How to stop node form validation after AHAH

Question

I have using Drupal 6 and AHAH to customize my node form. For ahah I use this code:

function mymodule_subtopic_type() {
    $output = '';

    $form_state = array('storage' => null, 'submitted' => false, 'rebuild' => true);
    $form_build_id = $_POST['form_build_id'];

    $form = form_get_cache($form_build_id, $form_state);

    $args = $form['#parameters'];
    $form_id = array_shift($args);
    $form_state['post'] = $_POST;
    $form['#post'] = $_POST;
    $form['#programmed'] = false;

    $form['#redirect'] = false;

    drupal_process_form($form_id, $form, $form_state);

    $form = drupal_rebuild_form($form_id, $form_state, $args, $form_build_id);

    $topic_form = $form['topic_wrapper'];
    unset($topic_form['#prefix'], $topic_form['#suffix']);
    $output .= theme('status_messages');
    $output .= drupal_render($topic_form);

    drupal_json(array('status' => TRUE, 'data' => $output));
}

New form elements are rendered fine, but I get status messages:

• Title field is required.
• Description field is required.

How to stop validation after ahah call?

Answer 1

Solution from d.o.: http://drupal.org/node/831900#comment-3124386

Add this function:

 function _ahah_helper_disable_validation(&$form) {
   foreach (element_children($form) as $child) {
     $form[$child]['#validated'] = TRUE;
     _ahah_helper_disable_validation(&$form[$child]);
   }
 }

and call it before drupal_process_form($form_id, $form, $form_state);