重建表单后将忽略drupal 7文本字段#default_value

Question

NOTE: I'm a drupal newbie. I'm developing a module based on the ajax examples: add_more and autocomplete. The idea is to have a form where I can add visitors to a visit, persons being entered in the texfield populated by an LDAP connection using ajax. This works fine.

The problem is that I want to be able to remove any visitor I want (not just the last one).

I have a add visitor button that adds a fieldset containing the textfield for the visitor name and a suppress button (sorry, no image, my reputation is too low) for this visitor. This means 3 visitors, 3 fieldsets with its 'suppress' button

When the user clicks on the suppress button of a visitor, I remove it, and call for a rebuild of the form but then, Drupal keeps displaying the first names as if I had suppressed the last one.

function gaz_edit_visit_form($form, &$form_state) {
    [...]
  // Build the fieldset with the proper number of names. We'll use
  // $form_state['num_names'] to determine the number of textfields to build.
  if (empty($form_state['num_names'])) {
    $form_state['num_names'] = 1;

    $form['visitors_fieldset']['name'][0] = array(
      '#type' => 'fieldset',
      '#title' => 'Visiteur 1'
    );

    $form['visitors_fieldset']['name'][0]['visitor'] = array(
      '#type' => 'textfield',
      '#title' => t('Nom du visiteur'),
      '#autocomplete_path' => 'gaz/visit/edit_visit_autocomplete_callback',
    );

    $form['visitors_fieldset']['add_name'] = array(
      '#type' => 'submit',
      '#value' => t('Ajouter un visiteur'),
      '#submit' => array('ajax_example_add_more_add_one2'),
      '#ajax' => array(
        'callback' => 'ajax_example_add_more_callback2',
        'wrapper' => 'visitors-fieldset-wrapper',
      ),
    );
  }
  else {
    for ($i = 0; $i < $form_state['num_names']; $i++) {
      $form['visitors_fieldset']['name'][$i] = array(
        '#type' => 'fieldset',
        '#title' => 'Visiteur ' . ($i + 1),
      );

      $form['visitors_fieldset']['name'][$i]['visitor'] = array(
        '#type' => 'textfield',
        '#title' => t('Nom du visiteur'),
        '#autocomplete_path' => 'gaz/visit/edit_visit_autocomplete_callback',
        '#default_value' => $form_state['values']['visitors_fieldset']['name'][$i]['visitor'],
      );

      if ($form_state['num_names'] > 1) {
        $form['visitors_fieldset']['name'][$i]['remove_visitor' . $i] = array(
          '#type' => 'submit',
          '#value' => t('Supprimer'),
          '#submit' => array('gaz_visitors_remove'),
          '#ajax' => array(
            'callback' => 'ajax_example_add_more_callback2',
            'wrapper' => 'visitors-fieldset-wrapper',
          ),
          '#gaz_visitor_index' => $i,
        );
      }

      $form['visitors_fieldset']['add_name'] = array(
        '#type' => 'submit',
        '#value' => t('Ajouter un visiteur'),
        '#submit' => array('ajax_example_add_more_add_one2'),
        '#ajax' => array(
          'callback' => 'ajax_example_add_more_callback2',
          'wrapper' => 'visitors-fieldset-wrapper',
        ),
      );
    }
  }

  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Confirm'),
  );

  return $form;
}

Here is the function that removes a particular user in the list.

function gaz_visitors_remove($form, &$form_state) {
  array_splice($form_state['values']['visitors_fieldset']['name'], $form_state['triggering_element']['#gaz_visitor_index'], 1);
  if ($form_state['num_names'] > 1) {
    $form_state['num_names']--;
  }
  $form_state['rebuild'] = TRUE;
}

The $form at the end of the rebuild process (ie end of the gaz_edit_visit_form function) seems ok, including the default_values of the textfields but drupal fills them with other values. If I have 3 visitors and then remove visitor 2, I expect to see names for 1 and 3 but I see names for 1 and 2. Again, $form... looks good and has no trace of user 2 anymore.

I guess I'm missing the huge elephant right before my eyes but I can't see it!

Answer 1

Try and go over this tutorial, https://drupal.org/node/717722 . The way you created your form is wrong and that's why doesn't remove what you want.

Answer 2

When Drupal does an AJAX rebuild, its order of execution is:

• build the form in the state that you submitted
• validate form stuff
• execute stuff (call your #submit handler - I think)
• rebuild the form for display
• return the output (call your ajax #callback)

$form_state['values'] is built in the first step. If you want to use it in the 4th step, as you do... then that's fine, but you need to keep this in mind.

It explains why your deleted visitor data is still in there. You have (num+1) visitors in $form_state['values']

How to work around that? It depends how you want to change your code, that's up to you. one way would be to have two counters, of which the second is the same as $i but at one point it can increment 1 extra, to skip the deleted value: (untested code)

$i2 = -1;
for (...) {
  $i2++;
  if (!empty($form_state['#triggering_element']) && $form_state['#triggering_element']['#value'] == t('Supprimer') && $form_state['#triggering_element']['#gaz_visitor_index'] == $i) {
    // OK, we pressed this button to delete a visitor, this one has been deleted so skip it.
    $i2++
  }
  ...
    '#default_value' => $form_state['values']['visitors_fieldset']['name'][$i2]['visitor']
  ...