Twig_Environment::render PHP Method

    public function render($name, array $context = array())
    {
        return $this->loadTemplate($name)->render($context);
    }

 /**
  * {@inheritdoc}
  */
 public function validate($emailTemplate, Constraint $constraint)
 {
     /** @var EmailTemplate $emailTemplate */
     /** @var VariablesConstraint $constraint */
     $fieldsToValidate = array('subject' => $emailTemplate->getSubject(), 'content' => $emailTemplate->getContent());
     foreach ($emailTemplate->getTranslations() as $trans) {
         if (in_array($trans->getField(), array('subject', 'content'))) {
             $fieldsToValidate[$trans->getLocale() . '.' . $trans->getField()] = $trans->getContent();
         }
     }
     $relatedEntity = false;
     if (class_exists($emailTemplate->getEntityName())) {
         $className = $emailTemplate->getEntityName();
         $relatedEntity = new $className();
     }
     $errors = array();
     foreach ($fieldsToValidate as $field => $value) {
         try {
             $this->twig->render($value, array('entity' => $relatedEntity, 'user' => $this->getUser()));
         } catch (\Exception $e) {
             $errors[$field] = true;
         }
     }
     if (!empty($errors)) {
         $this->context->addViolation($constraint->message);
     }
 }