Checkboxes options with class in form api

Question

I need something like a filter on checkboxes #options in my form built via Form API. Is there a way to group checkboxes or add a class to filter them via js front side?

In the documentation options are simply 'value' => 'label'. Can I filter or group them?

Answer 1

To modify how drupal outputs checkboxes, override the default theme_checkbox function found in includes/form.inc. This allow to you add classes and all other stuff. I simply copied the function and changed the last 8 lines:

/* Override theme_checkbox to display titles as facebook-style beautytips  */
function MYTHEME_checkbox($variables) {
  $element = $variables['element'];
  $element['#attributes']['type'] = 'checkbox';
  element_set_attributes($element, array('id', 'name', '#return_value' => 'value'));

  // Unchecked checkbox has #value of integer 0.
  if (!empty($element['#checked'])) {
    $element['#attributes']['checked'] = 'checked';
  }
  _form_set_class($element, array('form-checkbox'));

  if (substr($element['#name'],0, 13) == "field_MYFIELD") :
    $element['#attributes']['class'][] = 'beautytips';
    return 
      '<input title="' . $element['#title'] .'" ' . 
      drupal_attributes($element['#attributes']) . ' />';
  else: // Return the regular value
    return '<input ' . drupal_attributes($element['#attributes']) . ' />';
  endif;
}

Thanks @clive for the inspirtation.

Answer 2

If you want to display check boxes options as optgroup, then Drupal already provide this functionality. You need to set multidimensional array for #options field.

Example:

$options = = array (

   'parent1' => array(
      3 => 'child1',
      4 => 'child2',
      5 => 'child3',
    ),
    'parent2' => array(
      8 => 'child1',
      9 => 'child2',
    ),
);


$form['FIELDNAME'] = array(
    '#type' => 'checkboxes',
    '#title' => 'Checkbox'
    '#options' => $options,
);