Displaying category archive of custom post types

Question

I am woefully late to the party on Custom Post Types and only started using them quite recently, so apologies if my questions seems idiotic, but I can't seem to find an answer to my question.

I've set up a custom post type called actors with a couple of custom field values, and (crucially), I'm using standard categories to separate these actors into men, women and children listings:

'taxonomies' => array('category', 'post_tag')

...since I thought that would be a much cleaner and neater way of... well, categorizing the actors. However, I'm completely stumped at how to actually display these categories in any way, shape or form.

I have a custom archive-actors.php file which displays all of the actors, but I want to be able to filter them by category; e.g. only display the men. However if I guess at a standard URL like mysite.com/category/actors/men I just get

Sorry, but there aren't any posts in the Men category yet.

The same thing happens if I just try mysite.com/category/men - in neither case is it using the archive-actors.php template, either.

Can anyone help clear away my fog of dull-mindedness and point me in the right direction so I can filter out these pesky actors?

Edit:

As @mrwweb alludes to below (and I forgot to mention I had tried), the following can be added to the functions.php file:

function query_post_type($query) {
    $post_types = get_post_types();

    if ( is_category() || is_tag()) {

        $post_type = get_query_var('actors');

        if ( $post_type ) {
            $post_type = $post_type;
        } else {
            $post_type = $post_types;
        }

        $query->set('post_type', $post_type);

        return $query;
    }
}

add_filter('pre_get_posts', 'query_post_type');

...as referenced here which does work, insofar as it will display my categorised custom post types on the regular archive.php page, but doesn't utilise my archive-actors.php, which is key.

Answer 1

You can force use of your template for categories with the category_template filter:

function wpa57439_category_template( $templates = '' ){
    if( !is_array( $templates ) && !empty( $templates ) ) {
        $templates = locate_template( array( 'archive-actors.php', $templates ), false );
    } 
    elseif( empty( $templates ) ) {
        $templates = locate_template( 'archive-actors.php', false );
    }
    else {
        $new_template = locate_template( array( 'archive-actors.php' ) );
        if( !empty( $new_template ) ) array_unshift( $templates, $new_template );
    }
    return $templates;
}
add_filter( 'category_template', 'wpa57439_category_template' );

adapted from Filter Hierarchy in codex.

Answer 2

That's the expected behavior of category archives. As found here on the Support forums the following snippet should resolve your issue (just change "article" to your post type):

add_filter('pre_get_posts', 'query_post_type');
function query_post_type($query) {
  if(is_category() || is_tag()) {
    $post_type = get_query_var('post_type');
    if($post_type)
        $post_type = $post_type;
    else
        $post_type = array('post','articles','nav_menu_item');
    $query->set('post_type',$post_type);
    return $query;
    }
}

UPDATE: Gah. I grabbed the wrong snippet. I meant to use this one.

Answer 3

Alternatively, what you can do is just add a new wp_rewrite rule to create a new url structure for displaying only posts in a given cpt and category. Something like the .gist I posted here:

[edit: can't embed .gists so here's the code and linky ]

/**
* This could be extrapolated and used for tags or any other taxonomy really.
*/

add_action('init', 'category_cpt_rewrites');

function category_cpt_rewrites() {
    $custom_post_types = array('video', 'audio', 'photo', 'file'); //some example post types
    foreach ( $custom_post_types as $post_type ) {
        $rule = '^' . $post_type . '/category/(.+?)/?$';
        $rewrite = 'index.php?post_type=' . $post_type . '&category_name=$matches[1]';
        add_rewrite_rule($rule,$rewrite,'top');
    }
}

//make sure you flush rules
//this will take the following url structure (video cpt as an example, and politics as a category example) -> video/category/politics and return posts belonging to the politics category that are in the "video" custom post type.

//note that if you want this to be truly effective you'll want to make a custom "the_category()" or similar template function to return the correct url structure for a category list belonging to a custom post type post.