[Form] Ease immutable/value objects mapping

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

@@ -0,0 +1,41 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Form\Extension\Core\DataMapper;
+
+/**
+ * @author Maxime Steinhausser <maxime.steinhausser@gmail.com>
+ */
+class CallbackFormDataToObjectConverter implements FormDataToObjectConverterInterface
+{
+    /**
+     * The callable used to map form data to an object.
+     *
+     * @var callable
+     */
+    private $converter;
+
+    /**
+     * @param callable $converter
+     */
+    public function __construct(callable $converter)
+    {
+        $this->converter = $converter;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function convertFormDataToObject(array $data, $originalData)
+    {
+        return call_user_func($this->converter, $data, $originalData);
+    }
+}

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

@@ -0,0 +1,28 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Form\Extension\Core\DataMapper;
+
+/**
+ * @author Maxime Steinhausser <maxime.steinhausser@gmail.com>
+ */
+interface FormDataToObjectConverterInterface
+{
+    /**
+     * Convert the form data into an object.
+     *
+     * @param array       $data         Array of form data indexed by fields names.
+     * @param object|null $originalData Original data set in the form (after FormEvents::PRE_SET_DATA).
+     *
+     * @return object|null
+     */
+    public function convertFormDataToObject(array $data, $originalData);
+}

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

@@ -0,0 +1,27 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Form\Extension\Core\DataMapper;
+
+/**
+ * @author Maxime Steinhausser <maxime.steinhausser@gmail.com>
+ */
+interface ObjectToFormDataConverterInterface
+{
+    /**
+     * Convert given object to form data.
+     *
+     * @param object|null $object The object to map to the form.
+     *
+     * @return array The array of form data indexed by fields names.
+     */
+    public function convertObjectToFormData($object);
+}

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

@@ -0,0 +1,91 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Form\Extension\Core\DataMapper;
+
+use Symfony\Component\Form\DataMapperInterface;
+use Symfony\Component\Form\Exception\UnexpectedTypeException;
+
+/**
+ * @author Maxime Steinhausser <maxime.steinhausser@gmail.com>
+ */
+class SimpleObjectMapper implements DataMapperInterface
+{
+    /**
+     * @var FormDataToObjectConverterInterface
+     */
+    private $converter;
+
+    /**
+     * @var DataMapperInterface|null
+     */
+    private $originalMapper;
+
+    /**
+     * @param FormDataToObjectConverterInterface $converter
+     * @param DataMapperInterface|null           $originalMapper
+     */
+    public function __construct(FormDataToObjectConverterInterface $converter, DataMapperInterface $originalMapper = null)
+    {
+        $this->converter = $converter;
+        $this->originalMapper = $originalMapper;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function mapDataToForms($data, $forms)
+    {
+        // Fallback to original mapper instance or default to "PropertyPathMapper"
+        // mapper implementation if not an "ObjectToFormDataConverterInterface" instance:
+        if (!$this->converter instanceof ObjectToFormDataConverterInterface) {
+            $propertyPathMapper = $this->originalMapper ?: new PropertyPathMapper();
+            $propertyPathMapper->mapDataToForms($data, $forms);
+
+            return;
+        }
+
+        if (!is_object($data) && null !== $data) {
+            throw new UnexpectedTypeException($data, 'object or null');
+        }
+
+        $data = $this->converter->convertObjectToFormData($data);
+
+        if (!is_array($data)) {
+            throw new UnexpectedTypeException($data, 'array');
+        }
+
+        foreach ($forms as $form) {
+            $config = $form->getConfig();
+
+            if ($config->getMapped() && isset($data[$form->getName()])) {
+                $form->setData($data[$form->getName()]);
+
+                continue;
+            }
+
+            $form->setData($config->getData());
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function mapFormsToData($forms, &$data)
+    {
+        $fieldsData = array();
+        foreach ($forms as $form) {
+            $fieldsData[$form->getName()] = $form->getData();
+        }
+
+        $data = $this->converter->convertFormDataToObject($fieldsData, $data);
+    }
+}

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

@@ -11,6 +11,9 @@
 
 namespace Symfony\Component\Form\Extension\Core\Type;
 
+use Symfony\Component\Form\Extension\Core\DataMapper\CallbackFormDataToObjectConverter;
+use Symfony\Component\Form\Extension\Core\DataMapper\FormDataToObjectConverterInterface;
+use Symfony\Component\Form\Extension\Core\DataMapper\SimpleObjectMapper;
 use Symfony\Component\Form\FormBuilderInterface;
 use Symfony\Component\Form\FormInterface;
 use Symfony\Component\Form\FormView;
@@ -43,6 +46,15 @@ public function buildForm(FormBuilderInterface $builder, array $options)
 
         $isDataOptionSet = array_key_exists('data', $options);
 
+        $dataMapper = null;
+        if ($options['compound']) {
+            $dataMapper = new PropertyPathMapper($this->propertyAccessor);
+
+            if (isset($options['simple_object_mapper'])) {
+                $dataMapper = new SimpleObjectMapper($options['simple_object_mapper'], $dataMapper);
+            }
+        }
+
         $builder
             ->setRequired($options['required'])
             ->setErrorBubbling($options['error_bubbling'])
@@ -54,7 +66,7 @@ public function buildForm(FormBuilderInterface $builder, array $options)
             ->setCompound($options['compound'])
             ->setData($isDataOptionSet ? $options['data'] : null)
             ->setDataLocked($isDataOptionSet)
-            ->setDataMapper($options['compound'] ? new PropertyPathMapper($this->propertyAccessor) : null)
+            ->setDataMapper($dataMapper)
             ->setMethod($options['method'])
             ->setAction($options['action']);
 
@@ -133,6 +145,11 @@ public function configureOptions(OptionsResolver $resolver)
 
             if (null !== $class) {
                 return function (FormInterface $form) use ($class) {
+                    // If the "SimpleObjectMapper" is used, the "empty_data" option value should be null:
+                    if ($form->getConfig()->getDataMapper() instanceof SimpleObjectMapper) {
+                        return;
+                    }
+
                     return $form->isEmpty() && !$form->isRequired() ? null : new $class();
                 };
             }
@@ -155,6 +172,18 @@ public function configureOptions(OptionsResolver $resolver)
             return $options['compound'];
         };
 
+        $simpleObjectMapperNormalizer = function (Options $options, $value) {
+            if (null === $value) {
+                return;
+            }
+
+            if (!$value instanceof FormDataToObjectConverterInterface && is_callable($value)) {
+                return new CallbackFormDataToObjectConverter($value);
+            }
+
+            return $value;
+        };
+
         // If data is given, the form is locked to that data
         // (independent of its value)
         $resolver->setDefined(array(
@@ -180,10 +209,14 @@ public function configureOptions(OptionsResolver $resolver)
             'attr' => array(),
             'post_max_size_message' => 'The uploaded file was too large. Please try to upload a smaller file.',
             'upload_max_size_message' => $uploadMaxSizeMessage, // internal
+            'simple_object_mapper' => null,
         ));
 
+        $resolver->setNormalizer('simple_object_mapper', $simpleObjectMapperNormalizer);
+
         $resolver->setAllowedTypes('label_attr', 'array');
         $resolver->setAllowedTypes('upload_max_size_message', array('callable'));
+        $resolver->setAllowedTypes('simple_object_mapper', array(FormDataToObjectConverterInterface::class, 'null', 'callable'));
     }
 
     /**

src/Symfony/Component/Form/Tests/Extension/Core/DataMapper/CallbackFormDataToObjectConverterTest.php

@@ -0,0 +1,32 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Form\Tests\Extension\Core\DataMapper;
+
+use Symfony\Component\Form\Extension\Core\DataMapper\CallbackFormDataToObjectConverter;
+
+class CallbackFormDataToObjectConverterTest extends \PHPUnit_Framework_TestCase
+{
+    public function testConvertFormDataToObject()
+    {
+        $data = array('amount' => 15.0, 'currency' => 'EUR');
+        $originalData = (object) $data;
+
+        $converter = new CallbackFormDataToObjectConverter(function ($arg1, $arg2) use ($data, $originalData) {
+            $this->assertSame($data, $arg1);
+            $this->assertSame($originalData, $arg2);
+
+            return 'converted';
+        });
+
+        $this->assertSame('converted', $converter->convertFormDataToObject($data, $originalData));
+    }
+}