Exclude current page in wp_list_pages

Question

I'm using wp_list_pages() to display a menu of child pages.

The structure is nice and simple. Looks like this: http://cl.ly/image/0w1Q1q2D3D18

The menu works perfectly when on a child page: http://cl.ly/image/3O310E0s2B3d

But, alas, does not work when on the parent page: http://cl.ly/image/3w0T3Q2s4347

Seems so simple, but i just can't get to the bottom of it.

Here's my wp_list_pages() code:

<?php

            $topmost_parent = $post->post_parent;

            $args = array(
                'post_type'    => 'guides', 
                'sort_column' => 'menu_order',
                'title_li'     => __(''),
                'echo' => 0, 
                'exclude' => $topmost_parent
                );

            $children = wp_list_pages( $args );

            if ($children) :
        ?>

            <nav id="menu-context">
                <ul class="menu">
                    <?php echo $children; ?>
                </ul>
            </nav>

        <?php endif;?>

Using that $topmost_parent trick works until I'm on the parent page. Anyone got a new trick? =)

Answer 1

Your code won't work if you have more than one parent page or multiple levels of child pages. Use get_ancestors to get the top parent page, and use the child_of argument of wp_list_pages rather than exclude to only output pages from that branch.

Answer 2

A more detailed explanation for those to follow.

You first need to sort out if the page you're looking at has ancestors. If it is a child page, it has an ancestors, if it's a parent page, it does not have an ancestor. This will determine that for you:

if (!$post->post_parent):
                    // will get the subpages of this top level page
                    $parent = $post->ID;
                elseif ($post->ancestors):
                    // now can get the the top ID of this page
                    // WordPress puts the IDs DESC, which is why the top level ID is the last one
                    $parent = end($post->ancestors);
                endif;

After that, you just need to use the $parent variable you just setup as the value in the child_of argument. Thusly:

$args_for_step_by_steps = array(
                'post_type'    => 'guides', 
                'sort_column' => 'menu_order',
                'title_li'     => __(''),
                'echo' => 0, 
                'child_of' => $parent
                ); 

And so the whole function then to get child pages only:

    <?php
        if (!$post->post_parent):
            // will get the subpages of this top level page
            $parent = $post->ID;
        elseif ($post->ancestors):
            // now can get the the top ID of this page
            // WordPress puts the IDs DESC, which is why the top level ID is the last one
            $parent = end($post->ancestors);
        endif;


        $args = array(
            'post_type'    => 'guides', 
            'sort_column' => 'menu_order',
            'title_li'     => __(''),
            'echo' => 0, 
            'child_of' => $parent
            );

        $children = wp_list_pages( $args );

        if ($children) :
    ?>



        <nav id="menu-context">
            <ul class="menu">
                <?php echo $children; ?>
            </ul>
        </nav>

    <?php endif;?>

Answer 3

Or ... create a primary menu like so:

if ( function_exists( 'register_nav_menus' ) ) {
    register_nav_menus( array( 'primary' => 'Primary Navigation' ) );
}

Then in the admin, go to Appearance > Menus and select the primary menu from the drop down menu. You just don't include the pages you don't want.