As the sun rises and the forest mist clears, and the clouds return and the caves darken, these changes of light and shadow are the morning and evening in the mountains. Wildflowers bloom with their subtle fragrance, fine trees flourish with their dense shade, the wind and frost are pure and clean, and the water recedes to reveal the rocks—these are the four seasons in the mountains. Going out in the morning and returning in the evening, the scenery of the four seasons is different, and the joy is endless.至于负者歌于途,行者休于树,前者呼,后者应,伛偻提携,往来而不绝者,滁人游也。临溪而渔,溪深而鱼肥,酿泉为酒,泉香而酒洌,山肴野蔌,杂然而前陈者,太守宴也。宴酣之乐,非丝非竹,射者中,弈者胜,觥筹交错,起坐而喧哗者,众宾欢也。苍颜白发,颓然乎其间者,太守醉也。
<?php
/**
* Nav Menu API: Walker_Nav_Menu class
*
* @package WordPress
* @subpackage Nav_Menus
* @since 4.6.0
*/
/**
* Core class used to implement an HTML list of nav menu items.
*
* @since 3.0.0
*
* @see Walker
*/
class Walker_Nav_Menu extends Walker {
/**
* What the class handles.
*
* @since 3.0.0
* @var string
*
* @see Walker::$tree_type
*/
public $tree_type = array( 'post_type', 'taxonomy', 'custom' );
/**
* Database fields to use.
*
* @since 3.0.0
* @todo Decouple this.
* @var string[]
*
* @see Walker::$db_fields
*/
public $db_fields = array(
'parent' => 'menu_item_parent',
'id' => 'db_id',
);
/**
* The URL to the privacy policy page.
*
* @since 6.8.0
* @var string
*/
private $privacy_policy_url;
/**
* Constructor.
*
* @since 6.8.0
*/
public function __construct() {
$this->privacy_policy_url = get_privacy_policy_url();
}
/**
* 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 ) );
$atts = array();
$atts['class'] = ! empty( $class_names ) ? $class_names : '';
/**
* Filters the HTML attributes applied to a menu list element.
*
* @since 6.3.0
*
* @param array $atts {
* The HTML attributes applied to the `<ul>` element, empty strings are ignored.
*
* @type string $class HTML CSS class attribute.
* }
* @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_submenu_attributes', $atts, $args, $depth );
$attributes = $this->build_atts( $atts );
$output .= "{$n}{$indent}<ul{$attributes}>{$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>{$n}";
}
/**
* Starts the element output.
*
* @since 3.0.0
* @since 4.4.0 The {@see 'nav_menu_item_args'} filter was added.
* @since 5.9.0 Renamed `$item` to `$data_object` and `$id` to `$current_object_id`
* to match parent class for PHP 8 named parameter support.
* @since 6.7.0 Removed redundant title attributes.
*
* @see Walker::start_el()
*
* @param string $output Used to append additional content (passed by reference).
* @param WP_Post $data_object 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 $current_object_id Optional. ID of the current menu item. Default 0.
*/
public function start_el( &$output, $data_object, $depth = 0, $args = null, $current_object_id = 0 ) {
// Restores the more descriptive, specific name for use within this method.
$menu_item = $data_object;
if ( isset( $args->item_spacing ) && 'discard' === $args->item_spacing ) {
$t = '';
$n = '';
} else {
$t = "\t";
$n = "\n";
}
$indent = ( $depth ) ? str_repeat( $t, $depth ) : '';
$classes = empty( $menu_item->classes ) ? array() : (array) $menu_item->classes;
$classes[] = 'menu-item-' . $menu_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 $menu_item Menu item data object.
* @param int $depth Depth of menu item. Used for padding.
*/
$args = apply_filters( 'nav_menu_item_args', $args, $menu_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 $menu_item The current menu item object.
* @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 ), $menu_item, $args, $depth ) );
/**
* Filters the ID attribute applied to a menu item's list item element.
*
* @since 3.0.1
* @since 4.1.0 The `$depth` parameter was added.
*
* @param string $menu_item_id The ID attribute applied to the menu item's `<li>` element.
* @param WP_Post $menu_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-' . $menu_item->ID, $menu_item, $args, $depth );
$li_atts = array();
$li_atts['id'] = ! empty( $id ) ? $id : '';
$li_atts['class'] = ! empty( $class_names ) ? $class_names : '';
/**
* Filters the HTML attributes applied to a menu's list item element.
*
* @since 6.3.0
*
* @param array $li_atts {
* The HTML attributes applied to the menu item's `<li>` element, empty strings are ignored.
*
* @type string $class HTML CSS class attribute.
* @type string $id HTML id attribute.
* }
* @param WP_Post $menu_item The current menu item object.
* @param stdClass $args An object of wp_nav_menu() arguments.
* @param int $depth Depth of menu item. Used for padding.
*/
$li_atts = apply_filters( 'nav_menu_item_attributes', $li_atts, $menu_item, $args, $depth );
$li_attributes = $this->build_atts( $li_atts );
$output .= $indent . '<li' . $li_attributes . '>';
/** This filter is documented in wp-includes/post-template.php */
$title = apply_filters( 'the_title', $menu_item->title, $menu_item->ID );
// Save filtered value before filtering again.
$the_title_filtered = $title;
/**
* Filters a menu item's title.
*
* @since 4.4.0
*
* @param string $title The menu item's title.
* @param WP_Post $menu_item The current menu item object.
* @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, $menu_item, $args, $depth );
$atts = array();
$atts['target'] = ! empty( $menu_item->target ) ? $menu_item->target : '';
$atts['rel'] = ! empty( $menu_item->xfn ) ? $menu_item->xfn : '';
if ( ! empty( $menu_item->url ) ) {
if ( $this->privacy_policy_url === $menu_item->url ) {
$atts['rel'] = empty( $atts['rel'] ) ? 'privacy-policy' : $atts['rel'] . ' privacy-policy';
}
$atts['href'] = $menu_item->url;
} else {
$atts['href'] = '';
}
$atts['aria-current'] = $menu_item->current ? 'page' : '';
// Add title attribute only if it does not match the link text (before or after filtering).
if ( ! empty( $menu_item->attr_title )
&& trim( strtolower( $menu_item->attr_title ) ) !== trim( strtolower( $menu_item->title ) )
&& trim( strtolower( $menu_item->attr_title ) ) !== trim( strtolower( $the_title_filtered ) )
&& trim( strtolower( $menu_item->attr_title ) ) !== trim( strtolower( $title ) )
) {
$atts['title'] = $menu_item->attr_title;
} else {
$atts['title'] = '';
}
/**
* Filters the HTML attributes applied to a menu item's anchor element.
*
* @since 3.6.0
* @since 4.1.0 The `$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 $menu_item The current menu item object.
* @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, $menu_item, $args, $depth );
$attributes = $this->build_atts( $atts );
$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 $menu_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, $menu_item, $depth, $args );
}
/**
* Ends the element output, if needed.
*
* @since 3.0.0
* @since 5.9.0 Renamed `$item` to `$data_object` to match parent class for PHP 8 named parameter support.
*
* @see Walker::end_el()
*
* @param string $output Used to append additional content (passed by reference).
* @param WP_Post $data_object Menu item 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, $data_object, $depth = 0, $args = null ) {
if ( isset( $args->item_spacing ) && 'discard' === $args->item_spacing ) {
$t = '';
$n = '';
} else {
$t = "\t";
$n = "\n";
}
$output .= "</li>{$n}";
}
/**
* Builds a string of HTML attributes from an array of key/value pairs.
* Empty values are ignored.
*
* @since 6.3.0
*
* @param array $atts Optional. An array of HTML attribute key/value pairs. Default empty array.
* @return string A string of HTML attributes.
*/
protected function build_atts( $atts = array() ) {
$attribute_string = '';
foreach ( $atts as $attr => $value ) {
if ( false !== $value && '' !== $value && is_scalar( $value ) ) {
$value = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );
$attribute_string .= ' ' . $attr . '="' . $value . '"';
}
}
return $attribute_string;
}
}