wp_nav_menu

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Summery Summery

Displays a navigation menu.

Syntax Syntax

wp_nav_menu( array $args = array() )

Parameters Parameters

$args

(Optional) Array of nav menu arguments.

  • 'menu'
    (int|string|WP_Term) Desired menu. Accepts a menu ID, slug, name, or object.
  • 'menu_class'
    (string) CSS class to use for the ul element which forms the menu. Default 'menu'.
  • 'menu_id'
    (string) The ID that is applied to the ul element which forms the menu. Default is the menu slug, incremented.
  • 'container'
    (string) Whether to wrap the ul, and what to wrap it with. Default 'div'.
  • 'container_class'
    (string) Class that is applied to the container. Default 'menu-{menu slug}-container'.
  • 'container_id'
    (string) The ID that is applied to the container.
  • 'fallback_cb'
    (callable|bool) If the menu doesn't exist, a callback function will fire. Default is 'wp_page_menu'. Set to false for no fallback.
  • 'before'
    (string) Text before the link markup.
  • 'after'
    (string) Text after the link markup.
  • 'link_before'
    (string) Text before the link text.
  • 'link_after'
    (string) Text after the link text.
  • 'echo'
    (bool) Whether to echo the menu or return it. Default true.
  • 'depth'
    (int) How many levels of the hierarchy are to be included. 0 means all. Default 0.
  • 'walker'
    (object) Instance of a custom walker class.
  • 'theme_location'
    (string) Theme location to be used. Must be registered with register_nav_menu() in order to be selectable by the user.
  • 'items_wrap'
    (string) How the list items should be wrapped. Default is a ul with an id and class. Uses printf() format with numbered placeholders.
  • 'item_spacing'
    (string) Whether to preserve whitespace within the menu's HTML. Accepts 'preserve' or 'discard'. Default 'preserve'.

Default value: array()

Return Return

(void|string|false) Void if 'echo' argument is true, menu output if 'echo' is false. False if there are no items or no menu was found.

Source Source

File: wp-includes/nav-menu-template.php

 *     @type string             $items_wrap           How the list items should be wrapped. Uses printf() format with
 *                                                    numbered placeholders. Default is a ul with an id and class.
 *     @type string             $item_spacing         Whether to preserve whitespace within the menu's HTML.
 *                                                    Accepts 'preserve' or 'discard'. Default 'preserve'.
 * }
 * @return void|string|false Void if 'echo' argument is true, menu output if 'echo' is false.
 *                           False if there are no items or no menu was found.
 */
function wp_nav_menu( $args = array() ) {
	static $menu_id_slugs = array();

	$defaults = array(
		'menu'                 => '',
		'container'            => 'div',
		'container_class'      => '',
		'container_id'         => '',
		'container_aria_label' => '',
		'menu_class'           => 'menu',
		'menu_id'              => '',
		'echo'                 => true,
		'fallback_cb'          => 'wp_page_menu',
		'before'               => '',
		'after'                => '',
		'link_before'          => '',
		'link_after'           => '',
		'items_wrap'           => '<ul id="%1$s" class="%2$s">%3$s</ul>',
		'item_spacing'         => 'preserve',
		'depth'                => 0,
		'walker'               => '',
		'theme_location'       => '',
	);

	$args = wp_parse_args( $args, $defaults );

	if ( ! in_array( $args['item_spacing'], array( 'preserve', 'discard' ), true ) ) {
		// Invalid value, fall back to default.
		$args['item_spacing'] = $defaults['item_spacing'];
	}

	/**
	 * Filters the arguments used to display a navigation menu.
	 *
	 * @since 3.0.0
	 *
	 * @see wp_nav_menu()
	 *
	 * @param array $args Array of wp_nav_menu() arguments.
	 */
	$args = apply_filters( 'wp_nav_menu_args', $args );
	$args = (object) $args;

	/**
	 * Filters whether to short-circuit the wp_nav_menu() output.
	 *
	 * Returning a non-null value from the filter will short-circuit wp_nav_menu(),
	 * echoing that value if $args->echo is true, returning that value otherwise.
	 *
	 * @since 3.9.0
	 *
	 * @see wp_nav_menu()
	 *
	 * @param string|null $output Nav menu output to short-circuit with. Default null.
	 * @param stdClass    $args   An object containing wp_nav_menu() arguments.
	 */
	$nav_menu = apply_filters( 'pre_wp_nav_menu', null, $args );

	if ( null !== $nav_menu ) {
		if ( $args->echo ) {
			echo $nav_menu;
			return;
		}

		return $nav_menu;
	}

	// Get the nav menu based on the requested menu.
	$menu = wp_get_nav_menu_object( $args->menu );

	// Get the nav menu based on the theme_location.
	$locations = get_nav_menu_locations();
	if ( ! $menu && $args->theme_location && $locations && isset( $locations[ $args->theme_location ] ) ) {
		$menu = wp_get_nav_menu_object( $locations[ $args->theme_location ] );
	}

	// Get the first menu that has items if we still can't find a menu.
	if ( ! $menu && ! $args->theme_location ) {
		$menus = wp_get_nav_menus();
		foreach ( $menus as $menu_maybe ) {
			$menu_items = wp_get_nav_menu_items( $menu_maybe->term_id, array( 'update_post_term_cache' => false ) );
			if ( $menu_items ) {
				$menu = $menu_maybe;
				break;
			}
		}
	}

	if ( empty( $args->menu ) ) {
		$args->menu = $menu;
	}

	// If the menu exists, get its items.
	if ( $menu && ! is_wp_error( $menu ) && ! isset( $menu_items ) ) {
		$menu_items = wp_get_nav_menu_items( $menu->term_id, array( 'update_post_term_cache' => false ) );
	}

	/*
	 * If no menu was found:
	 *  - Fall back (if one was specified), or bail.
	 *
	 * If no menu items were found:
	 *  - Fall back, but only if no theme location was specified.
	 *  - Otherwise, bail.
	 */
	if ( ( ! $menu || is_wp_error( $menu ) || ( isset( $menu_items ) && empty( $menu_items ) && ! $args->theme_location ) )
		&& isset( $args->fallback_cb ) && $args->fallback_cb && is_callable( $args->fallback_cb ) ) {
			return call_user_func( $args->fallback_cb, (array) $args );
	}

	if ( ! $menu || is_wp_error( $menu ) ) {
		return false;
	}

	$nav_menu = '';
	$items    = '';

	$show_container = false;
	if ( $args->container ) {
		/**
		 * Filters the list of HTML tags that are valid for use as menu containers.
		 *
		 * @since 3.0.0
		 *
		 * @param string[] $tags The acceptable HTML tags for use as menu containers.
		 *                       Default is array containing 'div' and 'nav'.
		 */
		$allowed_tags = apply_filters( 'wp_nav_menu_container_allowedtags', array( 'div', 'nav' ) );

		if ( is_string( $args->container ) && in_array( $args->container, $allowed_tags, true ) ) {
			$show_container = true;
			$class          = $args->container_class ? ' class="' . esc_attr( $args->container_class ) . '"' : ' class="menu-' . $menu->slug . '-container"';
			$id             = $args->container_id ? ' id="' . esc_attr( $args->container_id ) . '"' : '';
			$aria_label     = ( 'nav' === $args->container && $args->container_aria_label ) ? ' aria-label="' . esc_attr( $args->container_aria_label ) . '"' : '';
			$nav_menu      .= '<' . $args->container . $id . $class . $aria_label . '>';
		}
	}

	// Set up the $menu_item variables.
	_wp_menu_item_classes_by_context( $menu_items );

	$sorted_menu_items        = array();
	$menu_items_with_children = array();
	foreach ( (array) $menu_items as $menu_item ) {
		$sorted_menu_items[ $menu_item->menu_order ] = $menu_item;
		if ( $menu_item->menu_item_parent ) {
			$menu_items_with_children[ $menu_item->menu_item_parent ] = true;
		}
	}

	// Add the menu-item-has-children class where applicable.
	if ( $menu_items_with_children ) {
		foreach ( $sorted_menu_items as &$menu_item ) {
			if ( isset( $menu_items_with_children[ $menu_item->ID ] ) ) {
				$menu_item->classes[] = 'menu-item-has-children';
			}
		}
	}

	unset( $menu_items, $menu_item );

	/**
	 * Filters the sorted list of menu item objects before generating the menu's HTML.
	 *
	 * @since 3.1.0
	 *
	 * @param array    $sorted_menu_items The menu items, sorted by each menu item's menu order.
	 * @param stdClass $args              An object containing wp_nav_menu() arguments.
	 */
	$sorted_menu_items = apply_filters( 'wp_nav_menu_objects', $sorted_menu_items, $args );

	$items .= walk_nav_menu_tree( $sorted_menu_items, $args->depth, $args );
	unset( $sorted_menu_items );

	// Attributes.
	if ( ! empty( $args->menu_id ) ) {
		$wrap_id = $args->menu_id;
	} else {
		$wrap_id = 'menu-' . $menu->slug;

		while ( in_array( $wrap_id, $menu_id_slugs, true ) ) {
			if ( preg_match( '#-(\d+)$#', $wrap_id, $matches ) ) {
				$wrap_id = preg_replace( '#-(\d+)$#', '-' . ++$matches[1], $wrap_id );
			} else {
				$wrap_id = $wrap_id . '-1';
			}
		}
	}
	$menu_id_slugs[] = $wrap_id;

	$wrap_class = $args->menu_class ? $args->menu_class : '';

	/**
	 * Filters the HTML list content for navigation menus.
	 *
	 * @since 3.0.0
	 *
	 * @see wp_nav_menu()
	 *
	 * @param string   $items The HTML list content for the menu items.
	 * @param stdClass $args  An object containing wp_nav_menu() arguments.
	 */
	$items = apply_filters( 'wp_nav_menu_items', $items, $args );
	/**
	 * Filters the HTML list content for a specific navigation menu.
	 *
	 * @since 3.0.0
	 *
	 * @see wp_nav_menu()
	 *
	 * @param string   $items The HTML list content for the menu items.
	 * @param stdClass $args  An object containing wp_nav_menu() arguments.
	 */
	$items = apply_filters( "wp_nav_menu_{$menu->slug}_items", $items, $args );

	// Don't print any markup if there are no items at this point.
	if ( empty( $items ) ) {
		return false;
	}

	$nav_menu .= sprintf( $args->items_wrap, esc_attr( $wrap_id ), esc_attr( $wrap_class ), $items );
	unset( $items );

	if ( $show_container ) {
		$nav_menu .= '</' . $args->container . '>';
	}

	/**
	 * Filters the HTML content for navigation menus.
	 *
	 * @since 3.0.0
	 *
	 * @see wp_nav_menu()
	 *

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Changelog Changelog

Changelog
Version Description
4.7.0 Added the item_spacing argument.
3.0.0 Introduced.

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