yii\validators\ImageValidator::clientValidateAttribute PHP Метод

    public function clientValidateAttribute($model, $attribute, $view)
    {
        ValidationAsset::register($view);
        $options = $this->getClientOptions($model, $attribute);
        return 'yii.validation.image(attribute, messages, ' . json_encode($options, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE) . ', deferred);';
    }