Класс ядра который генерирует HTML код списка элементов навигационного меню WordPress. См. wp_nav_menu().
Использование
$walker = new Walker_Nav_Menu; $args = array( 'walker' => $walker, // ... другие параметры меню ); wp_nav_menu( $args );
Методы
Примеры
#1 Пример Создания своего HTML кода для wp_nav_menu()
Пример расширения класса Walker_Nav_Menu, для создания своего произвольного HTML кода который выводится функцией wp_nav_menu(). Наш HTML код будет написан специально для нашей темы.
Ниже код своего произвольного класса, который строит меню. Он добавляет глубину меню и четные/нечетные CSS классы к элементам меню (обоим ul и li):
Чтобы не изобретать велосипед, копируем код класса Walker_Nav_Menu{} и просто изменяем его как нам нужно.
// свой класс построения меню:
class My_Walker_Nav_Menu extends Walker_Nav_Menu {
// add classes to ul sub-menus
function start_lvl( &$output, $depth ) {
// depth dependent classes
$indent = ( $depth > 0 ? str_repeat( "\t", $depth ) : '' ); // code indent
$display_depth = ( $depth + 1); // because it counts the first submenu as 0
$classes = array(
'sub-menu',
( $display_depth % 2 ? 'menu-odd' : 'menu-even' ),
( $display_depth >=2 ? 'sub-sub-menu' : '' ),
'menu-depth-' . $display_depth
);
$class_names = implode( ' ', $classes );
// build html
$output .= "\n" . $indent . '<ul class="' . $class_names . '">' . "\n";
}
// add main/sub classes to li's and links
function start_el( &$output, $item, $depth, $args ) {
global $wp_query;
$indent = ( $depth > 0 ? str_repeat( "\t", $depth ) : '' ); // code indent
// depth dependent classes
$depth_classes = array(
( $depth == 0 ? 'main-menu-item' : 'sub-menu-item' ),
( $depth >=2 ? 'sub-sub-menu-item' : '' ),
( $depth % 2 ? 'menu-item-odd' : 'menu-item-even' ),
'menu-item-depth-' . $depth
);
$depth_class_names = esc_attr( implode( ' ', $depth_classes ) );
// passed classes
$classes = empty( $item->classes ) ? array() : (array) $item->classes;
$class_names = esc_attr( implode( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item ) ) );
// build html
$output .= $indent . '<li id="nav-menu-item-'. $item->ID . '" class="' . $depth_class_names . ' ' . $class_names . '">';
// link attributes
$attributes = ! empty( $item->attr_title ) ? ' title="' . esc_attr( $item->attr_title ) .'"' : '';
$attributes .= ! empty( $item->target ) ? ' target="' . esc_attr( $item->target ) .'"' : '';
$attributes .= ! empty( $item->xfn ) ? ' rel="' . esc_attr( $item->xfn ) .'"' : '';
$attributes .= ! empty( $item->url ) ? ' href="' . esc_attr( $item->url ) .'"' : '';
$attributes .= ' class="menu-link ' . ( $depth > 0 ? 'sub-menu-link' : 'main-menu-link' ) . '"';
$item_output = sprintf( '%1$s<a%2$s>%3$s%4$s%5$s</a>%6$s',
$args->before,
$attributes,
$args->link_before,
apply_filters( 'the_title', $item->title, $item->ID ),
$args->link_after,
$args->after
);
// build html
$output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
}
}
Теперь, когда класс готов, используем его в функции wp_nav_menu(). Для этого нужно указать экземпляр нашего класса в параметре walker.
function my_nav_menu( $args ) {
$args = array_merge( [
'container' => 'div',
'container_id' => 'top-navigation-primary',
'container_class' => 'top-navigation',
'menu_class' => 'menu main-menu menu-depth-0 menu-even',
'echo' => false,
'items_wrap' => '<ul id="%1$s" class="%2$s">%3$s</ul>',
'depth' => 10,
'walker' => new My_Walker_Nav_Menu()
], $args );
echo wp_nav_menu( $args );
}Теперь там, где нужно выводить меню используем нашу функцию:
my_nav_menu( [ 'theme_location' => 'navigation_menu_primary' ] );
Заметки
- Смотрите: Walker
Список изменений
class Walker_Nav_Menu extends Walker {
/**
* What the class handles.
*
* @since 3.0.0
* @var string
*
* @see Walker::$tree_type
*/
public $tree_type = array( 'post_type', 'taxonomy', 'custom' );
/**
* Database fields to use.
*
* @since 3.0.0
* @todo Decouple this.
* @var array
*
* @see Walker::$db_fields
*/
public $db_fields = array(
'parent' => 'menu_item_parent',
'id' => 'db_id',
);
/**
* 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 ) );
$class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';
$output .= "{$n}{$indent}<ul$class_names>{$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.
*
* @see Walker::start_el()
*
* @param string $output Used to append additional content (passed by reference).
* @param WP_Post $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.
* @param int $id Current item ID.
*/
public function start_el( &$output, $item, $depth = 0, $args = null, $id = 0 ) {
if ( isset( $args->item_spacing ) && 'discard' === $args->item_spacing ) {
$t = '';
$n = '';
} else {
$t = "\t";
$n = "\n";
}
$indent = ( $depth ) ? str_repeat( $t, $depth ) : '';
$classes = empty( $item->classes ) ? array() : (array) $item->classes;
$classes[] = 'menu-item-' . $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 $item Menu item data object.
* @param int $depth Depth of menu item. Used for padding.
*/
$args = apply_filters( 'nav_menu_item_args', $args, $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 $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.
*/
$class_names = implode( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args, $depth ) );
$class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';
/**
* Filters the ID applied to a menu item's list item element.
*
* @since 3.0.1
* @since 4.1.0 The `$depth` parameter was added.
*
* @param string $menu_id The ID that is applied to the menu item's `<li>` element.
* @param WP_Post $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-' . $item->ID, $item, $args, $depth );
$id = $id ? ' id="' . esc_attr( $id ) . '"' : '';
$output .= $indent . '<li' . $id . $class_names . '>';
$atts = array();
$atts['title'] = ! empty( $item->attr_title ) ? $item->attr_title : '';
$atts['target'] = ! empty( $item->target ) ? $item->target : '';
if ( '_blank' === $item->target && empty( $item->xfn ) ) {
$atts['rel'] = 'noopener';
} else {
$atts['rel'] = $item->xfn;
}
$atts['href'] = ! empty( $item->url ) ? $item->url : '';
$atts['aria-current'] = $item->current ? 'page' : '';
/**
* Filters the HTML attributes applied to a menu item's anchor element.
*
* @since 3.6.0
* @since 4.1.0 The `$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 $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.
*/
$atts = apply_filters( 'nav_menu_link_attributes', $atts, $item, $args, $depth );
$attributes = '';
foreach ( $atts as $attr => $value ) {
if ( is_scalar( $value ) && '' !== $value && false !== $value ) {
$value = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );
$attributes .= ' ' . $attr . '="' . $value . '"';
}
}
/** This filter is documented in wp-includes/post-template.php */
$title = apply_filters( 'the_title', $item->title, $item->ID );
/**
* Filters a menu item's title.
*
* @since 4.4.0
*
* @param string $title The menu item's title.
* @param WP_Post $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.
*/
$title = apply_filters( 'nav_menu_item_title', $title, $item, $args, $depth );
$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 $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, $item, $depth, $args );
}
/**
* Ends the element output, if needed.
*
* @since 3.0.0
*
* @see Walker::end_el()
*
* @param string $output Used to append additional content (passed by reference).
* @param WP_Post $item Page 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, $item, $depth = 0, $args = null ) {
if ( isset( $args->item_spacing ) && 'discard' === $args->item_spacing ) {
$t = '';
$n = '';
} else {
$t = "\t";
$n = "\n";
}
$output .= "</li>{$n}";
}
}