Incompatibility with Field collection

hi,

I now think that the issue is in the field collection module.

In function field_collection_field_widget_embed_validate of field_collection module (see code snippet below), it tests if there are errors in the form and not only the error coming from the validation of the field collection field. As we can have errors coming from required field hidden using conditional field, then the field collection is not saved. The trick is that conditional field module will manage (and clean) the errors relative to the dependents or the dependees but it is called at the end of the form validation process (in the function: conditional_fields_dependent_validate).

function field_collection_field_widget_embed_validate($element, &$form_state, $complete_form) {

  // .... 
  // Only if the form is being submitted, finish the collection entity and
  // prepare it for saving.
  if ($form_state['submitted'] && !form_get_errors()) {  // <---- HERE IS THE ISSUE
    //...
  }
}

So I rewrite this function in order to check only the errors coming from the field collection validation. I'm really sorry but I am not familiar with the patch process and I unfortunatly do not have time today to create a nice patch so here is the code I use now (and that solves my problem...)

function field_collection_field_widget_embed_validate($element, &$form_state, $complete_form) {
  $instance = field_widget_instance($element, $form_state);
  $field = field_widget_field($element, $form_state);
  $field_parents = $element['#field_parents'];
  $field_name = $element['#field_name'];
  $language = $element['#language'];

  $field_state = field_form_get_state($field_parents, $field_name, $language, $form_state);
  $field_collection_item = $field_state['entity'][$element['#delta']];

  // Attach field API validation of the embedded form.
  field_attach_form_validate('field_collection_item', $field_collection_item, $element, $form_state);

  // Variable to store the validation errors for the field collection
  // Errors are not directly set on the form to avoid compatibility issue with other modules
  // such as conditional_fields
  $field_collection_errors = array();
  // Now validate required elements if the entity is not empty.
  if (!field_collection_item_is_empty($field_collection_item) && !empty($element['#field_collection_required_elements'])) {
    foreach ($element['#field_collection_required_elements'] as &$elements) {

      // Copied from _form_validate().
      if (isset($elements['#needs_validation'])) {
        $is_empty_multiple = (!count($elements['#value']));
        $is_empty_string = (is_string($elements['#value']) && drupal_strlen(trim($elements['#value'])) == 0);
        $is_empty_value = ($elements['#value'] === 0);
        if ($is_empty_multiple || $is_empty_string || $is_empty_value) {
          if (isset($elements['#title'])) {
            $field_collection_errors[] = array('elements' => $elements,
              'message' => t('!name field is required.', array('!name' => $elements['#title'])),
            );
          }
          else {
            $field_collection_errors[] = array('elements' => $elements,
              'message' => '',
            );
          }
        }
      }
    }
  }

  // Only if the form is being submitted, finish the collection entity and
  // prepare it for saving.
  if ($form_state['submitted'] && sizeof($field_collection_errors) == 0) {

    field_attach_submit('field_collection_item', $field_collection_item, $element, $form_state);

    // Set the _weight if it is a multiple field.
    if (isset($element['_weight']) && ($field['cardinality'] > 1 || $field['cardinality'] == FIELD_CARDINALITY_UNLIMITED)) {
      $item['_weight'] = $element['_weight']['#value'];
    }

    // Put the field collection item in $item['entity'], so it is saved with
    // the host entity via hook_field_presave() / field API if it is not empty.
    // @see field_collection_field_presave()
    $item['entity'] = $field_collection_item;
    form_set_value($element, $item, $form_state);
  }

  // Add the errors to the form
  foreach ($field_collection_errors as $field_collection_error) {
    form_error($field_collection_error['elements'], $field_collection_error['message']);
  }
}

I will suggest a patch in the field condition module as soon as I have time (hopefully before the end of the week).

I close the ticket since it is not due to conditional field. Please follow #1549364: Data not being saved on initial creation for the patch.

@dufferin I am not sure your problem is identical to my issue, I suggest you create a new ticket for that.