Could you also keep getName()? I think it's still needed for symfony 2.8.

Both are needed only for Symfony <2.8 compatibility.

2.8 and 3.0 are the same, except the deprecation removal.

ah yep, that's probably why I dropped symfony 2.7 support 😃

so, do I need to keep getName() function?

Nope, getName() only exists until symfony 2.7 and we only support >=2.8.

But actually I don't really see how this type can work in Symfony3 at the moment. As it has to be referenced by FQCN now how would you distinguish choice from hidden? @davidzzz did you manage to make it work or are you just looking into this?

I tried it in symfony 2.8. Here is my code
$builder->add('test', new Select2Type('entity'), array('label' => 'Test', 'class' => MyTestBundle:Test'));
Still get deprecation warning, but it works as expected.

I see, unfortunately this wouldn't work for Symfony 3.0, cf. the snipped below which is extracted from https://github.com/symfony/symfony/blob/master/UPGRADE-3.0.md :

Passing type instances to Form::add(), FormBuilder::add() and the FormFactory::create*() methods is not supported anymore. Pass the fully-qualified class name of the type instead.

Before:

$form = $this->createForm(new MyType());

After:

$form = $this->createForm(MyType::class);

So we can't use the current magic constructor to register different types from the same class anymore :/

An option could be to switch to something like this instead : http://symfony.com/doc/current/cookbook/form/create_form_type_extension.html

So, if I want to pass the object to the form, how can I do that?

As of 3.0 you can only pass the class, it the form type needs an object it can be registered as a service.

I'll merge your PR for now, removing some deprecations doesn't hurt. But please look for alternatives, I'll probably deprecate this whole feature as there seems to be no simple fix for Symfony 3. If you want to "selectify" a choice type, you can just add a css class to it and have some js around.