1

I am trying to create custom menu nav walker. I added below code

function display_element( $element, &$children_elements, $max_depth, $depth=0, $args, &$output )
{
    $id_field = $this->db_fields['id'];
    if ( is_object( $args[0] ) ) {
        $args[0]->has_children = ! empty( $children_elements[$element->$id_field] );
    }
    return parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );
}

As a result I can use if ( $args->has_children ) statement in my start_el function, unfortunately the same code doesn't seem to be working in end_el function.

Entire code:

class CSS_Menu_Walker2 extends Walker {
  /**
   * What the class handles.
   *
   * @see Walker::$tree_type
   * @since 3.0.0
   * @var string
   */
  public $tree_type = array( 'post_type', 'taxonomy', 'custom' );

  /**
   * Database fields to use.
   *
   * @see Walker::$db_fields
   * @since 3.0.0
   * @todo Decouple this.
   * @var array
   */
  public $db_fields = array( 'parent' => 'menu_item_parent', 'id' => 'db_id' );

  /**
   * Starts the list before the elements are added.
   *
   * @see Walker::start_lvl()
   *
   * @since 3.0.0
   *
   * @param string $output Passed by reference. Used to append additional content.
   * @param int    $depth  Depth of menu item. Used for padding.
   * @param array  $args   An array of arguments. @see wp_nav_menu()
   */
  public function start_lvl( &$output, $depth = 0, $args = array() ) {
    $indent = str_repeat("\t", $depth);
    $output .= "\n$indent <div class=\"collapsible-body\"> <ul class=\"sub-menu\">\n";
  }

  /**
   * Ends the list of after the elements are added.
   *
   * @see Walker::end_lvl()
   *
   * @since 3.0.0
   *
   * @param string $output Passed by reference. Used to append additional content.
   * @param int    $depth  Depth of menu item. Used for padding.
   * @param array  $args   An array of arguments. @see wp_nav_menu()
   */
  public function end_lvl( &$output, $depth = 0, $args = array() ) {
    $indent = str_repeat("\t", $depth);

    $output .= "$indent</ul></div>\n";
  }

  /**
   * Start the element output.
   *
   * @see Walker::start_el()
   *
   * @since 3.0.0
   *
   * @param string $output Passed by reference. Used to append additional content.
   * @param object $item   Menu item data object.
   * @param int    $depth  Depth of menu item. Used for padding.
   * @param array  $args   An array of arguments. @see wp_nav_menu()
   * @param int    $id     Current item ID.
   */


    function display_element( $element, &$children_elements, $max_depth, $depth=0, $args, &$output )
    {
        $id_field = $this->db_fields['id'];
        if ( is_object( $args[0] ) ) {
            $args[0]->has_children = ! empty( $children_elements[$element->$id_field] );
        }
        return parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );
    }



  public function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {


    $indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

    $classes = empty( $item->classes ) ? array() : (array) $item->classes;
    $classes[] = 'menu-item-' . $item->ID;

    /**
     * Filter the CSS class(es) applied to a menu item's list item element.
     *
     * @since 3.0.0
     * @since 4.1.0 The `$depth` parameter was added.
     *
     * @param array  $classes The CSS classes that are applied to the menu item's `<li>` element.
     * @param object $item    The current menu item.
     * @param array  $args    An array of {@see wp_nav_menu()} arguments.
     * @param int    $depth   Depth of menu item. Used for padding.
     */
    $class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args, $depth ) );
    $class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';

    /**
     * Filter 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 object $item    The current menu item.
     * @param array  $args    An array of {@see 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 ) . '"' : '';

    if ( $args->has_children ) {
    $output .= $indent .  '<ul class="collapsible collapsible-accordion">';
    $output .= $indent . '<a class="collapsible-header  waves-effect waves-teal ">';
    }
    $output .= $indent . '<li' . $id . $class_names .'>';

    $atts = array();
    $atts['title']  = ! empty( $item->attr_title ) ? $item->attr_title : '';
    $atts['target'] = ! empty( $item->target )     ? $item->target     : '';
    $atts['rel']    = ! empty( $item->xfn )        ? $item->xfn        : '';
    $atts['href']   = ! empty( $item->url )        ? $item->url        : '';

    /**
     * Filter 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.
     * }
     * @param object $item  The current menu item.
     * @param array  $args  An array of {@see 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 ( ! empty( $value ) ) {
        $value = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );
        $attributes .= ' ' . $attr . '="' . $value . '"';
      }
    }

    $item_output = $args->before;
    if (!$args->has_children ) 
    $item_output .= '<a'. $attributes .'>';
    /** This filter is documented in wp-includes/post-template.php */
    $item_output .= $args->link_before . apply_filters( 'the_title', $item->title, $item->ID ) . $args->link_after;
    if (!$args->has_children ) 
    $item_output .= '</a>';
    $item_output .= $args->after;



    /**
     * Filter 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 object $item        Menu item data object.
     * @param int    $depth       Depth of menu item. Used for padding.
     * @param array  $args        An array of {@see wp_nav_menu()} arguments.
     */
    $output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );

  }

  /**
   * Ends the element output, if needed.
   *
   * @see Walker::end_el()
   *
   * @since 3.0.0
   *
   * @param string $output Passed by reference. Used to append additional content.
   * @param object $item   Page data object. Not used.
   * @param int    $depth  Depth of page. Not Used.
   * @param array  $args   An array of arguments. @see wp_nav_menu()
   */
  public function end_el( &$output, $item, $depth = 0, $args = array() ) {

    $output .= "</li>\n";

  }

} // Walker_Nav_Menu
?>
a

Am I doing something wrong?

1
  • What I noticed is that when I print_r $args in start_el and end_el , has_children is set only in start_el. How can I ensure that same $args are passed to end_el ? Commented Aug 17, 2015 at 10:55

3 Answers 3

3

I have the same issue. Some answers claim that you can use $args->has_children or $args[0]->has_children, but it's never added to $args. Sometimes, has_children is added under $args->walker->has_children, but it's always set to false, in other words, useless...

As a work around, the current template that I'm using adds a class to items that contain children (menu-item-has-children), so I searched for it under $item->classes.

function end_el( &$output, $item, $depth = 0, $args = array() ) {

    if( !empty($item->classes) && 
        is_array($item->classes) && 
        in_array('menu-item-has-children', $item->classes) ){

        // This guy has children

    }
}

I guess, you could add a mark in your start_el function and then search for it...

I hope this helps. If you have a better solutions, please share it.

1

Here's a one-liner that checks the $children_elements for the existence of the $element->ID as a top-level array key and is, therefore, a parent.

$is_parent = array_key_exists( $element->ID, $children_elements );

EDIT: I should have mentioned this must be used in Walker method display_element so to use this you would add the method to your custom walker class as follows:

class Your_Custom_Walker extends Walker_Nav_Menu {

    public function display_element( $element, &$children_elements, $max_depth, $depth = 0, $args, &$output ) {

        $is_parent = array_key_exists( $element->ID, $children_elements );

        //do stuff with $is_parent

    }
}

If you're not already using the display_element method then this 'one-liner' starts to look more cumbersome. This method makes iterating over and manipulating the menu tree a little easier as it happens before being passed to start_el and gives you access to $children_elements.

0

Just an update that the display_element() is not actually needed (perhaps any more). You can now do:

public function start_el( &$output, $data_object, $depth = 0, $args = array(), $current_object_id = 0 ) {
    // Your existing code here.

    // Check if the current menu item has children.
    if ( isset( $args->walker->has_children ) && $args->walker->has_children ) {
        // Do something when this item has child menu items.
    }
}

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