Page that 'subscribes' to multiple categories

Question

I'm creating a website where I need to 'subscribe' client Pages to certain categories.

For example:

On example.com/client/johnson-co/ show all posts in the categories 'GST', 'Estate' and 'Tax General'.

On example.com/client/smith-co/ show all posts in the categories 'GST', 'Insurance' and 'Personal'.

I'm not at all attached to using Pages if there's a better way :) I do however need the categories 'subscribed' to to be editable using WordPress admin; not hard-coded into the theme.

---

I've researched and experimented with the following methods to no avail:

• Giving a category multiple parents (currently not possible in WP) - this would let me give category gst a parent of johnson-co and smith-co
• Using query_posts() and including cat=x (as per the codex) - this works but is hard coded and doesn't let someone subscribe a page to categories in the admin.
• Using custom post type (set up using CCTM plugin) so /client/johnson-co/ has checkbox meta fields of GST, Estate, Insurance, Personal etc. This is the closest but I couldn't get the link between what was checked and the categories showing working, and it feels like a bit of an ugly hack.

Would hugely really appreciate any ideas!

Answer 1

Enable the category taxonomy for your custom post type, or enable it for the default page post type:

function wpa_cats_for_pages(){
    register_taxonomy_for_object_type( 'category', 'page' );
}
add_action( 'init', 'wpa_cats_for_pages' );

Then within your page template, get the category IDs assigned to the client page and create a new query which passes those IDs:

// get IDs of categories assigned to this client page
$categories = wp_get_object_terms( $post->ID, 'category', array( 'fields' => 'ids' ) );

// query for posts with categories that match those assigned to this page
$args = array(
    'posts_per_page' => -1, // get all matching posts
    'category__in' => $categories
);

$client_posts = new WP_Query( $args );

// output post data
while( $client_posts->have_posts() ):
    $client_posts->the_post();
    the_title();
endwhile;

// reset the global $post object so template tags for this page work as expected
wp_reset_postdata();

Then for each client page, you'll just select the categories of posts you want displayed on that page, the same way you assign categories to the posts.