自定义验证webform Drupal

Question

I am trying to understand how I can put some custom validation to a Drupal webform.

I've understand that I have to put some function somewhere, but I can't understand where .Somebody says that I have to put my custom code in the module webform, in a hook, but what file ? Someone else said that I have to put my code in the template.php file of the template.

Example of the code that I think I have to implement :

    function starting_drupal_dev_form_alter(&$form, &$form_state, $form_id) {
  if ($form_id == 'article_node_form') {
    $form['#validate'][] = 'starting_drupal_dev_form_validate';
    dpm($form['#validate']);
  }
} 

I have found this example on internet : drupal form validation But it's very confusing.

Can anyone clarify this ? I'm using Drupal 7.43.

Answer 1

Ok, so the answer to my problem was to put the form_alter function in the mymodule.module file.