Remove some articles from the list in WPAdmin for a user

Question

I'd like to remove some posts shown for some users.

Here's the long problem explanation:

In my site, there are Groups. These groups can post blog posts, but only access blogposts made by their own chapter.

So I put a meta down for users and another in the posts, but now, in the posts list, I'd like to only show those where the 2 metas match.

So how can I remove some of the blog posts from the blog listing page in the Administration?

Answer 1

This could done with couple of ways:

With pre_get_posts Small modification will need it like the actual meta value names

function alter_edit_php_query_remove_posts($query) {
    $screen = get_current_screen();
    if(is_admin() && $screen->post_type == 'post') {

        $current_user = wp_get_current_user();
        $key = 'nickname';
        $single = true;
        $user_meta_value = get_user_meta( $current_user->ID, $key, $single); 

        $meta_query = array(
                        array(
                            'key'=>'_edit_last',
                            'value'=>$user_meta_value,
                            'compare'=>'=',
                        ),
        );
        $query->set('meta_query',$meta_query);
  }
}
add_action('pre_get_posts','alter_edit_php_query_remove_posts');

With map_meta_cap:

    add_filter('map_meta_cap', 'prevent_user_view_post', 3, 4 );
    function prevent_user_view_post( $required_caps, $cap, $user_id, $args ){   

        if( ( $cap=='read_post'|| $cap='edit_post') ){
            $post_id  = $args[0]??0;

            $post_meta_value=get_post_meta($post_id,'meta_key',true);
            $key = 'nickname';
            $single = true;
            $user_meta_value = get_user_meta( $user_id, $key, $single );
            $user_meta_value = 2;
            if ( $post_meta_value != $user_meta_value && $post_id ==1 ){
                $required_caps[] = 'do_not_allow';
            }

        }

        return $required_caps;

    }