How to set up an rss feed in WP?

Question

RSS

It is necessary to make sure that not all entries are added to the rss feed. Namely, from the admin panel, if the user checks the box "Add to rss" when adding news, then this news will be added to rss, otherwise the news will not be published there. How can this be implemented? (tick made with ACF)

Answer 1

Try it:

function add_to_rss($query) {
  if (is_admin()) {
    return $query;
  }
  $include = array();
  if ( $query->is_main_query() && is_feed() ) {
      $posts = get_posts(array(
        'post_type' => 'post',
        'meta_query' => array(
          array(
            'key' => 'добавить_в_rss',
            'value' => '1',
            'compare' => '=',
          ),
        ),
      ));
      foreach($posts as $post) {
        $include[] = $post->ID;
      }
      $query->set('post__in', $include);
    }
  return $query;
}
add_filter( 'pre_get_posts', 'add_to_rss' );

You need to paste it in functions.php .
add_to_rss is the name of the field in the ACF.