Symfony2 -正则表达式验证

我需要创建字段，作为选项获得正则字符串。

所以，我创建了PatternType字段:

public function getDefaultOptions(array $options)
{
    $defaultOptions = array(
        'data'              => null,
        'data_class'        => null,
        'trim'              => true,
        'required'          => true,
        'read_only'         => false,
        'max_length'        => null,
        'pattern'           => null,
        'property_path'     => null,
        'by_reference'      => true,
        'error_bubbling'    => false,
        'regexp'            => false,
        'error_mapping'     => array(),
        'label'             => null,
        'attr'              => array(),
        'invalid_message'   => 'This value is not valid',
        'invalid_message_parameters' => array()
    );
    $class = isset($options['data_class']) ? $options['data_class'] : null;
    // If no data class is set explicitly and an object is passed as data,
    // use the class of that object as data class
    if (!$class && isset($options['data']) && is_object($options['data'])) {
        $defaultOptions['data_class'] = $class = get_class($options['data']);
    }
    if ($class) {
        $defaultOptions['empty_data'] = function () use ($class) {
            return new $class();
        };
    } else {
        $defaultOptions['empty_data'] = '';
    }

    $patt = $options['regexp'];
    unset($options['regexp']);
    $defaultOptions['validation_constraint'] = new Regex(
                                                      array(
                                                          'pattern' => $patt,
                                                          'match' => true,
                                                          'message' => 'Niewłaściwy format'
                                                           )
                                                        );

    var_dump($defaultOptions);

    return $defaultOptions;
}

var_dump返回格式良好的设置数组，其中包含regex对象-但是当表单生成验证不起作用时-传递任何值。知道为什么吗?