxonomy' == $menu_item->type && in_array( $menu_item->object_id, $possible_object_parents ) ) {
512 $active_parent_object_ids[] = (int) $menu_item->object_id;
513 $active_parent_item_ids[] = (int) $menu_item->db_id;
514 $active_object = $queried_object->post_type;
516 // if the menu item corresponds to the currently-queried post or taxonomy object
518 $menu_item->object_id == $queried_object_id &&
520 ( ! empty( $home_page_id ) && 'post_type' == $menu_item->type && $wp_query->is_home && $home_page_id == $menu_item->object_id ) ||
521 ( 'post_type' == $menu_item->type && $wp_query->is_singular ) ||
522 ( 'taxonomy' == $menu_item->type && ( $wp_query->is_category || $wp_query->is_tag || $wp_query->is_tax ) && $queried_object->taxonomy == $menu_item->object )
525 $classes[] = 'current-menu-item';
526 $menu_items[$key]->current = true;
527 $_anc_id = (int) $menu_item->db_id;
530 ( $_anc_id = get_post_meta( $_anc_id, '_menu_item_menu_item_parent', true ) ) &&
531 ! in_array( $_anc_id, $active_ancestor_item_ids )
533 $active_ancestor_item_ids[] = $_anc_id;
536 if ( 'post_type' == $menu_item->type && 'page' == $menu_item->object ) {
537 // Back compat classes for pages to match wp_page_menu()
538 $classes[] = 'page_item';
539 $classes[] = 'page-item-' . $menu_item->object_id;
540 $classes[] = 'current_page_item';
542 $active_parent_item_ids[] = (int) $menu_item->menu_item_parent;
543 $active_parent_object_ids[] = (int) $menu_item->post_parent;
544 $active_object = $menu_item->object;
546 // if the menu item corresponds to the currently-requested URL
547 } elseif ( 'custom' == $menu_item->object ) {
548 $_root_relative_current = untrailingslashit( $_SERVER['REQUEST_URI'] );
549 $current_url = set_url_scheme( 'http://' . $_SERVER['HTTP_HOST'] . $_root_relative_current );
550 $raw_item_url = strpos( $menu_item->url, '#' ) ? substr( $menu_item->url, 0, strpos( $menu_item->url, '#' ) ) : $menu_item->url;
551 $item_url = untrailingslashit( $raw_item_url );
552 $_indexless_current = untrailingslashit( preg_replace( '/' . preg_quote( $wp_rewrite->index, '/' ) . '$/', '', $current_url ) );
554 if ( $raw_item_url && in_array( $item_url, array( $current_url, $_indexless_current, $_root_relative_current ) ) ) {
555 $classes[] = 'current-menu-item';
556 $menu_items[$key]->current = true;
557 $_anc_id = (int) $menu_item->db_id;
560 ( $_anc_id = get_post_meta( $_anc_id, '_menu_item_menu_item_parent', true ) ) &&
561 ! in_array( $_anc_id, $active_ancestor_item_ids )
563 $active_ancestor_item_ids[] = $_anc_id;
566 if ( in_array( home_url(), array( untrailingslashit( $current_url ), untrailingslashit( $_indexless_current ) ) ) ) {
567 // Back compat for home link to match wp_page_menu()
568 $classes[] = 'current_page_item';
570 $active_parent_item_ids[] = (int) $menu_item->menu_item_parent;
571 $active_parent_object_ids[] = (int) $menu_item->post_parent;
572 $active_object = $menu_item->object;
574 // give front page item current-menu-item class when extra query arguments involved
575 } elseif ( $item_url == $front_page_url && is_front_page() ) {
576 $classes[] = 'current-menu-item';
579 if ( untrailingslashit($item_url) == home_url() )
580 $classes[] = 'menu-item-home';
583 // back-compat with wp_page_menu: add "current_page_parent" to static home page link for any non-page query
584 if ( ! empty( $home_page_id ) && 'post_type' == $menu_item->type && empty( $wp_query->is_page ) && $home_page_id == $menu_item->object_id )
585 $classes[] = 'current_page_parent';
587 $menu_items[$key]->classes = array_unique( $classes );
589 $active_ancestor_item_ids = array_filter( array_unique( $active_ancestor_item_ids ) );
590 $active_parent_item_ids = array_filter( array_unique( $active_parent_item_ids ) );
591 $active_parent_object_ids = array_filter( array_unique( $active_parent_object_ids ) );
593 // set parent's class
594 foreach ( (array) $menu_items as $key => $parent_item ) {
595 $classes = (array) $parent_item->classes;
596 $menu_items[$key]->current_item_ancestor = false;
597 $menu_items[$key]->current_item_parent = false;
600 isset( $parent_item->type ) &&
602 // ancestral post object
604 'post_type' == $parent_item->type &&
605 ! empty( $queried_object->post_type ) &&
606 is_post_type_hierarchical( $queried_object->post_type ) &&
607 in_array( $parent_item->object_id, $queried_object->ancestors ) &&
608 $parent_item->object != $queried_object->ID
613 'taxonomy' == $parent_item->type &&
614 isset( $possible_taxonomy_ancestors[ $parent_item->object ] ) &&
615 in_array( $parent_item->object_id, $possible_taxonomy_ancestors[ $parent_item->object ] ) &&
617 ! isset( $queried_object->term_id ) ||
618 $parent_item->object_id != $queried_object->term_id
623 $classes[] = empty( $queried_object->taxonomy ) ? 'current-' . $queried_object->post_type . '-ancestor' : 'current-' . $queried_object->taxonomy . '-ancestor';
626 if ( in_array( intval( $parent_item->db_id ), $active_ancestor_item_ids ) ) {
627 $classes[] = 'current-menu-ancestor';
628 $menu_items[$key]->current_item_ancestor = true;
630 if ( in_array( $parent_item->db_id, $active_parent_item_ids ) ) {
631 $classes[] = 'current-menu-parent';
632 $menu_items[$key]->current_item_parent = true;
634 if ( in_array( $parent_item->object_id, $active_parent_object_ids ) )
635 $classes[] = 'current-' . $active_object . '-parent';
637 if ( 'post_type' == $parent_item->type && 'page' == $parent_item->object ) {
638 // Back compat classes for pages to match wp_page_menu()
639 if ( in_array('current-menu-parent', $classes) )
640 $classes[] = 'current_page_parent';
641 if ( in_array('current-menu-ancestor', $classes) )
642 $classes[] = 'current_page_ancestor';
645 $menu_items[$key]->classes = array_unique( $classes );
650 * Retrieve the HTML list content for nav menu items.
652 * @uses Walker_Nav_Menu to create HTML list content.
654 * @see Walker::walk() for parameters and return description.
656 function walk_nav_menu_tree( $items, $depth, $r ) {
657 $walker = ( empty($r->walker) ) ? new Walker_Nav_Menu : $r->walker;
658 $args = array( $items, $depth, $r );
660 return call_user_func_array( array($walker, 'walk'), $args );
664 * Prevents a menu item ID from being used more than once.
669 function _nav_menu_item_id_use_once( $id, $item ) {
670 static $_used_ids = array();
671 if ( in_array( $item->ID, $_used_ids ) )
673 $_used_ids[] = $item->ID;
676 add_filter( 'nav_menu_item_id', '_nav_menu_item_id_use_once', 10, 2 );