WordPress: permalink rewrite for custom post type category archive

Question

I have a custom post type resource. This custom post type shares the category taxonomy with posts.

For a given category term archive, example url: /category/reducing-inequality/, I want to have an additional URL that displays ONLY the resource custom post type for that category. I can do so by using a query string:

category/reducing-inequality/?post_type=resource

What I want to do though is create a rewrite rule that will have this category archive (the above URL) instead rewrite to /resource/category/reducing-inequality

Is this possible? Any guidance is much appreciated, thank you!

Answer 1

This is exactly what add_rewrite_rule() is for. I'd do something like:

function custom_resource_rewrite_rules() {
    add_rewrite_rule('^(\w+)/category/([A-Za-z0-9\-\_]+)/?', 'category/$matches[2]/?post_type=$matches[1]', 'top');
}
add_action('init', 'custom_resource_rewrite_rules');

You could, of course, pass resource to the rewrite directly...but the above is a more general solution that will work for any custom post type.

Note: You'll likely have to head to the WP-Admin and re-save your permalinks to properly "flush" them, in order for this to work.