Filter By Term Not Working - Custom Post Type

Question

I have a custom post type called Listings. The listings has taxonomies which I want to use to filter down the results when viewing all of the listings in the admin area.

To do this I tried to use the following:

function my_restrict_manage_posts() {
    global $typenow;
    $args = array('public' => true, '_builtin' => false);
    $post_types = get_post_types($args);
    if (in_array($typenow, $post_types)) {
        $filters = get_object_taxonomies($typenow);
        foreach ($filters as $tax_slug) {
            $tax_obj = get_taxonomy($tax_slug);
            wp_dropdown_categories(array(
                'show_option_all' => __('Show All ' . $tax_obj->label),
                'taxonomy' => $tax_slug,
                'name' => $tax_obj->name,
                'orderby' => 'term_order',
                'selected' => $_GET[$tax_obj->query_var],
                'hierarchical' => $tax_obj->hierarchical,
                'show_count' => false,
                'hide_empty' => true
            ));
        }
    }
}

function my_convert_restrict($query) {
    global $pagenow;
    global $typenow;
    if ($pagenow == 'edit.php') {
        $filters = get_object_taxonomies($typenow);
        foreach ($filters as $tax_slug) {
            $var = & $query->query_vars[$tax_slug];
            if (isset($var)) {
                $term = get_term_by('id', $var, $tax_slug);
                $var = $term->slug;
            }
        }
    }
}

add_action('restrict_manage_posts', 'my_restrict_manage_posts');
add_filter('parse_query', 'my_convert_restrict');

I am then able to choose the option in the drop down and then press filter and I get a URL like /wp-admin/edit.php?s&post_status=all&post_type=listings&action=-1&m=0&make=149&filter_action=Filter&paged=1&action2=-1

So the ID is being passed but then when the page reloads, I still have all of the listings and the filter hasn't worked. Any suggestions if there is anything I have missed or if there are any errors?

Answer 1

I have realised the problem isn't with the code I have posted and the issue is when the taxonomies are being created.

Basically the reason this wasn't working is because the query_var parameter was set to false when registering the taxonomy. I changed this to true and my filtering started working.