How do I override field_multiple_value_form()?

Question

I have to override the standard field wrappers which add additional divs.

Drupal uses the following code, in field_multiple_value_form().

$field_elements += array(
  '#theme' => 'field_multiple_value_form',
  '#field_name' => $field['field_name'],
  '#cardinality' => $field['cardinality'],
  '#title' => $title,
  '#required' => $instance['required'],
  '#description' => $description,
  '#prefix' => '<div id="' . $wrapper_id . '">',
  '#suffix' => '</div>',
  '#max_delta' => $max,
); 

I implemented hook_form_alter(), but this form needs extra data that are passed as argument: $field, $instance, $langcode, $items, $form, and $form_state.

How do I define hook_form_alter() in this case?

Answer 1

You need to implement hook_field_widget_form_alter(), which is invoked from field_multiple_value_form() using the following code.

  $element = array(
    '#entity_type' => $instance['entity_type'], 
    '#entity' => $form['#entity'], 
    '#bundle' => $instance['bundle'], 
    '#field_name' => $field_name, 
    '#language' => $langcode, 
    '#field_parents' => $parents, 
    '#columns' => array_keys($field['columns']),
    // For multiple fields, title and description are handled by the wrapping table. 
    '#title' => $multiple ? '' : $title, 
    '#description' => $multiple ? '' : $description,
    // Only the first widget should be required. 
    '#required' => $delta == 0 && $instance['required'], 
    '#delta' => $delta, 
    '#weight' => $delta,
  );
  if ($element = $function($form, $form_state, $field, $instance, $langcode, $items, $delta, $element)) {
    // Input field for the delta (drag-n-drop reordering).
    if ($multiple) {
      // We name the element '_weight' to avoid clashing with elements
      // defined by widget.
      $element['_weight'] = array(
        '#type' => 'weight', 
        '#title' => t('Weight for row @number', array('@number' => $delta + 1)), 
        '#title_display' => 'invisible',
        // Note: this 'delta' is the FAPI 'weight' element's property. 
        '#delta' => $max, 
        '#default_value' => isset($items[$delta]['_weight']) ? $items[$delta]['_weight'] : $delta, 
        '#weight' => 100,
      );
    }

    // Allow modules to alter the field widget form element.
    $context = array(
      'form' => $form, 
      'field' => $field, 
      'instance' => $instance, 
      'langcode' => $langcode, 
      'items' => $items, 
      'delta' => $delta,
    );
    drupal_alter(array('field_widget_form', 'field_widget_' . $instance['widget']['type'] . '_form'), $element, $form_state, $context);

    $field_elements[$delta] = $element;
  }

For example, you could implement it using the following code.

function mymodule_field_widget_form_alter(&$element, &$form_state, $context) {
  $element['#prefix'] = $element['#suffix'] = '';
}

The arguments passed to field_multiple_value_form() are also passed to hook_field_widget_form_alter(), directly, or contained in $context.