[Form] Fixed caching of block names when types of forms with the same unique block ID differ

src/Symfony/Component/Form/AbstractRendererEngine.php

@@ -21,7 +21,7 @@ abstract class AbstractRendererEngine implements FormRendererEngineInterface
     /**
      * The variable in {@link FormView} used as cache key.
      */
-    const CACHE_KEY_VAR = 'full_block_name';
+    const CACHE_KEY_VAR = 'cache_key';
     
     /**
      * @var array

src/Symfony/Component/Form/Extension/Core/Type/FormType.php

@@ -129,6 +129,13 @@ class FormType extends AbstractType
             'compound'           => $form->getConfig()->getCompound(),
             'types'              => $types,
             'translation_domain' => $translationDomain,
+            // Using the block name here speeds up performance in collection
+            // forms, where each entry has the same full block name.
+            // Including the type is important too, because if rows of a
+            // collection form have different types (dynamically), they should
+            // be rendered differently.
+            // https://github.com/symfony/symfony/issues/5038
+            'cache_key'          => $fullBlockName . '_' . $form->getConfig()->getType()->getName(),
         ));
     }
 

src/Symfony/Component/Form/Tests/AbstractDivLayoutTest.php

@@ -12,6 +12,7 @@
 namespace Symfony\Component\Form\Tests;
 
 use Symfony\Component\Form\FormError;
+use Symfony\Component\Form\Tests\Fixtures\AlternatingRowType;
 
 abstract class AbstractDivLayoutTest extends AbstractLayoutTest
 {
@@ -283,6 +284,29 @@ abstract class AbstractDivLayoutTest extends AbstractLayoutTest
         );
     }
 
+    // https://github.com/symfony/symfony/issues/5038
+    public function testCollectionWithAlternatingRowTypes()
+    {
+        $data = array(
+            array('title' => 'a'),
+            array('title' => 'b'),
+        );
+        $form = $this->factory->createNamed('name', 'collection', $data, array(
+            'type' => new AlternatingRowType(),
+        ));
+
+        $this->assertWidgetMatchesXpath($form->createView(), array(),
+'/div
+    [
+        ./div[./div/div/input[@type="text"][@value="a"]]
+        /following-sibling::div[./div/div/textarea[.="b"]]
+    ]
+    [count(./div[./div/div/input])=1]
+    [count(./div[./div/div/textarea])=1]
+'
+        );
+    }
+
     public function testEmptyCollection()
     {
         $form = $this->factory->createNamed('name', 'collection', array(), array(

src/Symfony/Component/Form/Tests/Fixtures/AlternatingRowType.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Symfony\Component\Form\Tests\Fixtures;
+
+use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\FormEvents;
+use Symfony\Component\Form\FormEvent;
+use Symfony\Component\Form\FormBuilderInterface;
+
+class AlternatingRowType extends AbstractType
+{
+    public function buildForm(FormBuilderInterface $builder, array $options)
+    {
+        $formFactory = $builder->getFormFactory();
+
+        $builder->addEventListener(FormEvents::PRE_SET_DATA, function (FormEvent $event) use ($formFactory) {
+            $form = $event->getForm();
+            $type = $form->getName() % 2 === 0 ? 'text' : 'textarea';
+            $form->add($formFactory->createNamed('title', $type));
+        });
+    }
+
+    public function getName()
+    {
+        return 'alternating_row';
+    }
+}