[TYPO3-mvc] New Property Mapper / persisting nested form objects

[Alexander Dick]

Hi everybody!

I am using Extbase 1.4, with the new property mapper enabled.

Persisting my nested form basically works, as I set 
allowCreationForSubProperty() in the corresponding initializeAction:

public function initializeSaveAction() {
		
	$this->arguments['parentObject']
		->getPropertyMappingConfiguration()
		->allowCreationForSubProperty('childObject');
		
}

BUT only if the childObject has a 1:1 relation with the parentObject / 
is no Tx_Extbase_Persistence_ObjectStorage!

If I have a m:m relation between ParentObject and the childObject it 
throws the well known "Exception while property mapping at property path 
"childObjects.0":Creation of objects not allowed. To enable this, you 
need to set the PropertyMappingConfiguration Value 
"CONFIGURATION_CREATION_ALLOWED" to TRUE"

So what can I do about this?

Relevant model properties:

class Tx_Xxx_Domain_Model_ParentObject extends 
Tx_Extbase_DomainObject_AbstractEntity {

	/**
	 * Simple child object - everything works as expected
	 * @var Tx_Xxx_Domain_Model_ChildObject
	 */
	protected $childObject;

	/**
	 * Multiple child objects - Exception...
	 *
	 * @var 
Tx_Extbase_Persistence_ObjectStorage<Tx_Xxx_Domain_Model_ChildObject>
	 */
	protected $childObjects;

}

In case of the "array" of child objects,
my initializeAction looks like this:

public function initializeSaveAction() {
	
	// does not have any effect - exception is thrown	
	$this->arguments['parentObject']
		->getPropertyMappingConfiguration()
		->allowCreationForSubProperty('childObjects');


	// has no effect either,
	// also tried setting allowCreationForSubProperty()
	// for childObjects AND childObjects.childObject

	$this->arguments['parentObject']
		->getPropertyMappingConfiguration()
->allowCreationForSubProperty('childObjects.childObject');
		
}


The form fields look like this:

// simple relation - works
tx_xxx_controllername[parentObject][childObject][title]

// Persistence_ObjectStorage - does not work
tx_xxx_controllername[parentObject][childObjects][0][title]


Any hint would be highly appreciated, I'm really stuck here.

Thanks in advance,
Best regards
Alex