Nested CollectionTypes

[TheFox]

I have a similar problem to #6777. In the latest version 3.105.3 in AdminHelper, the line

$childFormBuilder = $this->getChildFormBuilder($formBuilder, $elementId);

in is returning null when I am using nested Sonata\Form\Type\CollectionType.

In my Entity I have to expose the Collection

public function getAnswers(): Collection
{
    return $this->answers;
}

instead of only the array

/**
 * @return array<Answer>
 */
public function getAnswers(): array
{
    return $this->answers->toArray();
}

Otherwise it will not work because the else block is reached in the AdminHelper class.

In the loop of getChildFormBuilder the value for $elementId is s616839720b0e2_questions_0_answers. But there is only a s616839720b0e2_questions in the array (iterator). Not sure if this is the case of the problem.

[VincentLanglet]

It seems the right way to me to always expose the Collection. Especially for something called a CollectionType.
Never used an array instead of Collection for my entities.

[TheFox]

@VincentLanglet Depends on who you ask. If you ask the SensioLabs guys the collection should not be exposed. In my opinion it shouldn't matter. But who am I, right?

It shouldn't matter if you want to use array or Collection or any other array-like object. If Sonata would use ArrayAccess it shouldn't matter at all.

Instead of calling

$collection->add(new $modelClassName());

you could easily change it to

$collection[] = new $modelClassName();

This would be compatible and easy to change. Doctrine\Common\Collections\Collection already extends from ArrayAccess. And the code would be compatible with other array like objects/interfaces.

You could even remove the check

if (!($collection instanceof Collection))

or just change it to

if (!($collection instanceof \ArrayAccess))

Edit: you have to remove

if (!($collection instanceof Collection))

Native array is not an instanceof \ArrayAccess.

[TheFox]

@jordisala1991 @VincentLanglet Thank you for the support for ArrayAccess.

I just wondered if all the locations in the code where Collection is used is now supposed to be supported by ArrayAccess, or only this one case in AdminHelper. For example here it is still only Collection, no ArrayAccess:

SonataAdminBundle/src/Form/EventListener/MergeCollectionListener.php

Line 36 in 1f22334

\assert(null === $collection || $collection instanceof Collection);