This is the walker I used to display only children of the current menu item. Or the menu items siblings if it doesn’t have any children of its own.
There are comments throughout the class explaining each section
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 | <?php class SH_Child_Only_Walker extends Walker_Nav_Menu { private $ID; private $depth; private $classes = array(); private $child_count = 0; private $have_current = false; // Don't start the top level function start_lvl(&$output, $depth=0, $args=array()) { if( 0 == $depth || $this->depth != $depth ) return; parent::start_lvl($output, $depth,$args); } // Don't end the top level function end_lvl(&$output, $depth=0, $args=array()) { if( 0 == $depth || $this->depth != $depth ) return; parent::end_lvl($output, $depth,$args); } // Don't print top-level elements function start_el(&$output, $item, $depth=0, $args=array()) { $is_current = in_array('current-menu-item', $this->classes); if( 0 == $depth || ! $is_current ) return; parent::start_el($output, $item, $depth, $args); } function end_el(&$output, $item, $depth=0, $args=array()) { if( 0 == $depth ) return; parent::end_el($output, $item, $depth, $args); } // Only follow down one branch function display_element( $element, &$children_elements, $max_depth, $depth=0, $args, &$output ) { // Check if element is in the current tree to display $current_element_markers = array( 'current-menu-item', 'current-menu-parent', 'current-menu-ancestor' ); $this->classes = array_intersect( $current_element_markers, $element->classes ); // If element has a 'current' class, it is an ancestor of the current element $ancestor_of_current = !empty($this->classes); // check if the element is the actual page element we are on. $is_current = in_array('current-menu-item', $this->classes); // if it is the current element if($is_current) { // set the count / ID / and depth to use in the other functions. $this->child_count = ( isset($children_elements[$element->ID]) ) ? count($children_elements[$element->ID]) : 0; $this->ID = $element->ID; $this->depth = $depth; $this->have_current = true; if($this->child_count > 0) { // if there are children loop through them and display the kids. foreach( $children_elements[$element->ID] as $child ) { parent::display_element( $child, $children_elements, $max_depth, $depth, $args, $output ); } } else { // no children so loop through kids of parent item. foreach( $children_elements[$element->menu_item_parent] as $child ) { parent::display_element( $child, $children_elements, $max_depth, $depth, $args, $output ); } } } // if depth is zero and not in current tree go to the next element if ( 0 == $depth && !$ancestor_of_current) return; // if we aren't on the current element proceed as normal if(! $this->have_current ) parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output ); } } |
Attach it like you would with any other custom walker on a wp_nav_menu
1 2 3 4 5 6 7 8 9 | <?php wp_nav_menu( array( 'menu' => 'primary-menu' ,'container' => 'nav' ,'container_class' => 'subpages' ,'depth' => 0 ,'walker' => new SH_Child_Only_Walker() )); ?> |
If you like this question & answer and want to contribute, then write your question & answer and email to freewebmentor[@]gmail.com. Your question and answer will appear on FreeWebMentor.com and help other developers.
