Restrict Access to Posts based on Custom User and Post Meta Data

In a similar use case scenario, I had a client with 5 locations which could be assigned to the user. This will need to be changed for you because it’s based on location being assigned to both a user and a post, whereas you’re just going to assigning entire posts to users rather than matching post meta.

function filter_by_user_club( $query ) {
  if( is_admin() ) {
    $user_id        = get_current_user_id();
    $user_location  = get_user_meta( $user_id, 'myplugin_user_location', true );
    $currentscreen  = get_current_screen();
    if ( $currentscreen->post_type == 'custom_post_type' ) {
        if( !empty( $user_location ) ) {
            $location_meta_query = array(
                'key'   => 'cpt_location',
                'value' => $user_location,
                'compare'   => 'IN'
            );
            $query->set('meta_query', array( $location_meta_query ) );
        }
    }
  }
add_action( 'pre_get_posts', 'filter_by_user_club', 9998 );

I’m guessing that this sort of modification would need to be applied for your method, if I’m understanding your structure correctly…

You would need to change the meta_query to instead query an array of IDs using post_in, like so:

    function filter_by_user_club( $query ) {
      if( is_admin() ) {
        $user_id        = get_current_user_id();
        $user_clubs     = get_user_meta( $user_id, 'myplugin_user_clubs', true );
        $currentscreen  = get_current_screen();
        if ( $currentscreen->post_type == 'club_post_type' ) {
            if( !empty( $user_clubs ) ) {
                //if you've saved the user club IDs as an array (recommended)
                $query->set('post_in', $user_clubs );
                //if you've saved the user club IDs as a string use this...
                //$query->set('post_in', array( $user_clubs ) );
            }
        }
      }
    add_action( 'pre_get_posts', 'filter_by_user_club', 9998 );

Obviously a lot still to do to get the club IDs associated with the user, etc. but this will filter the club post type list based on the user.

We’re using $query->set() and essentially adding an argument into that screen’s default get_posts() query. While the query here, by default, will grab all of the posts (paginated based on how many you set per screen), we’re now telling it to only show posts_in the array we provided when we checked which clubs a user has associated with them.