public function columnFormat($attribute, $model = null)
{
if ($model === null) {
$model = $this->modelClass;
}
$code = $this->callProviderQueue(__FUNCTION__, $attribute, $model, $this);
if ($code !== null) {
Yii::trace("found provider for '{$attribute}'", __METHOD__);
} else {
$code = $this->shorthandAttributeFormat($attribute, $model);
Yii::trace("using standard formatting for '{$attribute}'", __METHOD__);
}
return $code;
}