Implements the magic __toString() method.
Overrides AttributeValueBase::__toString
File
 
   - drupal/core/lib/Drupal/Core/Template/AttributeString.php, line 30
- Definition of Drupal\Core\Template\AttributeString.
Class
  
  - AttributeString 
- A class that represents most standard HTML attributes.
Namespace
  Drupal\Core\Template
Code
public function __toString() {
  $this->printed = TRUE;
  return check_plain($this->value);
}