[Form] Fixed: Empty forms can be compound too

src/Symfony/Component/Form/Extension/Core/DataMapper/PropertyPathMapper.php

@@ -24,7 +24,7 @@ class PropertyPathMapper implements DataMapperInterface
     public function mapDataToForms($data, array $forms)
     {
         if (!empty($data) && !is_array($data) && !is_object($data)) {
-            throw new UnexpectedTypeException($data, 'Object, array or empty');
+            throw new UnexpectedTypeException($data, 'object, array or empty');
         }
 
         if (!empty($data)) {

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

@@ -42,6 +42,7 @@ class FormType extends AbstractType
             ->setMapped($options['mapped'])
             ->setByReference($options['by_reference'])
             ->setVirtual($options['virtual'])
+            ->setCompound($options['compound'])
             ->setData($options['data'])
             ->setDataMapper(new PropertyPathMapper())
         ;
@@ -116,7 +117,7 @@ class FormType extends AbstractType
             'multipart'          => false,
             'attr'               => $options['attr'],
             'label_attr'         => $options['label_attr'],
-            'compound'           => $options['compound'],
+            'compound'           => $form->getConfig()->getCompound(),
             'types'              => $types,
             'translation_domain' => $translationDomain,
         ));
@@ -160,7 +161,7 @@ class FormType extends AbstractType
             }
 
             return function (FormInterface $form) {
-                return count($form) > 0 ? array() : '';
+                return $form->getConfig()->getCompound() ? array() : '';
             };
         };
 

src/Symfony/Component/Form/Form.php

@@ -345,7 +345,7 @@ class Form implements \IteratorAggregate, FormInterface
         $viewData = $this->normToView($normData);
 
         // Validate if view data matches data class (unless empty)
-        if (!empty($viewData)) {
+        if ('' !== $viewData && null !== $viewData) {
             $dataClass = $this->config->getDataClass();
 
             $actualType = is_object($viewData) ? 'an instance of class ' . get_class($viewData) : ' a(n) ' . gettype($viewData);
@@ -378,7 +378,7 @@ class Form implements \IteratorAggregate, FormInterface
         $this->viewData = $viewData;
         $this->synchronized = true;
 
-        if (count($this->children) > 0 && $this->config->getDataMapper()) {
+        if ($this->config->getCompound() && $this->config->getDataMapper()) {
             // Update child forms from the data
             $this->config->getDataMapper()->mapDataToForms($viewData, $this->children);
         }
@@ -477,37 +477,42 @@ class Form implements \IteratorAggregate, FormInterface
         $this->config->getEventDispatcher()->dispatch(FormEvents::BIND_CLIENT_DATA, $event);
         $submittedData = $event->getData();
 
-        // Build the data in the view format
+        // Check whether the form is compound.
-        $viewData = $submittedData;
+        // This check is preferrable over checking the number of children,
-
+        // since forms without children may also be compound.
-        if (count($this->children) > 0) {
+        // (think of empty collection forms)
-            if (null === $viewData || '' === $viewData) {
+        if ($this->config->getCompound()) {
-                $viewData = array();
+            if (null === $submittedData || '' === $submittedData) {
+                $submittedData = array();
             }
 
-            if (!is_array($viewData)) {
+            if (!is_array($submittedData)) {
-                throw new UnexpectedTypeException($viewData, 'array');
+                throw new UnexpectedTypeException($submittedData, 'array');
             }
 
             foreach ($this->children as $name => $child) {
-                if (!isset($viewData[$name])) {
+                if (!isset($submittedData[$name])) {
-                    $viewData[$name] = null;
+                    $submittedData[$name] = null;
                 }
             }
 
-            foreach ($viewData as $name => $value) {
+            foreach ($submittedData as $name => $value) {
                 if ($this->has($name)) {
                     $this->children[$name]->bind($value);
                 } else {
                     $extraData[$name] = $value;
                 }
             }
+        }
 
-            // If we have a data mapper, use old view data and merge
+        // By default, the submitted data is also the data in view format
-            // data from the children into it later
+        $viewData = $submittedData;
-            if ($this->config->getDataMapper()) {
+
-                $viewData = $this->getViewData();
+        // If the form is compound, the default data in view format
-            }
+        // is reused. The data of the children is merged into this
+        // default data using the data mapper.
+        if ($this->config->getCompound() && $this->config->getDataMapper()) {
+            $viewData = $this->getViewData();
         }
 
         if (null === $viewData || '' === $viewData) {
@@ -522,7 +527,7 @@ class Form implements \IteratorAggregate, FormInterface
         }
 
         // Merge form data from children into existing view data
-        if (count($this->children) > 0 && $this->config->getDataMapper() && null !== $viewData) {
+        if ($this->config->getCompound() && $this->config->getDataMapper() && null !== $viewData) {
             $this->config->getDataMapper()->mapFormsToData($this->children, $viewData);
         }
 
@@ -542,7 +547,6 @@ class Form implements \IteratorAggregate, FormInterface
             $this->config->getEventDispatcher()->dispatch(FormEvents::BIND_NORM_DATA, $event);
             $normData = $event->getData();
 
-
             // Synchronize representations - must not change the content!
             $modelData = $this->normToModel($normData);
             $viewData = $this->normToView($normData);
@@ -591,7 +595,7 @@ class Form implements \IteratorAggregate, FormInterface
                     // Form bound without name
                     $params = $request->request->all();
                     $files = $request->files->all();
-                } elseif (count($this->children) > 0) {
+                } elseif ($this->config->getCompound()) {
                     // Form bound with name and children
                     $params = $request->request->get($name, array());
                     $files = $request->files->get($name, array());
@@ -841,6 +845,10 @@ class Form implements \IteratorAggregate, FormInterface
             throw new AlreadyBoundException('You cannot add children to a bound form');
         }
 
+        if (!$this->config->getCompound()) {
+            throw new FormException('You cannot add children to a simple form. Maybe you should set the option "compound" to true?');
+        }
+
         $this->children[$child->getName()] = $child;
 
         $child->setParent($this);

src/Symfony/Component/Form/FormConfig.php

@@ -53,6 +53,11 @@ class FormConfig implements FormConfigEditorInterface
      */
     private $virtual = false;
 
+    /**
+     * @var Boolean
+     */
+    private $compound = true;
+
     /**
      * @var array
      */
@@ -356,6 +361,14 @@ class FormConfig implements FormConfigEditorInterface
         return $this->virtual;
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function getCompound()
+    {
+        return $this->compound;
+    }
+
     /**
      * {@inheritdoc}
      */
@@ -632,6 +645,16 @@ class FormConfig implements FormConfigEditorInterface
         return $this;
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function setCompound($compound)
+    {
+        $this->compound = $compound;
+
+        return $this;
+    }
+
     /**
      * {@inheritdoc}
      */

src/Symfony/Component/Form/FormConfigEditorInterface.php

@@ -199,6 +199,17 @@ interface FormConfigEditorInterface extends FormConfigInterface
      */
     function setVirtual($virtual);
 
+    /**
+     * Sets whether the form should be compound.
+     *
+     * @param  Boolean $compound Whether the form should be compound.
+     *
+     * @return self The configuration object.
+     *
+     * @see FormConfigInterface::getCompound()
+     */
+    function setCompound($compound);
+
     /**
      * Set the types.
      *

src/Symfony/Component/Form/FormConfigInterface.php

@@ -65,6 +65,17 @@ interface FormConfigInterface
      */
     function getVirtual();
 
+    /**
+     * Returns whether the form is compound.
+     *
+     * This property is independent of whether the form actually has
+     * children. A form can be compound and have no children at all, like
+     * for example an empty collection form.
+     *
+     * @return Boolean Whether the form is compound.
+     */
+    function getCompound();
+
     /**
      * Returns the form types used to construct the form.
      *

src/Symfony/Component/Form/Tests/Extension/Core/Type/CollectionTypeTest.php

@@ -18,7 +18,7 @@ class CollectionTypeTest extends TypeTestCase
     public function testContainsNoChildByDefault()
     {
         $form = $this->factory->create('collection', null, array(
-            'type' => 'form',
+            'type' => 'text',
         ));
 
         $this->assertCount(0, $form);
@@ -27,7 +27,7 @@ class CollectionTypeTest extends TypeTestCase
     public function testSetDataAdjustsSize()
     {
         $form = $this->factory->create('collection', null, array(
-            'type' => 'form',
+            'type' => 'text',
             'options' => array(
                 'max_length' => 20,
             ),
@@ -53,7 +53,7 @@ class CollectionTypeTest extends TypeTestCase
     public function testThrowsExceptionIfObjectIsNotTraversable()
     {
         $form = $this->factory->create('collection', null, array(
-            'type' => 'form',
+            'type' => 'text',
         ));
         $this->setExpectedException('Symfony\Component\Form\Exception\UnexpectedTypeException');
         $form->setData(new \stdClass());
@@ -62,7 +62,7 @@ class CollectionTypeTest extends TypeTestCase
     public function testNotResizedIfBoundWithMissingData()
     {
         $form = $this->factory->create('collection', null, array(
-            'type' => 'form',
+            'type' => 'text',
         ));
         $form->setData(array('foo@foo.com', 'bar@bar.com'));
         $form->bind(array('foo@bar.com'));
@@ -70,13 +70,13 @@ class CollectionTypeTest extends TypeTestCase
         $this->assertTrue($form->has('0'));
         $this->assertTrue($form->has('1'));
         $this->assertEquals('foo@bar.com', $form[0]->getData());
-        $this->assertNull($form[1]->getData());
+        $this->assertEquals('', $form[1]->getData());
     }
 
     public function testResizedDownIfBoundWithMissingDataAndAllowDelete()
     {
         $form = $this->factory->create('collection', null, array(
-            'type' => 'form',
+            'type' => 'text',
             'allow_delete' => true,
         ));
         $form->setData(array('foo@foo.com', 'bar@bar.com'));
@@ -91,7 +91,7 @@ class CollectionTypeTest extends TypeTestCase
     public function testNotResizedIfBoundWithExtraData()
     {
         $form = $this->factory->create('collection', null, array(
-            'type' => 'form',
+            'type' => 'text',
         ));
         $form->setData(array('foo@bar.com'));
         $form->bind(array('foo@foo.com', 'bar@bar.com'));
@@ -104,7 +104,7 @@ class CollectionTypeTest extends TypeTestCase
     public function testResizedUpIfBoundWithExtraDataAndAllowAdd()
     {
         $form = $this->factory->create('collection', null, array(
-            'type' => 'form',
+            'type' => 'text',
             'allow_add' => true,
         ));
         $form->setData(array('foo@bar.com'));

src/Symfony/Component/Form/Tests/Extension/Core/Type/FormTypeTest.php

@@ -77,6 +77,7 @@ class FormTypeTest extends TypeTestCase
                 null => '',
                 'reverse[a]' => 'a',
             )))
+            ->setCompound(false)
             ->getForm();
 
         $form->bind(' a ');
@@ -92,6 +93,7 @@ class FormTypeTest extends TypeTestCase
                 null => '',
                 'reverse[ a ]' => ' a ',
             )))
+            ->setCompound(false)
             ->getForm();
 
         $form->bind(' a ');
@@ -235,8 +237,8 @@ class FormTypeTest extends TypeTestCase
             'data_class' => 'Symfony\Component\Form\Tests\Fixtures\Author',
             'required' => false,
         ));
-        $form->add($this->factory->createNamed('firstName', 'form'));
+        $form->add($this->factory->createNamed('firstName', 'text'));
-        $form->add($this->factory->createNamed('lastName', 'form'));
+        $form->add($this->factory->createNamed('lastName', 'text'));
 
         $form->setData(null);
         // partially empty, still an object is created
@@ -256,8 +258,8 @@ class FormTypeTest extends TypeTestCase
             'data' => new Author(),
             'required' => false,
         ));
-        $form->add($this->factory->createNamed('firstName', 'form'));
+        $form->add($this->factory->createNamed('firstName', 'text'));
-        $form->add($this->factory->createNamed('lastName', 'form'));
+        $form->add($this->factory->createNamed('lastName', 'text'));
 
         $form->setData(null);
         // partially empty, still an object is created
@@ -276,7 +278,7 @@ class FormTypeTest extends TypeTestCase
             'data_class' => null,
             'required' => false,
         ));
-        $form->add($this->factory->createNamed('firstName', 'form'));
+        $form->add($this->factory->createNamed('firstName', 'text'));
 
         $form->setData(null);
         $form->bind(array('firstName' => 'Bernhard'));
@@ -290,8 +292,8 @@ class FormTypeTest extends TypeTestCase
             'data_class' => 'Symfony\Component\Form\Tests\Fixtures\Author',
             'required' => false,
         ));
-        $form->add($this->factory->createNamed('firstName', 'form'));
+        $form->add($this->factory->createNamed('firstName', 'text'));
-        $form->add($this->factory->createNamed('lastName', 'form'));
+        $form->add($this->factory->createNamed('lastName', 'text'));
 
         $form->setData(null);
         $form->bind(array('firstName' => '', 'lastName' => ''));
@@ -305,8 +307,8 @@ class FormTypeTest extends TypeTestCase
             'data_class' => 'Symfony\Component\Form\Tests\Fixtures\Author',
             'required' => true,
         ));
-        $form->add($this->factory->createNamed('firstName', 'form'));
+        $form->add($this->factory->createNamed('firstName', 'text'));
-        $form->add($this->factory->createNamed('lastName', 'form'));
+        $form->add($this->factory->createNamed('lastName', 'text'));
 
         $form->setData(null);
         $form->bind(array('firstName' => '', 'lastName' => ''));
@@ -320,7 +322,7 @@ class FormTypeTest extends TypeTestCase
     public function testBindWithEmptyDataStoresArrayIfNoClassAvailable()
     {
         $form = $this->factory->create('form');
-        $form->add($this->factory->createNamed('firstName', 'form'));
+        $form->add($this->factory->createNamed('firstName', 'text'));
 
         $form->setData(null);
         $form->bind(array('firstName' => 'Bernhard'));
@@ -328,7 +330,7 @@ class FormTypeTest extends TypeTestCase
         $this->assertSame(array('firstName' => 'Bernhard'), $form->getData());
     }
 
-    public function testBindWithEmptyDataPassesEmptyStringToTransformerIfNoChildren()
+    public function testBindWithEmptyDataPassesEmptyStringToTransformerIfNotCompound()
     {
         $form = $this->factory->createBuilder('form')
             ->addViewTransformer(new FixedDataTransformer(array(
@@ -337,6 +339,7 @@ class FormTypeTest extends TypeTestCase
                 // required to test that bind(null) is converted to ''
                 'empty' => '',
             )))
+            ->setCompound(false)
             ->getForm();
 
         $form->bind(null);
@@ -352,7 +355,7 @@ class FormTypeTest extends TypeTestCase
             'data_class' => 'Symfony\Component\Form\Tests\Fixtures\Author',
             'empty_data' => $author,
         ));
-        $form->add($this->factory->createNamed('firstName', 'form'));
+        $form->add($this->factory->createNamed('firstName', 'text'));
 
         $form->bind(array('firstName' => 'Bernhard'));
 
@@ -360,34 +363,31 @@ class FormTypeTest extends TypeTestCase
         $this->assertEquals('Bernhard', $author->firstName);
     }
 
+    public function provideZeros()
+    {
+        return array(
+            array(0, '0'),
+            array('0', '0'),
+            array('00000', '00000'),
+        );
+    }
+
     /**
+     * @dataProvider provideZeros
      * @see https://github.com/symfony/symfony/issues/1986
      */
-    public function testSetDataThroughParamsWithZero()
+    public function testSetDataThroughParamsWithZero($data, $dataAsString)
     {
-        $form = $this->factory->create('form', null, array('data' => 0));
+        $form = $this->factory->create('form', null, array(
+            'data' => $data,
+            'compound' => false,
+        ));
         $view = $form->createView();
 
         $this->assertFalse($form->isEmpty());
 
-        $this->assertSame('0', $view->getVar('value'));
+        $this->assertSame($dataAsString, $view->getVar('value'));
-        $this->assertSame('0', $form->getData());
+        $this->assertSame($dataAsString, $form->getData());
-
-        $form = $this->factory->create('form', null, array('data' => '0'));
-        $view = $form->createView();
-
-        $this->assertFalse($form->isEmpty());
-
-        $this->assertSame('0', $view->getVar('value'));
-        $this->assertSame('0', $form->getData());
-
-        $form = $this->factory->create('form', null, array('data' => '00000'));
-        $view = $form->createView();
-
-        $this->assertFalse($form->isEmpty());
-
-        $this->assertSame('00000', $view->getVar('value'));
-        $this->assertSame('00000', $form->getData());
     }
 
     /**
@@ -412,14 +412,14 @@ class FormTypeTest extends TypeTestCase
         $builder->add('reference', 'form', array(
             'data_class' => 'Symfony\Component\Form\Tests\Fixtures\Author',
         ));
-        $builder->get('reference')->add('firstName', 'form');
+        $builder->get('reference')->add('firstName', 'text');
         $form = $builder->getForm();
 
         $form->bind(array(
-        // reference has a getter, but not setter
+            // reference has a getter, but not setter
             'reference' => array(
                 'firstName' => 'Foo',
-        )
+            )
         ));
 
         $this->assertEquals('Foo', $author->getReference()->firstName);
@@ -435,7 +435,7 @@ class FormTypeTest extends TypeTestCase
         $builder->add('referenceCopy', 'form', array(
             'data_class' => 'Symfony\Component\Form\Tests\Fixtures\Author',
         ));
-        $builder->get('referenceCopy')->add('firstName', 'form');
+        $builder->get('referenceCopy')->add('firstName', 'text');
         $form = $builder->getForm();
 
         $form['referenceCopy']->setData($newReference); // new author object
@@ -459,7 +459,7 @@ class FormTypeTest extends TypeTestCase
             'data_class' => 'Symfony\Component\Form\Tests\Fixtures\Author',
             'by_reference' => false
         ));
-        $builder->get('referenceCopy')->add('firstName', 'form');
+        $builder->get('referenceCopy')->add('firstName', 'text');
         $form = $builder->getForm();
 
         $form->bind(array(

src/Symfony/Component/Form/Tests/Extension/Core/Type/RepeatedTypeTest.php

@@ -21,7 +21,7 @@ class RepeatedTypeTest extends TypeTestCase
         parent::setUp();
 
         $this->form = $this->factory->create('repeated', null, array(
-            'type' => 'form',
+            'type' => 'text',
         ));
         $this->form->setData(null);
     }
@@ -37,7 +37,7 @@ class RepeatedTypeTest extends TypeTestCase
     public function testSetOptions()
     {
         $form = $this->factory->create('repeated', null, array(
-            'type'    => 'form',
+            'type'    => 'text',
             'options' => array('label' => 'Global'),
         ));
 
@@ -51,7 +51,7 @@ class RepeatedTypeTest extends TypeTestCase
     {
         $form = $this->factory->create('repeated', null, array(
             // the global required value cannot be overriden
-            'type'           => 'form',
+            'type'           => 'text',
             'first_options'  => array('label' => 'Test', 'required' => false),
             'second_options' => array('label' => 'Test2')
         ));
@@ -66,7 +66,7 @@ class RepeatedTypeTest extends TypeTestCase
     {
         $form = $this->factory->create('repeated', null, array(
             'required' => false,
-            'type'     => 'form',
+            'type'     => 'text',
         ));
 
         $this->assertFalse($form['first']->isRequired());
@@ -76,7 +76,7 @@ class RepeatedTypeTest extends TypeTestCase
     public function testSetOptionsPerChildAndOverwrite()
     {
         $form = $this->factory->create('repeated', null, array(
-            'type'           => 'form',
+            'type'           => 'text',
             'options'        => array('label' => 'Label'),
             'second_options' => array('label' => 'Second label')
         ));

src/Symfony/Component/Form/Tests/Extension/Csrf/Type/FormTypeCsrfExtensionTest.php

@@ -148,12 +148,14 @@ class FormTypeCsrfExtensionTest extends TypeTestCase
             ->will($this->returnValue($valid));
 
         $form = $this->factory
-            ->create('form', null, array(
+            ->createBuilder('form', null, array(
                 'csrf_field_name' => 'csrf',
                 'csrf_provider' => $this->csrfProvider,
                 'intention' => '%INTENTION%',
                 'compound' => true,
-            ));
+            ))
+            ->add('child', 'text')
+            ->getForm();
 
         $form->bind(array(
             'child' => 'foobar',
@@ -173,12 +175,14 @@ class FormTypeCsrfExtensionTest extends TypeTestCase
             ->method('isCsrfTokenValid');
 
         $form = $this->factory
-            ->create('form', null, array(
+            ->createBuilder('form', null, array(
                 'csrf_field_name' => 'csrf',
                 'csrf_provider' => $this->csrfProvider,
                 'intention' => '%INTENTION%',
                 'compound' => true,
-            ));
+            ))
+            ->add('child', 'text')
+            ->getForm();
 
         $form->bind(array(
             'child' => 'foobar',

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

@@ -31,8 +31,6 @@ class FormTest extends \PHPUnit_Framework_TestCase
 
     private $factory;
 
-    private $builder;
-
     private $form;
 
     protected function setUp()
@@ -279,14 +277,15 @@ class FormTest extends \PHPUnit_Framework_TestCase
 
     public function testValidIfBound()
     {
-        $this->form->bind('foobar');
+        $form = $this->getBuilder()->setCompound(false)->getForm();
+        $form->bind('foobar');
 
-        $this->assertTrue($this->form->isValid());
+        $this->assertTrue($form->isValid());
     }
 
     public function testValidIfBoundAndDisabled()
     {
-        $form = $this->getBuilder()->setDisabled(true)->getForm();
+        $form = $this->getBuilder()->setCompound(false)->setDisabled(true)->getForm();
         $form->bind('foobar');
 
         $this->assertTrue($form->isValid());
@@ -318,10 +317,11 @@ class FormTest extends \PHPUnit_Framework_TestCase
 
     public function testNotValidIfErrors()
     {
-        $this->form->bind('foobar');
+        $form = $this->getBuilder()->setCompound(false)->getForm();
-        $this->form->addError(new FormError('Error!'));
+        $form->bind('foobar');
+        $form->addError(new FormError('Error!'));
 
-        $this->assertFalse($this->form->isValid());
+        $this->assertFalse($form->isValid());
     }
 
     public function testNotValidIfChildNotValid()
@@ -403,7 +403,7 @@ class FormTest extends \PHPUnit_Framework_TestCase
      */
     public function testRemoveThrowsExceptionIfAlreadyBound()
     {
-        $this->form->add($this->getBuilder('foo')->getForm());
+        $this->form->add($this->getBuilder('foo')->setCompound(false)->getForm());
         $this->form->bind(array('foo' => 'bar'));
         $this->form->remove('foo');
     }
@@ -445,9 +445,10 @@ class FormTest extends \PHPUnit_Framework_TestCase
 
     public function testBound()
     {
-        $this->form->bind('foobar');
+        $form = $this->getBuilder()->setCompound(false)->getForm();
+        $form->bind('foobar');
 
-        $this->assertTrue($this->form->isBound());
+        $this->assertTrue($form->isBound());
     }
 
     public function testNotBound()
@@ -586,7 +587,7 @@ class FormTest extends \PHPUnit_Framework_TestCase
      */
     public function testSetDataConvertsNullToStringIfNoTransformer()
     {
-        $form = $this->getBuilder()->getForm();
+        $form = $this->getBuilder()->setCompound(false)->getForm();
 
         $form->setData(null);
 
@@ -597,7 +598,7 @@ class FormTest extends \PHPUnit_Framework_TestCase
 
     public function testBindConvertsEmptyToNullIfNoTransformer()
     {
-        $form = $this->getBuilder()->getForm();
+        $form = $this->getBuilder()->setCompound(false)->getForm();
 
         $form->bind('');
 
@@ -641,6 +642,7 @@ class FormTest extends \PHPUnit_Framework_TestCase
     public function testBindExecutesViewTransformersInReverseOrder()
     {
         $form = $this->getBuilder()
+            ->setCompound(false)
             ->addViewTransformer(new FixedDataTransformer(array(
                 '' => '',
                 'third' => 'second',
@@ -659,6 +661,7 @@ class FormTest extends \PHPUnit_Framework_TestCase
     public function testBindExecutesModelTransformersInOrder()
     {
         $form = $this->getBuilder()
+            ->setCompound(false)
             ->addModelTransformer(new FixedDataTransformer(array(
                 '' => '',
                 'second' => 'first',
@@ -681,9 +684,10 @@ class FormTest extends \PHPUnit_Framework_TestCase
 
     public function testSynchronizedAfterBinding()
     {
-        $this->form->bind('foobar');
+        $form = $this->getBuilder()->setCompound(false)->getForm();
+        $form->bind('foobar');
 
-        $this->assertTrue($this->form->isSynchronized());
+        $this->assertTrue($form->isSynchronized());
     }
 
     public function testNotSynchronizedIfTransformationFailed()
@@ -694,6 +698,7 @@ class FormTest extends \PHPUnit_Framework_TestCase
             ->will($this->throwException(new TransformationFailedException()));
 
         $form = $this->getBuilder()
+            ->setCompound(false)
             ->addViewTransformer($transformer)
             ->getForm();
 
@@ -705,6 +710,7 @@ class FormTest extends \PHPUnit_Framework_TestCase
     public function testEmptyDataCreatedBeforeTransforming()
     {
         $form = $this->getBuilder()
+            ->setCompound(false)
             ->setEmptyData('foo')
             ->addViewTransformer(new FixedDataTransformer(array(
                 '' => '',
@@ -722,6 +728,7 @@ class FormTest extends \PHPUnit_Framework_TestCase
     {
         $test = $this;
         $form = $this->getBuilder()
+            ->setCompound(false)
             ->setEmptyData(function ($form) use ($test) {
                 // the form instance is passed to the closure to allow use
                 // of form data when creating the empty value
@@ -795,8 +802,8 @@ class FormTest extends \PHPUnit_Framework_TestCase
             ->setData('foo')
             ->getForm();
 
-        $form->add($child1 = $this->getBuilder('firstName')->getForm());
+        $form->add($child1 = $this->getBuilder('firstName')->setCompound(false)->getForm());
-        $form->add($child2 = $this->getBuilder('lastName')->getForm());
+        $form->add($child2 = $this->getBuilder('lastName')->setCompound(false)->getForm());
 
         $mapper->expects($this->once())
             ->method('mapFormsToData')
@@ -812,9 +819,25 @@ class FormTest extends \PHPUnit_Framework_TestCase
         ));
     }
 
+    /*
+     * https://github.com/symfony/symfony/issues/4480
+     */
+    public function testBindRestoresViewDataIfCompoundAndEmpty()
+    {
+        $mapper = $this->getDataMapper();
+        $object = new \stdClass();
+        $form = $this->getBuilder('name', null, 'stdClass')
+            ->setDataMapper($mapper)
+            ->setData($object)
+            ->getForm();
+
+        $form->bind(array());
+
+        $this->assertSame($object, $form->getData());
+    }
+
     public function testBindMapsBoundChildrenOntoEmptyData()
     {
-        $test = $this;
         $mapper = $this->getDataMapper();
         $object = new \stdClass();
         $form = $this->getBuilder()
@@ -823,7 +846,7 @@ class FormTest extends \PHPUnit_Framework_TestCase
             ->setData(null)
             ->getForm();
 
-        $form->add($child = $this->getBuilder('name')->getForm());
+        $form->add($child = $this->getBuilder('name')->setCompound(false)->getForm());
 
         $mapper->expects($this->once())
             ->method('mapFormsToData')
@@ -839,6 +862,7 @@ class FormTest extends \PHPUnit_Framework_TestCase
         $test = $this;
         $validator = $this->getFormValidator();
         $form = $this->getBuilder()
+            ->setCompound(false)
             ->addValidator($validator)
             ->getForm();
 
@@ -896,8 +920,8 @@ class FormTest extends \PHPUnit_Framework_TestCase
         ));
 
         $form = $this->getBuilder('author')->getForm();
-        $form->add($this->getBuilder('name')->getForm());
+        $form->add($this->getBuilder('name')->setCompound(false)->getForm());
-        $form->add($this->getBuilder('image')->getForm());
+        $form->add($this->getBuilder('image')->setCompound(false)->getForm());
 
         $form->bindRequest($request);
 
@@ -941,8 +965,8 @@ class FormTest extends \PHPUnit_Framework_TestCase
         ));
 
         $form = $this->getBuilder('')->getForm();
-        $form->add($this->getBuilder('name')->getForm());
+        $form->add($this->getBuilder('name')->setCompound(false)->getForm());
-        $form->add($this->getBuilder('image')->getForm());
+        $form->add($this->getBuilder('image')->setCompound(false)->getForm());
 
         $form->bindRequest($request);
 
@@ -981,7 +1005,7 @@ class FormTest extends \PHPUnit_Framework_TestCase
             'REQUEST_METHOD' => $method,
         ));
 
-        $form = $this->getBuilder('image')->getForm();
+        $form = $this->getBuilder('image')->setCompound(false)->getForm();
 
         $form->bindRequest($request);
 
@@ -1012,7 +1036,7 @@ class FormTest extends \PHPUnit_Framework_TestCase
             'REQUEST_METHOD' => $method,
         ));
 
-        $form = $this->getBuilder('name')->getForm();
+        $form = $this->getBuilder('name')->setCompound(false)->getForm();
 
         $form->bindRequest($request);
 
@@ -1039,8 +1063,8 @@ class FormTest extends \PHPUnit_Framework_TestCase
         ));
 
         $form = $this->getBuilder('author')->getForm();
-        $form->add($this->getBuilder('firstName')->getForm());
+        $form->add($this->getBuilder('firstName')->setCompound(false)->getForm());
-        $form->add($this->getBuilder('lastName')->getForm());
+        $form->add($this->getBuilder('lastName')->setCompound(false)->getForm());
 
         $form->bindRequest($request);
 
@@ -1065,8 +1089,8 @@ class FormTest extends \PHPUnit_Framework_TestCase
         ));
 
         $form = $this->getBuilder('')->getForm();
-        $form->add($this->getBuilder('firstName')->getForm());
+        $form->add($this->getBuilder('firstName')->setCompound(false)->getForm());
-        $form->add($this->getBuilder('lastName')->getForm());
+        $form->add($this->getBuilder('lastName')->setCompound(false)->getForm());
 
         $form->bindRequest($request);
 
@@ -1077,7 +1101,7 @@ class FormTest extends \PHPUnit_Framework_TestCase
 
     public function testBindResetsErrors()
     {
-        $form = $this->getBuilder()->getForm();
+        $form = $this->getBuilder()->setCompound(false)->getForm();
         $form->addError(new FormError('Error!'));
         $form->bind('foobar');
 

src/Symfony/Component/Form/UnmodifiableFormConfig.php

@@ -52,6 +52,11 @@ class UnmodifiableFormConfig implements FormConfigInterface
      */
     private $virtual;
 
+    /**
+     * @var Boolean
+     */
+    private $compound;
+
     /**
      * @var array
      */
@@ -135,6 +140,7 @@ class UnmodifiableFormConfig implements FormConfigInterface
         $this->mapped = $config->getMapped();
         $this->byReference = $config->getByReference();
         $this->virtual = $config->getVirtual();
+        $this->compound = $config->getCompound();
         $this->types = $config->getTypes();
         $this->clientTransformers = $config->getViewTransformers();
         $this->normTransformers = $config->getModelTransformers();
@@ -198,6 +204,14 @@ class UnmodifiableFormConfig implements FormConfigInterface
         return $this->virtual;
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function getCompound()
+    {
+        return $this->compound;
+    }
+
     /**
      * {@inheritdoc}
      */