Counting top level items in a custom menu walker

Question

I am creating a split menu (half the items on the left, logo in the middle, remaining items on the right). I don't really understand Walkers all that well, but I found this code snippet.

This was working well for me until my client wanted to add child items. The current code is counting all the menu items (10) when I want it to just count the top level items (currently 7).

How do I adjust this code so that it only counts the top level items?

class Split_Menu_Walker extends Walker_Nav_Menu {

    var $current_menu = null;
    var $break_point  = null;

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

        global $wp_query;

        if( !isset( $this->current_menu ) )
            $this->current_menu = wp_get_nav_menu_object( $args->menu );

        if( !isset( $this->break_point ) )
            $this->break_point = ceil( $this->current_menu->count / 2 ) + 1;

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

        $class_names = $value = '';

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

        $class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args ) );
        $class_names = ' class="' . esc_attr( $class_names ) . '"';

        $id = apply_filters( 'nav_menu_item_id', 'menu-item-'. $item->ID, $item, $args );
        $id = strlen( $id ) ? ' id="' . esc_attr( $id ) . '"' : '';

        if( $this->break_point == $item->menu_order )
            $output .= $indent . '</li></ul><ul><li' . $id . $value . $class_names .'>';
        else
            $output .= $indent . '<li' . $id . $value . $class_names .'>';

        $attributes  = ! empty( $item->attr_title ) ? ' title="'  . esc_attr( $item->attr_title ) .'"' : '';
        $attributes .= ! empty( $item->target )     ? ' target="' . esc_attr( $item->target     ) .'"' : '';
        $attributes .= ! empty( $item->xfn )        ? ' rel="'    . esc_attr( $item->xfn        ) .'"' : '';
        $attributes .= ! empty( $item->url )        ? ' href="'   . esc_attr( $item->url        ) .'"' : '';

        $item_output = $args->before;
        $item_output .= '<a'. $attributes .'>';
        $item_output .= $args->link_before . apply_filters( 'the_title', $item->title, $item->ID ) . $args->link_after;
        $item_output .= '</a>';
        $item_output .= $args->after;

        $output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
    }
}

Answer 1

Calculation you talking about going here:

if( !isset( $this->break_point ) )
        $this->break_point = ceil( $this->current_menu->count / 2 ) + 1;

You can't get top-level items count this way. Instead you should count it yourself. You can do this using wp_get_nav_menu_items(). Every top-level item should have menu_item_parent set to '0'.

You should create additional variable where you calculate already displayed elements. So top of your file should looks like this:

class Split_Menu_Walker extends Walker_Nav_Menu {

    public $break_point = null;
    public $displayed = 0; 

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

    global $wp_query;

    if( !isset( $this->break_point ) ) {
        $menu_elements = wp_get_nav_menu_items( $args->menu );
        $top_level_elements = 0;

        foreach( $menu_elements as $el ) {
            if( $el->menu_item_parent === '0' ) {
                $top_level_elements++;
            }
        }
        $this->break_point = ceil( $top_level_elements / 2 ) + 1;
     }   


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

Then you should increment $this->displayed++; every time you display top level element (for example at the end of start_el() function):

if( $item->menu_item_parent === '0' ) {
    $this->displayed++;
}

Lastly instead of

if( $this->break_point == $item->menu_order ) 

you should use

if( $this->break_point == $this->displayed )