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 var $tree_type = array( 'post_type', 'taxonomy', 'custom' );
27 * Database fields to use.
29 * @see Walker::$db_fields
31 * @todo Decouple this.
34 var $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 $args An array of arguments. @see wp_nav_menu()
47 function start_lvl( &$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 $args An array of arguments. @see wp_nav_menu()
63 function end_lvl( &$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 $id Current item ID.
81 function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
82 $indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';
86 $classes = empty( $item->classes ) ? array() : (array) $item->classes;
87 $classes[] = 'menu-item-' . $item->ID;
90 * Filter the CSS class(es) applied to a menu item's <li>.
96 * @param array $classes The CSS classes that are applied to the menu item's <li>.
97 * @param object $item The current menu item.
98 * @param array $args An array of wp_nav_menu() arguments.
100 $class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args ) );
101 $class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';
104 * Filter the ID applied to a menu item's <li>.
110 * @param string $menu_id The ID that is applied to the menu item's <li>.
111 * @param object $item The current menu item.
112 * @param array $args An array of wp_nav_menu() arguments.
114 $id = apply_filters( 'nav_menu_item_id', 'menu-item-'. $item->ID, $item, $args );
115 $id = $id ? ' id="' . esc_attr( $id ) . '"' : '';
117 $output .= $indent . '<li' . $id . $class_names .'>';
120 $atts['title'] = ! empty( $item->attr_title ) ? $item->attr_title : '';
121 $atts['target'] = ! empty( $item->target ) ? $item->target : '';
122 $atts['rel'] = ! empty( $item->xfn ) ? $item->xfn : '';
123 $atts['href'] = ! empty( $item->url ) ? $item->url : '';
126 * Filter the HTML attributes applied to a menu item's <a>.
132 * @param array $atts {
133 * The HTML attributes applied to the menu item's <a>, empty strings are ignored.
135 * @type string $title Title attribute.
136 * @type string $target Target attribute.
137 * @type string $rel The rel attribute.
138 * @type string $href The href attribute.
140 * @param object $item The current menu item.
141 * @param array $args An array of wp_nav_menu() arguments.
143 $atts = apply_filters( 'nav_menu_link_attributes', $atts, $item, $args );
146 foreach ( $atts as $attr => $value ) {
147 if ( ! empty( $value ) ) {
148 $value = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );
149 $attributes .= ' ' . $attr . '="' . $value . '"';
153 $item_output = $args->before;
154 $item_output .= '<a'. $attributes .'>';
155 /** This filter is documented in wp-includes/post-template.php */
156 $item_output .= $args->link_before . apply_filters( 'the_title', $item->title, $item->ID ) . $args->link_after;
157 $item_output .= '</a>';
158 $item_output .= $args->after;
161 * Filter a menu item's starting output.
163 * The menu item's starting output only includes $args->before, the opening <a>,
164 * the menu item's title, the closing </a>, and $args->after. Currently, there is
165 * no filter for modifying the opening and closing <li> for a menu item.
171 * @param string $item_output The menu item's starting HTML output.
172 * @param object $item Menu item data object.
173 * @param int $depth Depth of menu item. Used for padding.
174 * @param array $args An array of wp_nav_menu() arguments.
176 $output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
180 * Ends the element output, if needed.
182 * @see Walker::end_el()
186 * @param string $output Passed by reference. Used to append additional content.
187 * @param object $item Page data object. Not used.
188 * @param int $depth Depth of page. Not Used.
189 * @param array $args An array of arguments. @see wp_nav_menu()
191 function end_el( &$output, $item, $depth = 0, $args = array() ) {
192 $output .= "</li>\n";
198 * Displays a navigation menu.
202 * @param array $args {
203 * Optional. Array of nav menu arguments.
205 * @type string $menu Desired menu. Accepts (matching in order) id, slug, name. Default empty.
206 * @type string $menu_class CSS class to use for the ul element which forms the menu. Default 'menu'.
207 * @type string $menu_id The ID that is applied to the ul element which forms the menu.
208 * Default is the menu slug, incremented.
209 * @type string $container Whether to wrap the ul, and what to wrap it with. Default 'div'.
210 * @type string $container_class Class that is applied to the container. Default 'menu-{menu slug}-container'.
211 * @type string $container_id The ID that is applied to the container. Default empty.
212 * @type callback|bool $fallback_cb If the menu doesn't exists, a callback function will fire.
213 * Default is 'wp_page_menu'. Set to false for no fallback.
214 * @type string $before Text before the link text. Default empty.
215 * @type string $after Text after the link text. Default empty.
216 * @type string $link_before Text before the link. Default empty.
217 * @type string $link_after Text after the link. Default empty.
218 * @type bool $echo Whether to echo the menu or return it. Default true.
219 * @type int $depth How many levels of the hierarchy are to be included. 0 means all. Default 0.
220 * @type string $walker Allows a custom walker class to be specified. Default empty.
221 * @type string $theme_location Theme location to be used. Must be registered with register_nav_menu()
222 * in order to be selectable by the user.
223 * @type string $items_wrap How the list items should be wrapped. Default is a ul with an id and class.
224 * Uses printf() format with numbered placeholders.
226 * @return mixed Menu output if $echo is false, false if there are no items or no menu was found.
228 function wp_nav_menu( $args = array() ) {
229 static $menu_id_slugs = array();
231 $defaults = array( 'menu' => '', 'container' => 'div', 'container_class' => '', 'container_id' => '', 'menu_class' => 'menu', 'menu_id' => '',
232 'echo' => true, 'fallback_cb' => 'wp_page_menu', 'before' => '', 'after' => '', 'link_before' => '', 'link_after' => '', 'items_wrap' => '<ul id="%1$s" class="%2$s">%3$s</ul>',
233 'depth' => 0, 'walker' => '', 'theme_location' => '' );
235 $args = wp_parse_args( $args, $defaults );
237 * Filter the arguments used to display a navigation menu.
243 * @param array $args Array of wp_nav_menu() arguments.
245 $args = apply_filters( 'wp_nav_menu_args', $args );
246 $args = (object) $args;
249 * Filter whether to short-circuit the wp_nav_menu() output.
251 * Returning a non-null value to the filter will short-circuit
252 * wp_nav_menu(), echoing that value if $args->echo is true,
253 * returning that value otherwise.
259 * @param string|null $output Nav menu output to short-circuit with. Default null.
260 * @param object $args An object containing wp_nav_menu() arguments.
262 $nav_menu = apply_filters( 'pre_wp_nav_menu', null, $args );
264 if ( null !== $nav_menu ) {
273 // Get the nav menu based on the requested menu
274 $menu = wp_get_nav_menu_object( $args->menu );
276 // Get the nav menu based on the theme_location
277 if ( ! $menu && $args->theme_location && ( $locations = get_nav_menu_locations() ) && isset( $locations[ $args->theme_location ] ) )
278 $menu = wp_get_nav_menu_object( $locations[ $args->theme_location ] );
280 // get the first menu that has items if we still can't find a menu
281 if ( ! $menu && !$args->theme_location ) {
282 $menus = wp_get_nav_menus();
283 foreach ( $menus as $menu_maybe ) {
284 if ( $menu_items = wp_get_nav_menu_items( $menu_maybe->term_id, array( 'update_post_term_cache' => false ) ) ) {
291 // If the menu exists, get its items.
292 if ( $menu && ! is_wp_error($menu) && !isset($menu_items) )
293 $menu_items = wp_get_nav_menu_items( $menu->term_id, array( 'update_post_term_cache' => false ) );
296 * If no menu was found:
297 * - Fall back (if one was specified), or bail.
299 * If no menu items were found:
300 * - Fall back, but only if no theme location was specified.
303 if ( ( !$menu || is_wp_error($menu) || ( isset($menu_items) && empty($menu_items) && !$args->theme_location ) )
304 && $args->fallback_cb && is_callable( $args->fallback_cb ) )
305 return call_user_func( $args->fallback_cb, (array) $args );
307 if ( ! $menu || is_wp_error( $menu ) )
310 $nav_menu = $items = '';
312 $show_container = false;
313 if ( $args->container ) {
315 * Filter the list of HTML tags that are valid for use as menu containers.
319 * @param array $tags The acceptable HTML tags for use as menu containers.
320 * Default is array containing 'div' and 'nav'.
322 $allowed_tags = apply_filters( 'wp_nav_menu_container_allowedtags', array( 'div', 'nav' ) );
323 if ( in_array( $args->container, $allowed_tags ) ) {
324 $show_container = true;
325 $class = $args->container_class ? ' class="' . esc_attr( $args->container_class ) . '"' : ' class="menu-'. $menu->slug .'-container"';
326 $id = $args->container_id ? ' id="' . esc_attr( $args->container_id ) . '"' : '';
327 $nav_menu .= '<'. $args->container . $id . $class . '>';
331 // Set up the $menu_item variables
332 _wp_menu_item_classes_by_context( $menu_items );
334 $sorted_menu_items = $menu_items_with_children = array();
335 foreach ( (array) $menu_items as $menu_item ) {
336 $sorted_menu_items[ $menu_item->menu_order ] = $menu_item;
337 if ( $menu_item->menu_item_parent )
338 $menu_items_with_children[ $menu_item->menu_item_parent ] = true;
341 // Add the menu-item-has-children class where applicable
342 if ( $menu_items_with_children ) {
343 foreach ( $sorted_menu_items as &$menu_item ) {
344 if ( isset( $menu_items_with_children[ $menu_item->ID ] ) )
345 $menu_item->classes[] = 'menu-item-has-children';
349 unset( $menu_items, $menu_item );
352 * Filter the sorted list of menu item objects before generating the menu's HTML.
356 * @param array $sorted_menu_items The menu items, sorted by each menu item's menu order.
358 $sorted_menu_items = apply_filters( 'wp_nav_menu_objects', $sorted_menu_items, $args );
360 $items .= walk_nav_menu_tree( $sorted_menu_items, $args->depth, $args );
361 unset($sorted_menu_items);
364 if ( ! empty( $args->menu_id ) ) {
365 $wrap_id = $args->menu_id;
367 $wrap_id = 'menu-' . $menu->slug;
368 while ( in_array( $wrap_id, $menu_id_slugs ) ) {
369 if ( preg_match( '#-(\d+)$#', $wrap_id, $matches ) )
370 $wrap_id = preg_replace('#-(\d+)$#', '-' . ++$matches[1], $wrap_id );
372 $wrap_id = $wrap_id . '-1';
375 $menu_id_slugs[] = $wrap_id;
377 $wrap_class = $args->menu_class ? $args->menu_class : '';
380 * Filter the HTML list content for navigation menus.
386 * @param string $items The HTML list content for the menu items.
387 * @param array $args Array of wp_nav_menu() arguments.
389 $items = apply_filters( 'wp_nav_menu_items', $items, $args );
391 * Filter the HTML list content for a specific navigation menu.
397 * @param string $items The HTML list content for the menu items.
398 * @param array $args Array of wp_nav_menu() arguments.
400 $items = apply_filters( "wp_nav_menu_{$menu->slug}_items", $items, $args );
402 // Don't print any markup if there are no items at this point.
403 if ( empty( $items ) )
406 $nav_menu .= sprintf( $args->items_wrap, esc_attr( $wrap_id ), esc_attr( $wrap_class ), $items );
409 if ( $show_container )
410 $nav_menu .= '</' . $args->container . '>';
413 * Filter the HTML content for navigation menus.
419 * @param string $nav_menu The HTML content for the navigation menu.
420 * @param array $args Array of wp_nav_menu() arguments.
422 $nav_menu = apply_filters( 'wp_nav_menu', $nav_menu, $args );
431 * Add the class property classes for the current context, if applicable.
436 * @param array $menu_items The current menu item objects to which to add the class property information.
438 function _wp_menu_item_classes_by_context( &$menu_items ) {
439 global $wp_query, $wp_rewrite;
441 $queried_object = $wp_query->get_queried_object();
442 $queried_object_id = (int) $wp_query->queried_object_id;
445 $active_ancestor_item_ids = array();
446 $active_parent_item_ids = array();
447 $active_parent_object_ids = array();
448 $possible_taxonomy_ancestors = array();
449 $possible_object_parents = array();
450 $home_page_id = (int) get_option( 'page_for_posts' );
452 if ( $wp_query->is_singular && ! empty( $queried_object->post_type ) && ! is_post_type_hierarchical( $queried_object->post_type ) ) {
453 foreach ( (array) get_object_taxonomies( $queried_object->post_type ) as $taxonomy ) {
454 if ( is_taxonomy_hierarchical( $taxonomy ) ) {
455 $term_hierarchy = _get_term_hierarchy( $taxonomy );
456 $terms = wp_get_object_terms( $queried_object_id, $taxonomy, array( 'fields' => 'ids' ) );
457 if ( is_array( $terms ) ) {
458 $possible_object_parents = array_merge( $possible_object_parents, $terms );
459 $term_to_ancestor = array();
460 foreach ( (array) $term_hierarchy as $anc => $descs ) {
461 foreach ( (array) $descs as $desc )
462 $term_to_ancestor[ $desc ] = $anc;
465 foreach ( $terms as $desc ) {
467 $possible_taxonomy_ancestors[ $taxonomy ][] = $desc;
468 if ( isset( $term_to_ancestor[ $desc ] ) ) {
469 $_desc = $term_to_ancestor[ $desc ];
470 unset( $term_to_ancestor[ $desc ] );
475 } while ( ! empty( $desc ) );
480 } elseif ( ! empty( $queried_object->taxonomy ) && is_taxonomy_hierarchical( $queried_object->taxonomy ) ) {
481 $term_hierarchy = _get_term_hierarchy( $queried_object->taxonomy );
482 $term_to_ancestor = array();
483 foreach ( (array) $term_hierarchy as $anc => $descs ) {
484 foreach ( (array) $descs as $desc )
485 $term_to_ancestor[ $desc ] = $anc;
487 $desc = $queried_object->term_id;
489 $possible_taxonomy_ancestors[ $queried_object->taxonomy ][] = $desc;
490 if ( isset( $term_to_ancestor[ $desc ] ) ) {
491 $_desc = $term_to_ancestor[ $desc ];
492 unset( $term_to_ancestor[ $desc ] );
497 } while ( ! empty( $desc ) );
500 $possible_object_parents = array_filter( $possible_object_parents );
502 $front_page_url = home_url();
504 foreach ( (array) $menu_items as $key => $menu_item ) {
506 $menu_items[$key]->current = false;
508 $classes = (array) $menu_item->classes;
509 $classes[] = 'menu-item';
510 $classes[] = 'menu-item-type-' . $menu_item->type;
511 $classes[] = 'menu-item-object-' . $menu_item->object;
513 // if the menu item corresponds to a taxonomy term for the currently-queried non-hierarchical post object
514 if ( $wp_query->is_singular && 'taxonomy' == $menu_item->type && in_array( $menu_item->object_id, $possible_object_parents ) ) {
515 $active_parent_object_ids[] = (int) $menu_item->object_id;
516 $active_parent_item_ids[] = (int) $menu_item->db_id;
517 $active_object = $queried_object->post_type;
519 // if the menu item corresponds to the currently-queried post or taxonomy object
521 $menu_item->object_id == $queried_object_id &&
523 ( ! empty( $home_page_id ) && 'post_type' == $menu_item->type && $wp_query->is_home && $home_page_id == $menu_item->object_id ) ||
524 ( 'post_type' == $menu_item->type && $wp_query->is_singular ) ||
525 ( 'taxonomy' == $menu_item->type && ( $wp_query->is_category || $wp_query->is_tag || $wp_query->is_tax ) && $queried_object->taxonomy == $menu_item->object )
528 $classes[] = 'current-menu-item';
529 $menu_items[$key]->current = true;
530 $_anc_id = (int) $menu_item->db_id;
533 ( $_anc_id = get_post_meta( $_anc_id, '_menu_item_menu_item_parent', true ) ) &&
534 ! in_array( $_anc_id, $active_ancestor_item_ids )
536 $active_ancestor_item_ids[] = $_anc_id;
539 if ( 'post_type' == $menu_item->type && 'page' == $menu_item->object ) {
540 // Back compat classes for pages to match wp_page_menu()
541 $classes[] = 'page_item';
542 $classes[] = 'page-item-' . $menu_item->object_id;
543 $classes[] = 'current_page_item';
545 $active_parent_item_ids[] = (int) $menu_item->menu_item_parent;
546 $active_parent_object_ids[] = (int) $menu_item->post_parent;
547 $active_object = $menu_item->object;
549 // if the menu item corresponds to the currently-requested URL
550 } elseif ( 'custom' == $menu_item->object ) {
551 $_root_relative_current = untrailingslashit( $_SERVER['REQUEST_URI'] );
552 $current_url = set_url_scheme( 'http://' . $_SERVER['HTTP_HOST'] . $_root_relative_current );
553 $raw_item_url = strpos( $menu_item->url, '#' ) ? substr( $menu_item->url, 0, strpos( $menu_item->url, '#' ) ) : $menu_item->url;
554 $item_url = untrailingslashit( $raw_item_url );
555 $_indexless_current = untrailingslashit( preg_replace( '/' . preg_quote( $wp_rewrite->index, '/' ) . '$/', '', $current_url ) );
557 if ( $raw_item_url && in_array( $item_url, array( $current_url, $_indexless_current, $_root_relative_current ) ) ) {
558 $classes[] = 'current-menu-item';
559 $menu_items[$key]->current = true;
560 $_anc_id = (int) $menu_item->db_id;
563 ( $_anc_id = get_post_meta( $_anc_id, '_menu_item_menu_item_parent', true ) ) &&
564 ! in_array( $_anc_id, $active_ancestor_item_ids )
566 $active_ancestor_item_ids[] = $_anc_id;
569 if ( in_array( home_url(), array( untrailingslashit( $current_url ), untrailingslashit( $_indexless_current ) ) ) ) {
570 // Back compat for home link to match wp_page_menu()
571 $classes[] = 'current_page_item';
573 $active_parent_item_ids[] = (int) $menu_item->menu_item_parent;
574 $active_parent_object_ids[] = (int) $menu_item->post_parent;
575 $active_object = $menu_item->object;
577 // give front page item current-menu-item class when extra query arguments involved
578 } elseif ( $item_url == $front_page_url && is_front_page() ) {
579 $classes[] = 'current-menu-item';
582 if ( untrailingslashit($item_url) == home_url() )
583 $classes[] = 'menu-item-home';
586 // back-compat with wp_page_menu: add "current_page_parent" to static home page link for any non-page query
587 if ( ! empty( $home_page_id ) && 'post_type' == $menu_item->type && empty( $wp_query->is_page ) && $home_page_id == $menu_item->object_id )
588 $classes[] = 'current_page_parent';
590 $menu_items[$key]->classes = array_unique( $classes );
592 $active_ancestor_item_ids = array_filter( array_unique( $active_ancestor_item_ids ) );
593 $active_parent_item_ids = array_filter( array_unique( $active_parent_item_ids ) );
594 $active_parent_object_ids = array_filter( array_unique( $active_parent_object_ids ) );
596 // set parent's class
597 foreach ( (array) $menu_items as $key => $parent_item ) {
598 $classes = (array) $parent_item->classes;
599 $menu_items[$key]->current_item_ancestor = false;
600 $menu_items[$key]->current_item_parent = false;
603 isset( $parent_item->type ) &&
605 // ancestral post object
607 'post_type' == $parent_item->type &&
608 ! empty( $queried_object->post_type ) &&
609 is_post_type_hierarchical( $queried_object->post_type ) &&
610 in_array( $parent_item->object_id, $queried_object->ancestors ) &&
611 $parent_item->object != $queried_object->ID
616 'taxonomy' == $parent_item->type &&
617 isset( $possible_taxonomy_ancestors[ $parent_item->object ] ) &&
618 in_array( $parent_item->object_id, $possible_taxonomy_ancestors[ $parent_item->object ] ) &&
620 ! isset( $queried_object->term_id ) ||
621 $parent_item->object_id != $queried_object->term_id
626 $classes[] = empty( $queried_object->taxonomy ) ? 'current-' . $queried_object->post_type . '-ancestor' : 'current-' . $queried_object->taxonomy . '-ancestor';
629 if ( in_array( intval( $parent_item->db_id ), $active_ancestor_item_ids ) ) {
630 $classes[] = 'current-menu-ancestor';
631 $menu_items[$key]->current_item_ancestor = true;
633 if ( in_array( $parent_item->db_id, $active_parent_item_ids ) ) {
634 $classes[] = 'current-menu-parent';
635 $menu_items[$key]->current_item_parent = true;
637 if ( in_array( $parent_item->object_id, $active_parent_object_ids ) )
638 $classes[] = 'current-' . $active_object . '-parent';
640 if ( 'post_type' == $parent_item->type && 'page' == $parent_item->object ) {
641 // Back compat classes for pages to match wp_page_menu()
642 if ( in_array('current-menu-parent', $classes) )
643 $classes[] = 'current_page_parent';
644 if ( in_array('current-menu-ancestor', $classes) )
645 $classes[] = 'current_page_ancestor';
648 $menu_items[$key]->classes = array_unique( $classes );
653 * Retrieve the HTML list content for nav menu items.
655 * @uses Walker_Nav_Menu to create HTML list content.
657 * @see Walker::walk() for parameters and return description.
659 function walk_nav_menu_tree( $items, $depth, $r ) {
660 $walker = ( empty($r->walker) ) ? new Walker_Nav_Menu : $r->walker;
661 $args = array( $items, $depth, $r );
663 return call_user_func_array( array($walker, 'walk'), $args );
667 * Prevents a menu item ID from being used more than once.
672 function _nav_menu_item_id_use_once( $id, $item ) {
673 static $_used_ids = array();
674 if ( in_array( $item->ID, $_used_ids ) )
676 $_used_ids[] = $item->ID;
679 add_filter( 'nav_menu_item_id', '_nav_menu_item_id_use_once', 10, 2 );