feature symfony#5909 More 2.8 form updates (weaverryan)

This PR was merged into the 2.8 branch.

Discussion
----------

More 2.8 form updates

| Q             | A
|------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.8+
| Fixed tickets | symfony#5588

This is addition to what was done in symfony#5834. These changes are HUGE, so if anyone can review this for copy-paste changes or other mistakes, that would be awesome. Also, if you can think of any other things to search for the the code base and are able to find MORE instances, let me know.

Commits
-------

d131449 several other tweaks
feb68dd Completely updating the form type reference section for the text -> TextType changes
832a12a fixing build error
3117df5 Another huge batch of changes for the form type changes in 2.8

Author: weaverryan

Diff for: best_practices/forms.rst

@@ -110,6 +110,7 @@ some developers configure form buttons in the controller::
 
     use Symfony\Component\HttpFoundation\Request;
     use Symfony\Bundle\FrameworkBundle\Controller\Controller;
+    use Symfony\Component\Form\Extension\Core\Type\SubmitType;
     use AppBundle\Entity\Post;
     use AppBundle\Form\PostType;
 
@@ -121,7 +122,7 @@ some developers configure form buttons in the controller::
         {
             $post = new Post();
             $form = $this->createForm(PostType::class, $post);
-            $form->add('submit', 'submit', array(
+            $form->add('submit', SubmitType::class, array(
                 'label' => 'Create',
                 'attr'  => array('class' => 'btn btn-default pull-right')
             ));
@@ -205,21 +206,3 @@ Second, we recommend using ``$form->isSubmitted()`` in the ``if`` statement
 for clarity. This isn't technically needed, since ``isValid()`` first calls
 ``isSubmitted()``. But without this, the flow doesn't read well as it *looks*
 like the form is *always* processed (even on the GET request).
-
-Custom Form Field Types
------------------------
-
-.. best-practice::
-
-    Add the ``app_`` prefix to your custom form field types to avoid collisions.
-
-Custom form field types inherit from the ``AbstractType`` class, which defines the
-``getName()`` method to configure the name of that form type. These names must
-be unique in the application.
-
-If a custom form type uses the same name as any of the Symfony's built-in form
-types, it will override it. The same happens when the custom form type matches
-any of the types defined by the third-party bundles installed in your application.
-
-Add the ``app_`` prefix to your custom form field types to avoid name collisions
-that can lead to hard to debug errors.

Diff for: book/forms.rst

@@ -127,9 +127,10 @@ which HTML form tag(s) is rendered for that field.
 
 .. versionadded:: 2.8
     To denote the form type, you have to use the fully qualified class name - like
-    TextType::class in PHP 5.5+ or ``Symfony\Component\Form\Extension\Core\Type\TextType``.
+    ``TextType::class`` in PHP 5.5+ or ``Symfony\Component\Form\Extension\Core\Type\TextType``.
     Before Symfony 2.8, you could use an alias for each type like ``text`` or
-    ``date``. For more details, see the `2.8 UPGRADE Log`_.
+    ``date``. The old alias syntax will still work until Symfony 3.0. For more details,
+    see the `2.8 UPGRADE Log`_.
 
 Finally, you added a submit button with a custom label for submitting the form to
 the server.
@@ -1005,7 +1006,7 @@ ways. If you build your form in the controller, you can use ``setAction()`` and
         ->setAction($this->generateUrl('target_route'))
         ->setMethod('GET')
         ->add('task', TextType::class)
-        ->add('dueDate', DateType::clas)
+        ->add('dueDate', DateType::class)
         ->add('save', SubmitType::class)
         ->getForm();
 
@@ -1018,7 +1019,10 @@ In :ref:`book-form-creating-form-classes` you will learn how to move the
 form building code into separate classes. When using an external form class
 in the controller, you can pass the action and method as form options::
 
-    $form = $this->createForm(new TaskType(), $task, array(
+    use AppBundle\Form\Type\TaskType;
+    // ...
+
+    $form = $this->createForm(TaskType::class, $task, array(
         'action' => $this->generateUrl('target_route'),
         'method' => 'GET',
     ));

Diff for: book/validation.rst

@@ -230,7 +230,7 @@ workflow looks like the following from inside a controller::
     public function updateAction(Request $request)
     {
         $author = new Author();
-        $form = $this->createForm(new AuthorType(), $author);
+        $form = $this->createForm(AuthorType::class, $author);
 
         $form->handleRequest($request);
 

Diff for: cookbook/bundles/override.rst

@@ -105,17 +105,16 @@ associations. Learn more about this feature and its limitations in
 Forms
 -----
 
-In order to override a form type, it has to be registered as a service (meaning
-it is tagged as ``form.type``). You can then override it as you would override any
-service as explained in `Services & Configuration`_. This, of course, will only
-work if the type is referred to by its alias rather than being instantiated,
-e.g.::
+As of Symfony 2.8, form types are referred to by their fully-qualified class name::
 
-    $builder->add('name', 'custom_type');
+    $builder->add('name', CustomType::class);
 
-rather than::
+This means that you cannot override this by creating a sub-class of ``CustomType``
+and registering it as a service, and tagging it with ``form.type`` (you *could*
+do this in earlier version).
 
-    $builder->add('name', new CustomType());
+Instead, you should use a "form type extension" to modify the existing form type.
+For more information, see :doc:`/cookbook/form/create_form_type_extension`.
 
 .. _override-validation:
 

Diff for: cookbook/controller/upload_file.rst

@@ -57,14 +57,15 @@ Then, add a new ``brochure`` field to the form that manages the ``Product`` enti
     use Symfony\Component\Form\AbstractType;
     use Symfony\Component\Form\FormBuilderInterface;
     use Symfony\Component\OptionsResolver\OptionsResolver;
+    use Symfony\Component\Form\Extension\Core\Type\FileType;
 
     class ProductType extends AbstractType
     {
         public function buildForm(FormBuilderInterface $builder, array $options)
         {
             $builder
                 // ...
-                ->add('brochure', 'file', array('label' => 'Brochure (PDF file)'))
+                ->add('brochure', FileType::class, array('label' => 'Brochure (PDF file)'))
                 // ...
             ;
         }
@@ -116,7 +117,7 @@ Finally, you need to update the code of the controller that handles the form::
         public function newAction(Request $request)
         {
             $product = new Product();
-            $form = $this->createForm(new ProductType(), $product);
+            $form = $this->createForm(ProductType::class, $product);
             $form->handleRequest($request);
 
             if ($form->isValid()) {

Diff for: cookbook/form/create_custom_field_type.rst

@@ -25,6 +25,7 @@ for form fields, which is ``<BundleName>\Form\Type``. Make sure the field extend
 
     use Symfony\Component\Form\AbstractType;
     use Symfony\Component\OptionsResolver\OptionsResolver;
+    use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
 
     class GenderType extends AbstractType
     {
@@ -40,12 +41,7 @@ for form fields, which is ``<BundleName>\Form\Type``. Make sure the field extend
 
         public function getParent()
         {
-            return 'choice';
-        }
-
-        public function getName()
-        {
-            return 'gender';
+            return ChoiceType::class;
         }
     }
 
@@ -54,8 +50,12 @@ for form fields, which is ``<BundleName>\Form\Type``. Make sure the field extend
     The location of this file is not important - the ``Form\Type`` directory
     is just a convention.
 
+.. versionadded:: 2.8
+    In 2.8, the ``getName()`` method was removed. Now, fields are always referred
+    to by their fully-qualified class name.
+
 Here, the return value of the ``getParent`` function indicates that you're
-extending the ``choice`` field type. This means that, by default, you inherit
+extending the ``ChoiceType`` field. This means that, by default, you inherit
 all of the logic and rendering of that field type. To see some of the logic,
 check out the `ChoiceType`_ class. There are three methods that are particularly
 important:
@@ -89,24 +89,26 @@ important:
     Also, if you need to modify the "view" of any of your child types from
     your parent type, use the ``finishView()`` method.
 
-The ``getName()`` method returns an identifier which should be unique in
-your application. This is used in various places, such as when customizing
-how your form type will be rendered.
-
 The goal of this field was to extend the choice type to enable selection of
 a gender. This is achieved by fixing the ``choices`` to a list of possible
 genders.
 
 Creating a Template for the Field
 ---------------------------------
 
-Each field type is rendered by a template fragment, which is determined in
-part by the value of your ``getName()`` method. For more information, see
+Each field type is rendered by a template fragment, which is determined in part by
+the class name of your type. For more information, see
 :ref:`cookbook-form-customization-form-themes`.
 
-In this case, since the parent field is ``choice``, you don't *need* to do
-any work as the custom field type will automatically be rendered like a ``choice``
-type. But for the sake of this example, suppose that when your field is "expanded"
+.. note::
+
+    The first part of the prefix (e.g. ``gender``) comes from the class name
+    (``GenderType`` -> ``gender``). This can be controlled by overriding ``getBlockPrefix()``
+    in ``GenderType``.
+
+In this case, since the parent field is ``ChoiceType``, you don't *need* to do
+any work as the custom field type will automatically be rendered like a ``ChoiceType``.
+But for the sake of this example, suppose that when your field is "expanded"
 (i.e. radio buttons or checkboxes, instead of a select field), you want to
 always render it in a ``ul`` element. In your form theme template (see above
 link for details), create a ``gender_widget`` block to handle this:
@@ -154,7 +156,7 @@ link for details), create a ``gender_widget`` block to handle this:
 .. note::
 
     Make sure the correct widget prefix is used. In this example the name should
-    be ``gender_widget``, according to the value returned by ``getName``.
+    be ``gender_widget`` (see :ref:`cookbook-form-customization-form-themes`).
     Further, the main config file should point to the custom form template
     so that it's used when rendering all forms.
 
@@ -241,18 +243,19 @@ new instance of the type in one of your forms::
 
     use Symfony\Component\Form\AbstractType;
     use Symfony\Component\Form\FormBuilderInterface;
+    use AppBundle\Form\Type\GenderType;
 
     class AuthorType extends AbstractType
     {
         public function buildForm(FormBuilderInterface $builder, array $options)
         {
-            $builder->add('gender_code', new GenderType(), array(
+            $builder->add('gender_code', GenderType::class, array(
                 'placeholder' => 'Choose a gender',
             ));
         }
     }
 
-But this only works because the ``GenderType()`` is very simple. What if
+But this only works because the ``GenderType`` is very simple. What if
 the gender codes were stored in configuration or in a database? The next
 section explains how more complex field types solve this problem.
 
@@ -311,14 +314,14 @@ the ``genders`` parameter value as the first argument to its to-be-created
                 arguments:
                     - "%genders%"
                 tags:
-                    - { name: form.type, alias: gender }
+                    - { name: form.type }
 
     .. code-block:: xml
 
         <!-- src/AppBundle/Resources/config/services.xml -->
         <service id="app.form.type.gender" class="AppBundle\Form\Type\GenderType">
             <argument>%genders%</argument>
-            <tag name="form.type" alias="gender" />
+            <tag name="form.type" />
         </service>
 
     .. code-block:: php
@@ -331,20 +334,16 @@ the ``genders`` parameter value as the first argument to its to-be-created
                 'AppBundle\Form\Type\GenderType',
                 array('%genders%')
             ))
-            ->addTag('form.type', array(
-                'alias' => 'gender',
-            ))
+            ->addTag('form.type')
         ;
 
 .. tip::
 
     Make sure the services file is being imported. See :ref:`service-container-imports-directive`
     for details.
 
-Be sure that the ``alias`` attribute of the tag corresponds with the value
-returned by the ``getName`` method defined earlier. You'll see the importance
-of this in a moment when you use the custom field type. But first, add a ``__construct``
-method to ``GenderType``, which receives the gender configuration::
+First, add a ``__construct`` method to ``GenderType``, which receives the gender
+configuration::
 
     // src/AppBundle/Form/Type/GenderType.php
     namespace AppBundle\Form\Type;
@@ -374,28 +373,28 @@ method to ``GenderType``, which receives the gender configuration::
     }
 
 Great! The ``GenderType`` is now fueled by the configuration parameters and
-registered as a service. Additionally, because you used the ``form.type`` alias in its
-configuration, using the field is now much easier::
+registered as a service. Because you used the ``form.type`` alias in its configuration,
+your service will be used instead of creating a *new* ``GenderType``. In other words,
+your controller *does not need to change*, it still looks like this::
 
     // src/AppBundle/Form/Type/AuthorType.php
     namespace AppBundle\Form\Type;
 
+    use Symfony\Component\Form\AbstractType;
     use Symfony\Component\Form\FormBuilderInterface;
-
-    // ...
+    use AppBundle\Form\Type\GenderType;
 
     class AuthorType extends AbstractType
     {
         public function buildForm(FormBuilderInterface $builder, array $options)
         {
-            $builder->add('gender_code', 'gender', array(
+            $builder->add('gender_code', GenderType::class, array(
                 'placeholder' => 'Choose a gender',
             ));
         }
     }
 
-Notice that instead of instantiating a new instance, you can just refer to
-it by the alias used in your service configuration, ``gender``. Have fun!
+Have fun!
 
 .. _`ChoiceType`: https://github.com/symfony/symfony/blob/master/src/Symfony/Component/Form/Extension/Core/Type/ChoiceType.php
 .. _`FieldType`: https://github.com/symfony/symfony/blob/master/src/Symfony/Component/Form/Extension/Core/Type/FieldType.php