array( self::STANDARD => '{{name}} must be a valid date', self::FORMAT => '{{name}} must be a valid date. Sample format: {{format}}', ), self::MODE_NEGATIVE => array( self::STANDARD => '{{name}} must not be a valid date', self::FORMAT => '{{name}} must not be a valid date in the format {{format}}', ), ); public function configure($name, array $params = array()) { $params['format'] = date( $params['format'], strtotime('2005-12-30 01:02:03') ); return parent::configure($name, $params); } public function chooseTemplate() { return $this->getParam('format') ? static::FORMAT : static::STANDARD; } }