Profile: charlotteM-2

Problem: I have two custom post types, Trainers and Trainings, that are connected in a one-to-many relationship. Multiple Trainers can be associated with the same Training post. Each Trainer post is associated with only one User, who is the post author, and each User can only create one Trainer post. Each User can create multiple Training posts. I would like to automatically associate a new Training post created with Forms to the same post author's Trainer post.

Solution:
Use the cred_save_data API to add functionality whenever a new Training post is created. Use the WP get_posts method to determine the post author's Trainer post, and if it exists, use the toolset_connect_posts API to connect the Training and Trainer posts:

add_action('cred_save_data', 'ts_link_author_trainer_to_training',10,2);
function ts_link_author_trainer_to_training($post_id, $form_data)
{
  global $current_user;
  wp_get_current_user();
  // if a specific form
  if ($form_data['id']==541)
  {
    // get the Training post created by the current User
    $trainer_args = array(
      'post_type'=>'trainer',
      'numberposts'=>1,
      'author'=>$current_user->ID,
    );
    $trainer_res = get_posts( $trainer_args );
    if(isset($trainer_res[0])) {
      $trainer = $trainer_res[0];
      // connect the trainer and the training just created by Forms
      toolset_connect_posts( 'trainer-activiteit', $trainer->ID, $post_id );
    }
  }
}

Relevant Documentation:
https://toolset.com/documentation/programmer-reference/cred-api/#cred_save_data
https://toolset.com/documentation/customizing-sites-using-php/post-relationships-api/#toolset_connect_posts