Dies ist der Walker, mit dem ich nur untergeordnete Elemente des aktuellen Menüelements angezeigt habe. Oder die Menüpunkte Geschwister, wenn es keine eigenen Kinder hat.
Es gibt Kommentare in der gesamten Klasse, die jeden Abschnitt erklären
<?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 );
}
}
Bringen Sie es wie bei jedem anderen benutzerdefinierten Walker in einem wp_nav_menu an
<?php
wp_nav_menu( array(
'menu' => 'primary-menu'
,'container' => 'nav'
,'container_class' => 'subpages'
,'depth' => 0
,'walker' => new SH_Child_Only_Walker()
));
?>