How do I know if a menu item has children or is a leaf?

  • Hi there!

    I’m developing a new theme and I need to mark menu items without children differently from “leaf” (no children) ones. Ideally with a css class for the “parents” – has-children, or similar. This is how my walker code looks now:


    class My_Walker_Nav_Menu extends Walker_Nav_Menu {
    function start_el(&$output, $item, $depth, $args) {
    ...
    if(??? $item has children???) {
    // I know what to do here
    }
    }
    }

    What should I put between the ???s ?

    Thanks and regards!

    PS: This question is also in StackOverflow and has a bounty of 100 rep points. Please feel free to answer there and I will gladly grant you those points.

Viewing 7 replies - 1 through 7 (of 7 total)
  • Moderator keesiemeijer

    (@keesiemeijer)

    Maybe this: https://www.ads-software.com/support/topic/wp_nav_menu-add-a-parent-class?replies=7

    Thread Starter otikik

    (@otikik)

    Hmm. I see. So he can’t do it in start_el, he uses the display_element instead. That looks like a possible answer. Thanks!

    PS: please feel free to post that link to the SO question as an answer.

    Hi! I also had a similar problem and figured out just before ??

    The Solution:

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

  $parents = array();
  if ( ( $locations = get_nav_menu_locations() ) && isset( $locations[ $args->theme_location ] ) ) {
    $menu = wp_get_nav_menu_object( $locations[ $args->theme_location ] );
    $menu_items = wp_get_nav_menu_items($menu->term_id);
    foreach( $menu_items as $menu_item ) {
      if( $menu_item->menu_item_parent != 0 )
        $parents[] = $menu_item->menu_item_parent;
    }
  }

  $dropdown = ''; $dropdown_toggle = ''; $caret = '';
  if( in_array($item->ID, $parents ) ) {
    $dropdown = ' dropdown';
    $dropdown_toggle = ' dropdown-toggle';
    $caret = ' <b class="caret"></b>';
  }

  $active = $item->current ? ' active' : '';

  [...]

    The important point is → if( in_array($item->ID, $parents ) ) { ... }
    I hope that will be useful for you…

    Please Note: In fact, we need only has_children property in $item variable.

    I used the following:

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

	// Has children
	$children = get_posts(array('post_type' => 'nav_menu_item', 'nopaging' => true, 'numberposts' => 1, 'meta_key' => '_menu_item_menu_item_parent', 'meta_value' => $item->ID));
	if (empty($children)) {
		$classes[] = 'no_children';
	}

	[...]

    Hope this is of use.

    This is a good idea!
    Based on this code can also be used as follows:

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

  global $wpdb;
  $children_count = $wpdb->get_var(
    $wpdb->prepare("
      SELECT COUNT(*) FROM $wpdb->postmeta
      WHERE meta_key = %s
      AND meta_value = %d
    ", '_menu_item_menu_item_parent', $item->ID)
  );

  if( $children_count > 0 ) {
    $dropdown = ' dropdown';
    $dropdown_toggle = ' dropdown-toggle';
    $caret = ' <b class="caret"></b>';
  }

  [...]

    I don’t like the already posted solutions (except the accepted one on SO), since they issue A LOT of queries to the database, although the necessary data is already available.

    class MyWalker extends Walker_Nav_Menu
{
    function display_element ($element, &$children_elements, $max_depth, $depth = 0, $args, &$output)
    {
        // check, whether there are children for the given ID and append it to the element with a (new) ID
        $element->hasChildren = isset($children_elements[$element->ID]) && !empty($children_elements[$element->ID]);

        return parent::display_element($element, $children_elements, $max_depth, $depth, $args, $output);
    }

    function start_el(&$output, $item, $depth, $args)
    {
        global $wp_query;

        // you know can access $item->hasChildren to do anything you want..
    }
}

    Honestly, you’re right.

    I just tried to solve the problem by using the start_el function.

    Your solution is more accurate because the performance is more important. Thank you for correcting.

Viewing 7 replies - 1 through 7 (of 7 total)
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