nav-menu-template.php (23296B)
1 <?php 2 /** 3 * Nav Menu API: Template functions 4 * 5 * @package WordPress 6 * @subpackage Nav_Menus 7 * @since 3.0.0 8 */ 9 10 /** Walker_Nav_Menu class */ 11 require_once ABSPATH . WPINC . '/class-walker-nav-menu.php'; 12 13 /** 14 * Displays a navigation menu. 15 * 16 * @since 3.0.0 17 * @since 4.7.0 Added the `item_spacing` argument. 18 * @since 5.5.0 Added the `container_aria_label` argument. 19 * 20 * @param array $args { 21 * Optional. Array of nav menu arguments. 22 * 23 * @type int|string|WP_Term $menu Desired menu. Accepts a menu ID, slug, name, or object. 24 * Default empty. 25 * @type string $menu_class CSS class to use for the ul element which forms the menu. 26 * Default 'menu'. 27 * @type string $menu_id The ID that is applied to the ul element which forms the menu. 28 * Default is the menu slug, incremented. 29 * @type string $container Whether to wrap the ul, and what to wrap it with. 30 * Default 'div'. 31 * @type string $container_class Class that is applied to the container. 32 * Default 'menu-{menu slug}-container'. 33 * @type string $container_id The ID that is applied to the container. Default empty. 34 * @type string $container_aria_label The aria-label attribute that is applied to the container 35 * when it's a nav element. Default empty. 36 * @type callable|false $fallback_cb If the menu doesn't exist, a callback function will fire. 37 * Default is 'wp_page_menu'. Set to false for no fallback. 38 * @type string $before Text before the link markup. Default empty. 39 * @type string $after Text after the link markup. Default empty. 40 * @type string $link_before Text before the link text. Default empty. 41 * @type string $link_after Text after the link text. Default empty. 42 * @type bool $echo Whether to echo the menu or return it. Default true. 43 * @type int $depth How many levels of the hierarchy are to be included. 44 * 0 means all. Default 0. 45 * Default 0. 46 * @type object $walker Instance of a custom walker class. Default empty. 47 * @type string $theme_location Theme location to be used. Must be registered with 48 * register_nav_menu() in order to be selectable by the user. 49 * @type string $items_wrap How the list items should be wrapped. Uses printf() format with 50 * numbered placeholders. Default is a ul with an id and class. 51 * @type string $item_spacing Whether to preserve whitespace within the menu's HTML. 52 * Accepts 'preserve' or 'discard'. Default 'preserve'. 53 * } 54 * @return void|string|false Void if 'echo' argument is true, menu output if 'echo' is false. 55 * False if there are no items or no menu was found. 56 */ 57 function wp_nav_menu( $args = array() ) { 58 static $menu_id_slugs = array(); 59 60 $defaults = array( 61 'menu' => '', 62 'container' => 'div', 63 'container_class' => '', 64 'container_id' => '', 65 'container_aria_label' => '', 66 'menu_class' => 'menu', 67 'menu_id' => '', 68 'echo' => true, 69 'fallback_cb' => 'wp_page_menu', 70 'before' => '', 71 'after' => '', 72 'link_before' => '', 73 'link_after' => '', 74 'items_wrap' => '<ul id="%1$s" class="%2$s">%3$s</ul>', 75 'item_spacing' => 'preserve', 76 'depth' => 0, 77 'walker' => '', 78 'theme_location' => '', 79 ); 80 81 $args = wp_parse_args( $args, $defaults ); 82 83 if ( ! in_array( $args['item_spacing'], array( 'preserve', 'discard' ), true ) ) { 84 // Invalid value, fall back to default. 85 $args['item_spacing'] = $defaults['item_spacing']; 86 } 87 88 /** 89 * Filters the arguments used to display a navigation menu. 90 * 91 * @since 3.0.0 92 * 93 * @see wp_nav_menu() 94 * 95 * @param array $args Array of wp_nav_menu() arguments. 96 */ 97 $args = apply_filters( 'wp_nav_menu_args', $args ); 98 $args = (object) $args; 99 100 /** 101 * Filters whether to short-circuit the wp_nav_menu() output. 102 * 103 * Returning a non-null value from the filter will short-circuit wp_nav_menu(), 104 * echoing that value if $args->echo is true, returning that value otherwise. 105 * 106 * @since 3.9.0 107 * 108 * @see wp_nav_menu() 109 * 110 * @param string|null $output Nav menu output to short-circuit with. Default null. 111 * @param stdClass $args An object containing wp_nav_menu() arguments. 112 */ 113 $nav_menu = apply_filters( 'pre_wp_nav_menu', null, $args ); 114 115 if ( null !== $nav_menu ) { 116 if ( $args->echo ) { 117 echo $nav_menu; 118 return; 119 } 120 121 return $nav_menu; 122 } 123 124 // Get the nav menu based on the requested menu. 125 $menu = wp_get_nav_menu_object( $args->menu ); 126 127 // Get the nav menu based on the theme_location. 128 $locations = get_nav_menu_locations(); 129 if ( ! $menu && $args->theme_location && $locations && isset( $locations[ $args->theme_location ] ) ) { 130 $menu = wp_get_nav_menu_object( $locations[ $args->theme_location ] ); 131 } 132 133 // Get the first menu that has items if we still can't find a menu. 134 if ( ! $menu && ! $args->theme_location ) { 135 $menus = wp_get_nav_menus(); 136 foreach ( $menus as $menu_maybe ) { 137 $menu_items = wp_get_nav_menu_items( $menu_maybe->term_id, array( 'update_post_term_cache' => false ) ); 138 if ( $menu_items ) { 139 $menu = $menu_maybe; 140 break; 141 } 142 } 143 } 144 145 if ( empty( $args->menu ) ) { 146 $args->menu = $menu; 147 } 148 149 // If the menu exists, get its items. 150 if ( $menu && ! is_wp_error( $menu ) && ! isset( $menu_items ) ) { 151 $menu_items = wp_get_nav_menu_items( $menu->term_id, array( 'update_post_term_cache' => false ) ); 152 } 153 154 /* 155 * If no menu was found: 156 * - Fall back (if one was specified), or bail. 157 * 158 * If no menu items were found: 159 * - Fall back, but only if no theme location was specified. 160 * - Otherwise, bail. 161 */ 162 if ( ( ! $menu || is_wp_error( $menu ) || ( isset( $menu_items ) && empty( $menu_items ) && ! $args->theme_location ) ) 163 && isset( $args->fallback_cb ) && $args->fallback_cb && is_callable( $args->fallback_cb ) ) { 164 return call_user_func( $args->fallback_cb, (array) $args ); 165 } 166 167 if ( ! $menu || is_wp_error( $menu ) ) { 168 return false; 169 } 170 171 $nav_menu = ''; 172 $items = ''; 173 174 $show_container = false; 175 if ( $args->container ) { 176 /** 177 * Filters the list of HTML tags that are valid for use as menu containers. 178 * 179 * @since 3.0.0 180 * 181 * @param string[] $tags The acceptable HTML tags for use as menu containers. 182 * Default is array containing 'div' and 'nav'. 183 */ 184 $allowed_tags = apply_filters( 'wp_nav_menu_container_allowedtags', array( 'div', 'nav' ) ); 185 186 if ( is_string( $args->container ) && in_array( $args->container, $allowed_tags, true ) ) { 187 $show_container = true; 188 $class = $args->container_class ? ' class="' . esc_attr( $args->container_class ) . '"' : ' class="menu-' . $menu->slug . '-container"'; 189 $id = $args->container_id ? ' id="' . esc_attr( $args->container_id ) . '"' : ''; 190 $aria_label = ( 'nav' === $args->container && $args->container_aria_label ) ? ' aria-label="' . esc_attr( $args->container_aria_label ) . '"' : ''; 191 $nav_menu .= '<' . $args->container . $id . $class . $aria_label . '>'; 192 } 193 } 194 195 // Set up the $menu_item variables. 196 _wp_menu_item_classes_by_context( $menu_items ); 197 198 $sorted_menu_items = array(); 199 $menu_items_with_children = array(); 200 foreach ( (array) $menu_items as $menu_item ) { 201 $sorted_menu_items[ $menu_item->menu_order ] = $menu_item; 202 if ( $menu_item->menu_item_parent ) { 203 $menu_items_with_children[ $menu_item->menu_item_parent ] = true; 204 } 205 } 206 207 // Add the menu-item-has-children class where applicable. 208 if ( $menu_items_with_children ) { 209 foreach ( $sorted_menu_items as &$menu_item ) { 210 if ( isset( $menu_items_with_children[ $menu_item->ID ] ) ) { 211 $menu_item->classes[] = 'menu-item-has-children'; 212 } 213 } 214 } 215 216 unset( $menu_items, $menu_item ); 217 218 /** 219 * Filters the sorted list of menu item objects before generating the menu's HTML. 220 * 221 * @since 3.1.0 222 * 223 * @param array $sorted_menu_items The menu items, sorted by each menu item's menu order. 224 * @param stdClass $args An object containing wp_nav_menu() arguments. 225 */ 226 $sorted_menu_items = apply_filters( 'wp_nav_menu_objects', $sorted_menu_items, $args ); 227 228 $items .= walk_nav_menu_tree( $sorted_menu_items, $args->depth, $args ); 229 unset( $sorted_menu_items ); 230 231 // Attributes. 232 if ( ! empty( $args->menu_id ) ) { 233 $wrap_id = $args->menu_id; 234 } else { 235 $wrap_id = 'menu-' . $menu->slug; 236 237 while ( in_array( $wrap_id, $menu_id_slugs, true ) ) { 238 if ( preg_match( '#-(\d+)$#', $wrap_id, $matches ) ) { 239 $wrap_id = preg_replace( '#-(\d+)$#', '-' . ++$matches[1], $wrap_id ); 240 } else { 241 $wrap_id = $wrap_id . '-1'; 242 } 243 } 244 } 245 $menu_id_slugs[] = $wrap_id; 246 247 $wrap_class = $args->menu_class ? $args->menu_class : ''; 248 249 /** 250 * Filters the HTML list content for navigation menus. 251 * 252 * @since 3.0.0 253 * 254 * @see wp_nav_menu() 255 * 256 * @param string $items The HTML list content for the menu items. 257 * @param stdClass $args An object containing wp_nav_menu() arguments. 258 */ 259 $items = apply_filters( 'wp_nav_menu_items', $items, $args ); 260 /** 261 * Filters the HTML list content for a specific navigation menu. 262 * 263 * @since 3.0.0 264 * 265 * @see wp_nav_menu() 266 * 267 * @param string $items The HTML list content for the menu items. 268 * @param stdClass $args An object containing wp_nav_menu() arguments. 269 */ 270 $items = apply_filters( "wp_nav_menu_{$menu->slug}_items", $items, $args ); 271 272 // Don't print any markup if there are no items at this point. 273 if ( empty( $items ) ) { 274 return false; 275 } 276 277 $nav_menu .= sprintf( $args->items_wrap, esc_attr( $wrap_id ), esc_attr( $wrap_class ), $items ); 278 unset( $items ); 279 280 if ( $show_container ) { 281 $nav_menu .= '</' . $args->container . '>'; 282 } 283 284 /** 285 * Filters the HTML content for navigation menus. 286 * 287 * @since 3.0.0 288 * 289 * @see wp_nav_menu() 290 * 291 * @param string $nav_menu The HTML content for the navigation menu. 292 * @param stdClass $args An object containing wp_nav_menu() arguments. 293 */ 294 $nav_menu = apply_filters( 'wp_nav_menu', $nav_menu, $args ); 295 296 if ( $args->echo ) { 297 echo $nav_menu; 298 } else { 299 return $nav_menu; 300 } 301 } 302 303 /** 304 * Adds the class property classes for the current context, if applicable. 305 * 306 * @access private 307 * @since 3.0.0 308 * 309 * @global WP_Query $wp_query WordPress Query object. 310 * @global WP_Rewrite $wp_rewrite WordPress rewrite component. 311 * 312 * @param array $menu_items The current menu item objects to which to add the class property information. 313 */ 314 function _wp_menu_item_classes_by_context( &$menu_items ) { 315 global $wp_query, $wp_rewrite; 316 317 $queried_object = $wp_query->get_queried_object(); 318 $queried_object_id = (int) $wp_query->queried_object_id; 319 320 $active_object = ''; 321 $active_ancestor_item_ids = array(); 322 $active_parent_item_ids = array(); 323 $active_parent_object_ids = array(); 324 $possible_taxonomy_ancestors = array(); 325 $possible_object_parents = array(); 326 $home_page_id = (int) get_option( 'page_for_posts' ); 327 328 if ( $wp_query->is_singular && ! empty( $queried_object->post_type ) && ! is_post_type_hierarchical( $queried_object->post_type ) ) { 329 foreach ( (array) get_object_taxonomies( $queried_object->post_type ) as $taxonomy ) { 330 if ( is_taxonomy_hierarchical( $taxonomy ) ) { 331 $term_hierarchy = _get_term_hierarchy( $taxonomy ); 332 $terms = wp_get_object_terms( $queried_object_id, $taxonomy, array( 'fields' => 'ids' ) ); 333 if ( is_array( $terms ) ) { 334 $possible_object_parents = array_merge( $possible_object_parents, $terms ); 335 $term_to_ancestor = array(); 336 foreach ( (array) $term_hierarchy as $anc => $descs ) { 337 foreach ( (array) $descs as $desc ) { 338 $term_to_ancestor[ $desc ] = $anc; 339 } 340 } 341 342 foreach ( $terms as $desc ) { 343 do { 344 $possible_taxonomy_ancestors[ $taxonomy ][] = $desc; 345 if ( isset( $term_to_ancestor[ $desc ] ) ) { 346 $_desc = $term_to_ancestor[ $desc ]; 347 unset( $term_to_ancestor[ $desc ] ); 348 $desc = $_desc; 349 } else { 350 $desc = 0; 351 } 352 } while ( ! empty( $desc ) ); 353 } 354 } 355 } 356 } 357 } elseif ( ! empty( $queried_object->taxonomy ) && is_taxonomy_hierarchical( $queried_object->taxonomy ) ) { 358 $term_hierarchy = _get_term_hierarchy( $queried_object->taxonomy ); 359 $term_to_ancestor = array(); 360 foreach ( (array) $term_hierarchy as $anc => $descs ) { 361 foreach ( (array) $descs as $desc ) { 362 $term_to_ancestor[ $desc ] = $anc; 363 } 364 } 365 $desc = $queried_object->term_id; 366 do { 367 $possible_taxonomy_ancestors[ $queried_object->taxonomy ][] = $desc; 368 if ( isset( $term_to_ancestor[ $desc ] ) ) { 369 $_desc = $term_to_ancestor[ $desc ]; 370 unset( $term_to_ancestor[ $desc ] ); 371 $desc = $_desc; 372 } else { 373 $desc = 0; 374 } 375 } while ( ! empty( $desc ) ); 376 } 377 378 $possible_object_parents = array_filter( $possible_object_parents ); 379 380 $front_page_url = home_url(); 381 $front_page_id = (int) get_option( 'page_on_front' ); 382 $privacy_policy_page_id = (int) get_option( 'wp_page_for_privacy_policy' ); 383 384 foreach ( (array) $menu_items as $key => $menu_item ) { 385 386 $menu_items[ $key ]->current = false; 387 388 $classes = (array) $menu_item->classes; 389 $classes[] = 'menu-item'; 390 $classes[] = 'menu-item-type-' . $menu_item->type; 391 $classes[] = 'menu-item-object-' . $menu_item->object; 392 393 // This menu item is set as the 'Front Page'. 394 if ( 'post_type' === $menu_item->type && $front_page_id === (int) $menu_item->object_id ) { 395 $classes[] = 'menu-item-home'; 396 } 397 398 // This menu item is set as the 'Privacy Policy Page'. 399 if ( 'post_type' === $menu_item->type && $privacy_policy_page_id === (int) $menu_item->object_id ) { 400 $classes[] = 'menu-item-privacy-policy'; 401 } 402 403 // If the menu item corresponds to a taxonomy term for the currently queried non-hierarchical post object. 404 if ( $wp_query->is_singular && 'taxonomy' === $menu_item->type 405 && in_array( (int) $menu_item->object_id, $possible_object_parents, true ) 406 ) { 407 $active_parent_object_ids[] = (int) $menu_item->object_id; 408 $active_parent_item_ids[] = (int) $menu_item->db_id; 409 $active_object = $queried_object->post_type; 410 411 // If the menu item corresponds to the currently queried post or taxonomy object. 412 } elseif ( 413 $menu_item->object_id == $queried_object_id 414 && ( 415 ( ! empty( $home_page_id ) && 'post_type' === $menu_item->type 416 && $wp_query->is_home && $home_page_id == $menu_item->object_id ) 417 || ( 'post_type' === $menu_item->type && $wp_query->is_singular ) 418 || ( 'taxonomy' === $menu_item->type 419 && ( $wp_query->is_category || $wp_query->is_tag || $wp_query->is_tax ) 420 && $queried_object->taxonomy == $menu_item->object ) 421 ) 422 ) { 423 $classes[] = 'current-menu-item'; 424 $menu_items[ $key ]->current = true; 425 $_anc_id = (int) $menu_item->db_id; 426 427 while ( 428 ( $_anc_id = (int) get_post_meta( $_anc_id, '_menu_item_menu_item_parent', true ) ) 429 && ! in_array( $_anc_id, $active_ancestor_item_ids, true ) 430 ) { 431 $active_ancestor_item_ids[] = $_anc_id; 432 } 433 434 if ( 'post_type' === $menu_item->type && 'page' === $menu_item->object ) { 435 // Back compat classes for pages to match wp_page_menu(). 436 $classes[] = 'page_item'; 437 $classes[] = 'page-item-' . $menu_item->object_id; 438 $classes[] = 'current_page_item'; 439 } 440 441 $active_parent_item_ids[] = (int) $menu_item->menu_item_parent; 442 $active_parent_object_ids[] = (int) $menu_item->post_parent; 443 $active_object = $menu_item->object; 444 445 // If the menu item corresponds to the currently queried post type archive. 446 } elseif ( 447 'post_type_archive' === $menu_item->type 448 && is_post_type_archive( array( $menu_item->object ) ) 449 ) { 450 $classes[] = 'current-menu-item'; 451 $menu_items[ $key ]->current = true; 452 $_anc_id = (int) $menu_item->db_id; 453 454 while ( 455 ( $_anc_id = (int) get_post_meta( $_anc_id, '_menu_item_menu_item_parent', true ) ) 456 && ! in_array( $_anc_id, $active_ancestor_item_ids, true ) 457 ) { 458 $active_ancestor_item_ids[] = $_anc_id; 459 } 460 461 $active_parent_item_ids[] = (int) $menu_item->menu_item_parent; 462 463 // If the menu item corresponds to the currently requested URL. 464 } elseif ( 'custom' === $menu_item->object && isset( $_SERVER['HTTP_HOST'] ) ) { 465 $_root_relative_current = untrailingslashit( $_SERVER['REQUEST_URI'] ); 466 467 // If it's the customize page then it will strip the query var off the URL before entering the comparison block. 468 if ( is_customize_preview() ) { 469 $_root_relative_current = strtok( untrailingslashit( $_SERVER['REQUEST_URI'] ), '?' ); 470 } 471 472 $current_url = set_url_scheme( 'http://' . $_SERVER['HTTP_HOST'] . $_root_relative_current ); 473 $raw_item_url = strpos( $menu_item->url, '#' ) ? substr( $menu_item->url, 0, strpos( $menu_item->url, '#' ) ) : $menu_item->url; 474 $item_url = set_url_scheme( untrailingslashit( $raw_item_url ) ); 475 $_indexless_current = untrailingslashit( preg_replace( '/' . preg_quote( $wp_rewrite->index, '/' ) . '$/', '', $current_url ) ); 476 477 $matches = array( 478 $current_url, 479 urldecode( $current_url ), 480 $_indexless_current, 481 urldecode( $_indexless_current ), 482 $_root_relative_current, 483 urldecode( $_root_relative_current ), 484 ); 485 486 if ( $raw_item_url && in_array( $item_url, $matches, true ) ) { 487 $classes[] = 'current-menu-item'; 488 $menu_items[ $key ]->current = true; 489 $_anc_id = (int) $menu_item->db_id; 490 491 while ( 492 ( $_anc_id = (int) get_post_meta( $_anc_id, '_menu_item_menu_item_parent', true ) ) 493 && ! in_array( $_anc_id, $active_ancestor_item_ids, true ) 494 ) { 495 $active_ancestor_item_ids[] = $_anc_id; 496 } 497 498 if ( in_array( home_url(), array( untrailingslashit( $current_url ), untrailingslashit( $_indexless_current ) ), true ) ) { 499 // Back compat for home link to match wp_page_menu(). 500 $classes[] = 'current_page_item'; 501 } 502 $active_parent_item_ids[] = (int) $menu_item->menu_item_parent; 503 $active_parent_object_ids[] = (int) $menu_item->post_parent; 504 $active_object = $menu_item->object; 505 506 // Give front page item the 'current-menu-item' class when extra query arguments are involved. 507 } elseif ( $item_url == $front_page_url && is_front_page() ) { 508 $classes[] = 'current-menu-item'; 509 } 510 511 if ( untrailingslashit( $item_url ) == home_url() ) { 512 $classes[] = 'menu-item-home'; 513 } 514 } 515 516 // Back-compat with wp_page_menu(): add "current_page_parent" to static home page link for any non-page query. 517 if ( ! empty( $home_page_id ) && 'post_type' === $menu_item->type 518 && empty( $wp_query->is_page ) && $home_page_id == $menu_item->object_id 519 ) { 520 $classes[] = 'current_page_parent'; 521 } 522 523 $menu_items[ $key ]->classes = array_unique( $classes ); 524 } 525 $active_ancestor_item_ids = array_filter( array_unique( $active_ancestor_item_ids ) ); 526 $active_parent_item_ids = array_filter( array_unique( $active_parent_item_ids ) ); 527 $active_parent_object_ids = array_filter( array_unique( $active_parent_object_ids ) ); 528 529 // Set parent's class. 530 foreach ( (array) $menu_items as $key => $parent_item ) { 531 $classes = (array) $parent_item->classes; 532 $menu_items[ $key ]->current_item_ancestor = false; 533 $menu_items[ $key ]->current_item_parent = false; 534 535 if ( 536 isset( $parent_item->type ) 537 && ( 538 // Ancestral post object. 539 ( 540 'post_type' === $parent_item->type 541 && ! empty( $queried_object->post_type ) 542 && is_post_type_hierarchical( $queried_object->post_type ) 543 && in_array( (int) $parent_item->object_id, $queried_object->ancestors, true ) 544 && $parent_item->object != $queried_object->ID 545 ) || 546 547 // Ancestral term. 548 ( 549 'taxonomy' === $parent_item->type 550 && isset( $possible_taxonomy_ancestors[ $parent_item->object ] ) 551 && in_array( (int) $parent_item->object_id, $possible_taxonomy_ancestors[ $parent_item->object ], true ) 552 && ( 553 ! isset( $queried_object->term_id ) || 554 $parent_item->object_id != $queried_object->term_id 555 ) 556 ) 557 ) 558 ) { 559 if ( ! empty( $queried_object->taxonomy ) ) { 560 $classes[] = 'current-' . $queried_object->taxonomy . '-ancestor'; 561 } else { 562 $classes[] = 'current-' . $queried_object->post_type . '-ancestor'; 563 } 564 } 565 566 if ( in_array( (int) $parent_item->db_id, $active_ancestor_item_ids, true ) ) { 567 $classes[] = 'current-menu-ancestor'; 568 569 $menu_items[ $key ]->current_item_ancestor = true; 570 } 571 if ( in_array( (int) $parent_item->db_id, $active_parent_item_ids, true ) ) { 572 $classes[] = 'current-menu-parent'; 573 574 $menu_items[ $key ]->current_item_parent = true; 575 } 576 if ( in_array( (int) $parent_item->object_id, $active_parent_object_ids, true ) ) { 577 $classes[] = 'current-' . $active_object . '-parent'; 578 } 579 580 if ( 'post_type' === $parent_item->type && 'page' === $parent_item->object ) { 581 // Back compat classes for pages to match wp_page_menu(). 582 if ( in_array( 'current-menu-parent', $classes, true ) ) { 583 $classes[] = 'current_page_parent'; 584 } 585 if ( in_array( 'current-menu-ancestor', $classes, true ) ) { 586 $classes[] = 'current_page_ancestor'; 587 } 588 } 589 590 $menu_items[ $key ]->classes = array_unique( $classes ); 591 } 592 } 593 594 /** 595 * Retrieves the HTML list content for nav menu items. 596 * 597 * @uses Walker_Nav_Menu to create HTML list content. 598 * @since 3.0.0 599 * 600 * @param array $items The menu items, sorted by each menu item's menu order. 601 * @param int $depth Depth of the item in reference to parents. 602 * @param stdClass $r An object containing wp_nav_menu() arguments. 603 * @return string The HTML list content for the menu items. 604 */ 605 function walk_nav_menu_tree( $items, $depth, $r ) { 606 $walker = ( empty( $r->walker ) ) ? new Walker_Nav_Menu : $r->walker; 607 608 return $walker->walk( $items, $depth, $r ); 609 } 610 611 /** 612 * Prevents a menu item ID from being used more than once. 613 * 614 * @since 3.0.1 615 * @access private 616 * 617 * @param string $id 618 * @param object $item 619 * @return string 620 */ 621 function _nav_menu_item_id_use_once( $id, $item ) { 622 static $_used_ids = array(); 623 624 if ( in_array( $item->ID, $_used_ids, true ) ) { 625 return ''; 626 } 627 628 $_used_ids[] = $item->ID; 629 630 return $id; 631 }