[Serializer] Add Support of recursive denormalization on object_to_populate

src/Symfony/Component/Serializer/CHANGELOG.md

@@ -6,6 +6,7 @@ CHANGELOG
 
  * added the list of constraint violations' parameters in `ConstraintViolationListNormalizer`
  * added support for serializing `DateTimeZone` objects
+ * added a `deep_object_to_populate` context option to recursive denormalize on `object_to_populate` object.
 
 4.2.0
 -----

src/Symfony/Component/Serializer/Normalizer/AbstractObjectNormalizer.php

@@ -12,6 +12,7 @@
 namespace Symfony\Component\Serializer\Normalizer;
 
 use Symfony\Component\PropertyAccess\Exception\InvalidArgumentException;
+use Symfony\Component\PropertyAccess\Exception\NoSuchPropertyException;
 use Symfony\Component\PropertyInfo\PropertyTypeExtractorInterface;
 use Symfony\Component\PropertyInfo\Type;
 use Symfony\Component\Serializer\Encoder\JsonEncoder;
@@ -38,6 +39,7 @@ abstract class AbstractObjectNormalizer extends AbstractNormalizer
     const SKIP_NULL_VALUES = 'skip_null_values';
     const MAX_DEPTH_HANDLER = 'max_depth_handler';
     const EXCLUDE_FROM_CACHE_KEY = 'exclude_from_cache_key';
+    const DEEP_OBJECT_TO_POPULATE = 'deep_object_to_populate';
 
     private $propertyTypeExtractor;
     private $typesCache = [];
@@ -274,6 +276,13 @@ abstract class AbstractObjectNormalizer extends AbstractNormalizer
                 continue;
             }
 
+            if ($context[self::DEEP_OBJECT_TO_POPULATE] ?? $this->defaultContext[self::DEEP_OBJECT_TO_POPULATE] ?? false) {
+                try {
+                    $context[self::OBJECT_TO_POPULATE] = $this->getAttributeValue($object, $attribute, $format, $context);
+                } catch (NoSuchPropertyException $e) {
+                }
+            }
+
             $value = $this->validateAndDenormalize($class, $attribute, $value, $format, $context);
             try {
                 $this->setAttributeValue($object, $attribute, $value, $format, $context);

src/Symfony/Component/Serializer/Normalizer/ObjectToPopulateTrait.php

@@ -26,7 +26,7 @@ trait ObjectToPopulateTrait
      */
     protected function extractObjectToPopulate($class, array $context, $key = null)
     {
-        $key = $key ?: 'object_to_populate';
+        $key = $key ?? AbstractNormalizer::OBJECT_TO_POPULATE;
 
         if (isset($context[$key]) && \is_object($context[$key]) && $context[$key] instanceof $class) {
             return $context[$key];

src/Symfony/Component/Serializer/Tests/Fixtures/DeepObjectPopulateChildDummy.php

@@ -0,0 +1,22 @@
+<?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\Serializer\Tests\Fixtures;
+
+/**
+ * @author Jérôme Desjardin <jewome62@gmail.com>
+ */
+class DeepObjectPopulateChildDummy
+{
+    public $foo;
+
+    public $bar;
+}

src/Symfony/Component/Serializer/Tests/Fixtures/DeepObjectPopulateParentDummy.php

@@ -0,0 +1,33 @@
+<?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\Serializer\Tests\Fixtures;
+
+/**
+ * @author Jérôme Desjardin <jewome62@gmail.com>
+ */
+class DeepObjectPopulateParentDummy
+{
+    /**
+     * @var DeepObjectPopulateChildDummy|null
+     */
+    private $child;
+
+    public function setChild(?DeepObjectPopulateChildDummy $child)
+    {
+        $this->child = $child;
+    }
+
+    public function getChild(): ?DeepObjectPopulateChildDummy
+    {
+        return $this->child;
+    }
+}

src/Symfony/Component/Serializer/Tests/Normalizer/AbstractObjectNormalizerTest.php

@@ -23,6 +23,8 @@ use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;
 use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
 use Symfony\Component\Serializer\SerializerAwareInterface;
 use Symfony\Component\Serializer\SerializerInterface;
+use Symfony\Component\Serializer\Tests\Fixtures\DeepObjectPopulateChildDummy;
+use Symfony\Component\Serializer\Tests\Fixtures\DeepObjectPopulateParentDummy;
 
 class AbstractObjectNormalizerTest extends TestCase
 {
@@ -171,6 +173,48 @@ class AbstractObjectNormalizerTest extends TestCase
         $result = $normalizer->normalize($dummy, null, [AbstractObjectNormalizer::SKIP_NULL_VALUES => true]);
         $this->assertSame(['bar' => 'present'], $result);
     }
+
+    public function testDeepObjectToPopulate()
+    {
+        $child = new DeepObjectPopulateChildDummy();
+        $child->bar = 'bar-old';
+        $child->foo = 'foo-old';
+
+        $parent = new DeepObjectPopulateParentDummy();
+        $parent->setChild($child);
+
+        $context = [
+            AbstractObjectNormalizer::OBJECT_TO_POPULATE => $parent,
+            AbstractObjectNormalizer::DEEP_OBJECT_TO_POPULATE => true,
+        ];
+
+        $classMetadataFactory = new ClassMetadataFactory(new AnnotationLoader(new AnnotationReader()));
+        $normalizer = new ObjectNormalizer($classMetadataFactory, null, null, new PhpDocExtractor());
+
+        $newChild = new DeepObjectPopulateChildDummy();
+        $newChild->bar = 'bar-new';
+        $newChild->foo = 'foo-old';
+
+        $serializer = $this->getMockBuilder(__NAMESPACE__.'\ObjectSerializerDenormalizer')->getMock();
+        $serializer
+            ->method('supportsDenormalization')
+            ->with($this->arrayHasKey('bar'),
+                $this->equalTo(DeepObjectPopulateChildDummy::class),
+                $this->isNull(),
+                $this->contains($child))
+            ->willReturn(true);
+        $serializer->method('denormalize')->willReturn($newChild);
+
+        $normalizer->setSerializer($serializer);
+        $normalizer->denormalize([
+            'child' => [
+                'bar' => 'bar-new',
+            ],
+        ], 'Symfony\Component\Serializer\Tests\Fixtures\DeepObjectPopulateParentDummy', null, $context);
+
+        $this->assertSame('bar-new', $parent->getChild()->bar);
+        $this->assertSame('foo-old', $parent->getChild()->foo);
+    }
 }
 
 class AbstractObjectNormalizerDummy extends AbstractObjectNormalizer
@@ -348,3 +392,7 @@ class ArrayDenormalizerDummy implements DenormalizerInterface, SerializerAwareIn
         $this->serializer = $serializer;
     }
 }
+
+abstract class ObjectSerializerDenormalizer implements SerializerInterface, DenormalizerInterface
+{
+}