public function __construct(field_collection $fields, collection $source_data)
{
$final_fields = [];
$this->source_data = $source_data;
$fields->iterate(function (filter $field) use(&$final_fields, $source_data) {
$values = $source_data->filter_unique($field);
$new_field = form::create('field_checkboxes', $field->inner_field()->field_name, $values);
$new_field->original_field = $field->inner_field();
$new_field->label = $field->title;
$final_fields[] = $new_field;
});
$final_fields[] = form::create('field_string', 'identifier')->set_attr('hidden', true);
parent::__construct($final_fields);
}
