feature #15079 [Form] Deprecated FormTypeInterface::getName() and passing of type instances (webmozart)

This PR was merged into the 2.8 branch.

Discussion
----------

[Form] Deprecated FormTypeInterface::getName() and passing of type instances

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | yes
| Tests pass?   | yes
| Fixed tickets | #5321, #15008
| License       | MIT
| Doc PR        | TODO

#### Type Names

This PR deprecates the definition of the `getName()` method of form types. See #15008 for a more detailed description.

Before:

```php
class MyType extends AbstractType
{
    public function getName()
    {
        return 'mytype';
    }

    // ...
}
```

After:

```php
class MyType extends AbstractType
{
    // ...
}
```

You should always reference other types by their fully-qualified class names. Thanks to PHP 5.5, that's easy:

Before:

```php
$form = $this->createFormBuilder()
    ->add('name', 'text')
    ->add('age', 'integer')
    ->getForm();
```

After:

```php
$form = $this->createFormBuilder()
    ->add('name', TextType::class)
    ->add('age', IntegerType::class)
    ->getForm();
```

#### Type Instances

Furthermore, passing of type instances is deprecated.

Before:

```php
$form = $this->createForm(new AuthorType());
```

After:

```php
$form = $this->createForm(AuthorType::class);
```

#### DIC Aliases

When registering a type in the DIC, you should omit the "alias" attribute now.

Before:

```xml
<service id="my.type" class="Vendor\Type\MyType">
    <tag name="form.type" alias="mytype" />
    <argument type="service" id="some.service.id" />
</service>
```

After:

```xml
<service id="my.type" class="Vendor\Type\MyType">
    <tag name="form.type" />
    <argument type="service" id="some.service.id" />
</service>
```

Types without dependencies don't need to be registered in the DIC as they can be instantiated right away.

#### Template Block Prefixes

By default, the class name of the type in underscore notation minus "Type" suffix is used as Twig template block prefix (e.g. `UserProfileType` => `user_profile_*`). If you want to customize that, overwrite the new `getBlockPrefix()` method in your type:

```php
class UserProfileType extends AbstractType
{
    public function getBlockPrefix()
    {
        return 'profile';
    }

    // ...
}
```

Commits
-------

3d9e5de [Form] Deprecated FormTypeInterface::getName() and passing of type instances

Author: fabpot

Tests/Functional/Bundle/CsrfFormLoginBundle/Controller/LoginController.php

@@ -19,7 +19,7 @@ class LoginController extends ContainerAware
 {
     public function loginAction()
     {
-        $form = $this->container->get('form.factory')->create('user_login');
+        $form = $this->container->get('form.factory')->create('Symfony\Bundle\SecurityBundle\Tests\Functional\Bundle\CsrfFormLoginBundle\Form\UserLoginType');
 
         return $this->container->get('templating')->renderResponse('CsrfFormLoginBundle:Login:login.html.twig', array(
             'form' => $form->createView(),

Tests/Functional/Bundle/CsrfFormLoginBundle/Form/UserLoginFormType.php renamed to Tests/Functional/Bundle/CsrfFormLoginBundle/Form/UserLoginType.php

@@ -27,7 +27,7 @@
  * @author Henrik Bjornskov <[email protected]>
  * @author Jeremy Mikola <[email protected]>
  */
-class UserLoginFormType extends AbstractType
+class UserLoginType extends AbstractType
 {
     private $requestStack;
 
@@ -45,9 +45,9 @@ public function __construct(RequestStack $requestStack)
     public function buildForm(FormBuilderInterface $builder, array $options)
     {
         $builder
-            ->add('username', 'text')
-            ->add('password', 'password')
-            ->add('_target_path', 'hidden')
+            ->add('username', 'Symfony\Component\Form\Extension\Core\Type\TextType')
+            ->add('password', 'Symfony\Component\Form\Extension\Core\Type\PasswordType')
+            ->add('_target_path', 'Symfony\Component\Form\Extension\Core\Type\HiddenType')
         ;
 
         $request = $this->requestStack->getCurrentRequest();
@@ -87,12 +87,4 @@ public function configureOptions(OptionsResolver $resolver)
             'intention' => 'authenticate',
         ));
     }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function getName()
-    {
-        return 'user_login';
-    }
 }

Tests/Functional/app/CsrfFormLogin/config.yml

@@ -3,11 +3,11 @@ imports:
 
 services:
     csrf_form_login.form.type:
-        class: Symfony\Bundle\SecurityBundle\Tests\Functional\Bundle\CsrfFormLoginBundle\Form\UserLoginFormType
+        class: Symfony\Bundle\SecurityBundle\Tests\Functional\Bundle\CsrfFormLoginBundle\Form\UserLoginType
         arguments:
             - @request_stack
         tags:
-            - { name: form.type, alias: user_login }
+            - { name: form.type }
 
 security:
     encoders: