Add a normalizer that support JsonSerializable objects

Handles circular references

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php

@@ -25,6 +25,7 @@ use Symfony\Component\HttpKernel\DependencyInjection\Extension;
 use Symfony\Component\Config\FileLocator;
 use Symfony\Component\Serializer\Normalizer\DataUriNormalizer;
 use Symfony\Component\Serializer\Normalizer\DateTimeNormalizer;
+use Symfony\Component\Serializer\Normalizer\JsonSerializableNormalizer;
 use Symfony\Component\Validator\Validation;
 
 /**
@@ -914,6 +915,13 @@ class FrameworkExtension extends Extension
             $definition->addTag('serializer.normalizer', array('priority' => -910));
         }
 
+        if (class_exists('Symfony\Component\Serializer\Normalizer\JsonSerializableNormalizer')) {
+            // Run before serializer.normalizer.object
+            $definition = $container->register('serializer.normalizer.json_serializable', JsonSerializableNormalizer::class);
+            $definition->setPublic(false);
+            $definition->addTag('serializer.normalizer', array('priority' => -900));
+        }
+
         $loader->load('serializer.xml');
         $chainLoader = $container->getDefinition('serializer.mapping.chain_loader');
 

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php

@@ -20,6 +20,7 @@ use Symfony\Component\DependencyInjection\ParameterBag\ParameterBag;
 use Symfony\Component\DependencyInjection\Reference;
 use Symfony\Component\Serializer\Normalizer\DataUriNormalizer;
 use Symfony\Component\Serializer\Normalizer\DateTimeNormalizer;
+use Symfony\Component\Serializer\Normalizer\JsonSerializableNormalizer;
 
 abstract class FrameworkExtensionTest extends TestCase
 {
@@ -485,6 +486,21 @@ abstract class FrameworkExtensionTest extends TestCase
         $this->assertEquals(-910, $tag[0]['priority']);
     }
 
+    public function testJsonNormalizerRegistered()
+    {
+        if (!class_exists('Symfony\Component\Serializer\Normalizer\JsonSerializableNormalizer')) {
+            $this->markTestSkipped('The JsonSerializableNormalizer has been introduced in the Serializer Component version 3.1.');
+        }
+
+        $container = $this->createContainerFromFile('full');
+
+        $definition = $container->getDefinition('serializer.normalizer.json');
+        $tag = $definition->getTag('serializer.normalizer');
+
+        $this->assertEquals(JsonSerializableNormalizer::class, $definition->getClass());
+        $this->assertEquals(-900, $tag[0]['priority']);
+    }
+
     public function testAssetHelperWhenAssetsAreEnabled()
     {
         $container = $this->createContainerFromFile('full');

src/Symfony/Bundle/FrameworkBundle/composer.json

@@ -46,6 +46,7 @@
         "symfony/form": "~2.8|~3.0",
         "symfony/expression-language": "~2.8|~3.0",
         "symfony/process": "~2.8|~3.0",
+        "symfony/serializer": "~2.8|^3.0",
         "symfony/validator": "~2.8|~3.0",
         "symfony/yaml": "~2.8|~3.0",
         "symfony/property-info": "~2.8|~3.0",

src/Symfony/Component/Serializer/CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+3.1.0
+-----
+
+* added support for serializing objects that implement `JsonSerializable`
+
 2.7.0
 -----
 

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

@@ -0,0 +1,67 @@
+<?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\Normalizer;
+
+use Symfony\Component\Serializer\Exception\InvalidArgumentException;
+use Symfony\Component\Serializer\Exception\LogicException;
+
+/**
+ * A normalizer that uses an objects own JsonSerializable implementation.
+ *
+ * @author Fred Cox <mcfedr@gmail.com>
+ */
+class JsonSerializableNormalizer extends AbstractNormalizer
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function normalize($object, $format = null, array $context = array())
+    {
+        if ($this->isCircularReference($object, $context)) {
+            return $this->handleCircularReference($object);
+        }
+
+        if (!$object instanceof \JsonSerializable) {
+            throw new InvalidArgumentException(sprintf('The object must implement "%s".', \JsonSerializable::class));
+        }
+
+        if (!$this->serializer instanceof NormalizerInterface) {
+            throw new LogicException('Cannot normalize object because injected serializer is not a normalizer');
+        }
+
+        return $this->serializer->normalize($object->jsonSerialize(), $format, $context);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function supportsNormalization($data, $format = null)
+    {
+        return $data instanceof \JsonSerializable;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function supportsDenormalization($data, $type, $format = null)
+    {
+        return false;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function denormalize($data, $class, $format = null, array $context = array())
+    {
+        throw new LogicException(sprintf('Cannot denormalize with "%s".', \JsonSerializable::class));
+    }
+}

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

@@ -0,0 +1,25 @@
+<?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;
+
+class JsonSerializableDummy implements \JsonSerializable
+{
+    public function jsonSerialize()
+    {
+        return array(
+            'foo' => 'a',
+            'bar' => 'b',
+            'baz' => 'c',
+            'qux' => $this,
+        );
+    }
+}

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

@@ -0,0 +1,94 @@
+<?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\Normalizer;
+
+use Symfony\Component\Serializer\Normalizer\JsonSerializableNormalizer;
+use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+use Symfony\Component\Serializer\SerializerInterface;
+use Symfony\Component\Serializer\Tests\Fixtures\JsonSerializableDummy;
+
+/**
+ * @author Fred Cox <mcfedr@gmail.com>
+ */
+class JsonSerializableNormalizerTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @var JsonSerializableNormalizer
+     */
+    private $normalizer;
+
+    /**
+     * @var \PHPUnit_Framework_MockObject_MockObject|SerializerInterface
+     */
+    private $serializer;
+
+    protected function setUp()
+    {
+        $this->serializer = $this->getMock(JsonSerializerNormalizer::class);
+        $this->normalizer = new JsonSerializableNormalizer();
+        $this->normalizer->setSerializer($this->serializer);
+    }
+
+    public function testSupportNormalization()
+    {
+        $this->assertTrue($this->normalizer->supportsNormalization(new JsonSerializableDummy()));
+        $this->assertFalse($this->normalizer->supportsNormalization(new \stdClass()));
+    }
+
+    public function testNormalize()
+    {
+        $this->serializer
+            ->expects($this->once())
+            ->method('normalize')
+            ->will($this->returnCallback(function($data) {
+                $this->assertArraySubset(array('foo' => 'a', 'bar' => 'b', 'baz' => 'c'), $data);
+
+                return 'string_object';
+            }))
+        ;
+
+        $this->assertEquals('string_object', $this->normalizer->normalize(new JsonSerializableDummy()));
+    }
+
+    /**
+     * @expectedException \Symfony\Component\Serializer\Exception\CircularReferenceException
+     */
+    public function testCircularNormalize()
+    {
+        $this->normalizer->setCircularReferenceLimit(1);
+
+        $this->serializer
+            ->expects($this->once())
+            ->method('normalize')
+            ->will($this->returnCallback(function($data, $format, $context) {
+                $this->normalizer->normalize($data['qux'], $format, $context);
+
+                return 'string_object';
+            }))
+        ;
+
+        $this->assertEquals('string_object', $this->normalizer->normalize(new JsonSerializableDummy()));
+    }
+
+    /**
+     * @expectedException \Symfony\Component\Serializer\Exception\InvalidArgumentException
+     * @expectedExceptionMessage The object must implement "JsonSerializable".
+     */
+    public function testInvalidDataThrowException()
+    {
+        $this->normalizer->normalize(new \stdClass());
+    }
+}
+
+abstract class JsonSerializerNormalizer implements SerializerInterface, NormalizerInterface
+{
+}