Multiple users – only allow them to manage their own terms for custom taxonomy when logged in

Question

How can I allow each user to manage their own terms for a custom taxonomy when logged in on edit-tags page? user will only show & manage terms that only created by him not others for a custom taxonomy. But Admin and editor can manage all. How can I do that?

Any help will be appreciated. Thanks.

Answer 1

Thanks for the AWESOME solution MikeSchinkel :D

I just did the following updates in the code and it worked like a charm:

add_filter('list_terms_exclusions', 'yoursite_list_terms_exclusions', 10, 2);

function yoursite_list_terms_exclusions( $exclusions ) {
    $currentScreen = get_current_screen();

    if( current_user_can( 'my_custom_capability_assigned_to_specific_users' )
            && !current_user_can( 'manage_options' ) // Show everything to Admin
            && is_object( $currentScreen )
            && $currentScreen->id == 'edit-<my_taxonomy>'
            && $currentScreen->taxonomy == '<my_taxonomy>' ) {
        // Get term_id's array that you want to show as per your requirement
        $terms      = implode( ',', $term_id );
        $exclusions = ( empty( $exclusions ) ? '' : $exclusions ) . ' AND' . ' t.`term_id` IN (' . $terms . ')';
    }
    return $exclusions;
}

Answer 2

Hmmm. You are going to need to keep track of who added which terms which you can currently best do in a usermeta field as a comma-separated list (I'm assuming you don't expect more than ~1000 terms per user? At lot more than then I'd worry.)

You can store the term IDs in the usermeta field using the 'edited_terms' hook as you see here:

• Any examples of adding custom fields to the category editor?

Basically your code might look like this"

add_filter('edited_terms', 'yoursite_edited_terms');
function yoursite_edited_terms($term_id) {
  if($_POST['taxonomy'] == 'your_taxonomy'): {
    $user = wp_get_current_user();
    if ($user->ID) {
      $terms = get_user_meta($user->ID,'users_terms_for_your_taxonomy');
      $terms = (empty($terms) ? $term_id : "{$terms},{$term_id}");
      update_user_meta($user->ID,'users_terms_for_your_taxonomy',$terms);
    }
  }
}

Then you'll need to use the 'list_terms_exclusions' hook to limit your terms to only the ones needed for the current user, but allowing the Administrator an Editor to see them all by adding a 'can_manage_all_terms' capability which you can use the Members plugin to create:

• How can I hide a category from Contributors in the edit/add new post screen?

Here's what that might look like:

add_filter('list_terms_exclusions', 'yoursite_list_terms_exclusions', 10, 2);
function yoursite_list_terms_exclusions( $exclusions, $args ) {
  global $pagenow;
  if (current_user_can('can_manage_all_terms') && 
    $pagenow=='edit-tags.php?taxonomy=your_post_taxonomy') {
    $terms = get_user_meta($user->ID,'users_terms_for_your_taxonomy');
    $exclusions = " {$exclusions} AND t.ID NOT IN ({$terms})";
  }
  return $exclusions;
}

I haven't tested this code but it should get you on the right track. And be sure to replace anything in the code written as 'your_taxonomy' with a reference to your actual taxonomy.