start_lvl ignored in custom walker_nav_menu

Question

This is my first project involving wordpress and i've got stuck trying to create a custom walker for a footer menu.

I basically want to change the menu from the <ul> <li></li> </ul> structure to a <p> <span></span> </p> structure.

The menu and stuff is displaying file and I have been able to adjust the start_el and end_el functions without issue so I now get this:

<ul> <span>*link*</span> <span>*link*</span> </ul>

Which is obviously half way there, I have written the start_lvl() and end_lvl() tags as shown below but they are ignored by wordpress - nothing I put in them (even die()) is executed (which is a bit suspicious) but I know the class is being called because of the start_el() function.

function start_lvl(&$output, $depth = 0, $args = array()) {
    $output = "\n<p class=\"sub-menu\">\n";
}

function end_lvl(&$output, $depth = 0, $args = array()) {
    $output .= "\n</p>\n";
}

Does anyone know why this is happening - have I missed something really obvious!?

I am running the latest version of wordpress on apache with php 5.3.6 if it helps.

Thanks in advance,

Felix :)

Answer 1

Ok, not sure what I read wrong when I posted this, but your whole class should be something like this:

class my_extended_walker extends Walker_Nav_Menu {
    function start_lvl(&$output, $depth = 0, $args = array()) {
        $output .= "\n<p class=\"sub-menu\">\n";
    }

    function end_lvl(&$output, $depth = 0, $args = array()) {
        $output .= "\n</p>\n";
    }
}

And then pass the 'walker' as a parameter when you call wp_nav_menu

wp_nav_menu( array( 'walker'=>new my_extended_walker() ) );

If you've got that you should be fine. I am looking at working code that does just that. I don't know about putting <p> tags in there though. You may get invalid markup.

Answer 2

Have you thought about fetching all of the navigation menu items using the built-in function: wp_get_nav_menu_items(); and manually outputting the contents?

Example :: Building simple menu list

    // Get the nav menu based on $menu_name (same as 'theme_location' or 'menu' arg to wp_nav_menu)
    // This code based on wp_nav_menu's code to get Menu ID from menu slug

    $menu_name = 'custom_menu_slug';

    if ( ( $locations = get_nav_menu_locations() ) && isset( $locations[ $menu_name ] ) ) {
    $menu = wp_get_nav_menu_object( $locations[ $menu_name ] );

    $menu_items = wp_get_nav_menu_items($menu->term_id);

    $menu_list = '<ul id="menu-' . $menu_name . '">';

    foreach ( (array) $menu_items as $key => $menu_item ) {
        $title = $menu_item->title;
        $url = $menu_item->url;
        $menu_list .= '<li><a href="' . $url . '">' . $title . '</a></li>';
    }
    $menu_list .= '</ul>';
    } else {
    $menu_list = '<ul><li>Menu "' . $menu_name . '" not defined.</li></ul>';
    }
    // $menu_list now ready to output