How to embed a precharged collection of non-entity forms in symfony2

Per the documentation on Using a Form Without a Class, the bound data is just an array.

If you don't do either of these, then the form will return the data as an array. In this example, since $defaultData is not an object (and no data_class option is set), $form->getData() ultimately returns an array.

And to clear up any misconception you might have about form data - the underlying object/class of a form type does not have to be an Entity - you can use any class with public properties or getters/setters that map to the form fields. For that matter, Entity classes are nothing special themselves - they just have a bunch of mapping information that tells the ORM how to persist them.

But, back to your original question, I don't know what your ChildFormType looks like, but let's assume it has two fields, sequence and title

    $form->add('aclAccess', 'collection', array(        'type' => new ChildFormType(),        'allow_add' => true,        'mapped' => false,        'data' => array(            array('sequence' => 1, 'title' => 'Foo')          , array('sequence' => 2, 'title' => 'Bar')        )    ));

That should do the trick