Usually the identifier is the UUID of the object, but it could be an array of the identity properties, too.
See also: Neos\Flow\Persistence\PersistenceManagerInterface::getIdentifierByObject() Useful for using the identifier outside of the form view helpers (e.g. JavaScript and AJAX). = Examples = {post.blog -> f:format.identifier()} 97e7e90a-413c-44ef-b2d0-ddfa4387b5ca // depending on {post.blog} {identifier: '{someObject -> f:format.identifier()}'} {"identifier":"bf37f335-b273-4353-af77-fd8dc65cb66f"} // depending on the UUID of {someObject}
Inheritance: extends Neos\FluidAdaptor\Core\ViewHelper\AbstractViewHelper
 /**
  * @test
  * @expectedException \Neos\FluidAdaptor\Core\ViewHelper\Exception
  */
 public function renderThrowsExceptionIfGivenValueIsNoObject()
 {
     $notAnObject = array();
     $this->viewHelper->render($notAnObject);
 }