[Serializer] Refactoring of metadata

src/Symfony/Component/Serializer/Mapping/AttributeMetadata.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\Mapping;
+
+/**
+ * {@inheritdoc}
+ *
+ * @author Kévin Dunglas <dunglas@gmail.com>
+ */
+class AttributeMetadata implements AttributeMetadataInterface
+{
+    /**
+     * @var string
+     *
+     * @internal This property is public in order to reduce the size of the
+     *           class' serialized representation. Do not access it. Use
+     *           {@link getName()} instead.
+     */
+    public $name;
+
+    /**
+     * @var array
+     *
+     * @internal This property is public in order to reduce the size of the
+     *           class' serialized representation. Do not access it. Use
+     *           {@link getGroups()} instead.
+     */
+    public $groups = array();
+
+    /**
+     * Constructs a metadata for the given attribute.
+     *
+     * @param string $name
+     */
+    public function __construct($name)
+    {
+        $this->name = $name;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function addGroup($group)
+    {
+        if (!in_array($group, $this->groups)) {
+            $this->groups[] = $group;
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getGroups()
+    {
+        return $this->groups;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function merge(AttributeMetadataInterface $attributeMetadata)
+    {
+        foreach ($attributeMetadata->getGroups() as $group) {
+            $this->addGroup($group);
+        }
+    }
+
+    /**
+     * Returns the names of the properties that should be serialized.
+     *
+     * @return string[]
+     */
+    public function __sleep()
+    {
+        return array('name', 'groups');
+    }
+}

src/Symfony/Component/Serializer/Mapping/AttributeMetadataInterface.php

@@ -0,0 +1,50 @@
+<?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\Mapping;
+
+/**
+ * Stores metadata needed for serializing and deserializing attributes.
+ *
+ * Primarily, the metadata stores serialization groups.
+ *
+ * @author Kévin Dunglas <dunglas@gmail.com>
+ */
+interface AttributeMetadataInterface
+{
+    /**
+     * Gets the attribute name.
+     *
+     * @return string
+     */
+    public function getName();
+
+    /**
+     * Adds this attribute to the given group.
+     *
+     * @param string $group
+     */
+    public function addGroup($group);
+
+    /**
+     * Gets groups of this attribute.
+     *
+     * @return string[]
+     */
+    public function getGroups();
+
+    /**
+     * Merges an {@see AttributeMetadataInterface} with in the current one.
+     *
+     * @param AttributeMetadataInterface $attributeMetadata
+     */
+    public function merge(AttributeMetadataInterface $attributeMetadata);
+}

src/Symfony/Component/Serializer/Mapping/ClassMetadata.php

@@ -12,31 +12,29 @@
 namespace Symfony\Component\Serializer\Mapping;
 
 /**
- * Stores all metadata needed for serializing objects of specific class.
+ * {@inheritdoc}
- *
- * Primarily, the metadata stores serialization groups.
  *
  * @author Kévin Dunglas <dunglas@gmail.com>
  */
-class ClassMetadata
+class ClassMetadata implements ClassMetadataInterface
 {
     /**
      * @var string
      *
      * @internal This property is public in order to reduce the size of the
      *           class' serialized representation. Do not access it. Use
-     *           {@link getClassName()} instead.
+     *           {@link getName()} instead.
      */
     public $name;
 
     /**
-     * @var array
+     * @var AttributeMetadataInterface[]
      *
      * @internal This property is public in order to reduce the size of the
      *           class' serialized representation. Do not access it. Use
-     *           {@link getGroups()} instead.
+     *           {@link getAttributesMetadata()} instead.
      */
-    public $attributesGroups = array();
+    public $attributesMetadata = array();
 
     /**
      * @var \ReflectionClass
@@ -54,66 +52,50 @@ class ClassMetadata
     }
 
     /**
-     * Returns the name of the backing PHP class.
+     * {@inheritdoc}
-     *
-     * @return string The name of the backing class.
      */
-    public function getClassName()
+    public function getName()
     {
         return $this->name;
     }
 
     /**
-     * Gets serialization groups.
+     * {@inheritdoc}
-     *
-     * @return array
      */
-    public function getAttributesGroups()
+    public function addAttributeMetadata(AttributeMetadataInterface $attributeMetadata)
     {
-        return $this->attributesGroups;
+        $this->attributesMetadata[$attributeMetadata->getName()] = $attributeMetadata;
     }
 
     /**
-     * Adds an attribute to a serialization group
+     * {@inheritdoc}
-     *
-     * @param string $attribute
-     * @param string $group
-     * @throws \InvalidArgumentException
      */
-    public function addAttributeGroup($attribute, $group)
+    public function getAttributesMetadata()
     {
-        if (!is_string($attribute) || !is_string($group)) {
+        return $this->attributesMetadata;
-            throw new \InvalidArgumentException('Arguments must be strings.');
-        }
-
-        if (!isset($this->groups[$group]) || !in_array($attribute, $this->attributesGroups[$group])) {
-            $this->attributesGroups[$group][] = $attribute;
-        }
     }
 
     /**
-     * Merges attributes' groups.
+     * {@inheritdoc}
-     *
-     * @param ClassMetadata $classMetadata
      */
-    public function mergeAttributesGroups(ClassMetadata $classMetadata)
+    public function merge(ClassMetadataInterface $classMetadata)
     {
-        foreach ($classMetadata->getAttributesGroups() as $group => $attributes) {
+        foreach ($classMetadata->getAttributesMetadata() as $attributeMetadata) {
-            foreach ($attributes as $attribute) {
+            if (isset($this->attributesMetadata[$attributeMetadata->getName()])) {
-                $this->addAttributeGroup($attribute, $group);
+                $this->attributesMetadata[$attributeMetadata->getName()]->merge($attributeMetadata);
+            } else {
+                $this->addAttributeMetadata($attributeMetadata);
             }
         }
     }
 
     /**
-     * Returns a ReflectionClass instance for this class.
+     * {@inheritdoc}
-     *
-     * @return \ReflectionClass
      */
     public function getReflectionClass()
     {
         if (!$this->reflClass) {
-            $this->reflClass = new \ReflectionClass($this->getClassName());
+            $this->reflClass = new \ReflectionClass($this->getName());
         }
 
         return $this->reflClass;
@@ -128,7 +110,7 @@ class ClassMetadata
     {
         return array(
             'name',
-            'attributesGroups',
+            'attributes',
         );
     }
 }

src/Symfony/Component/Serializer/Mapping/ClassMetadataInterface.php

@@ -0,0 +1,57 @@
+<?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\Mapping;
+
+/**
+ * Stores metadata needed for serializing and deserializing objects of specific class.
+ *
+ * Primarily, the metadata stores the list of attributes to serialize or deserialize.
+ *
+ * @author Kévin Dunglas <dunglas@gmail.com>
+ */
+interface ClassMetadataInterface
+{
+    /**
+     * Returns the name of the backing PHP class.
+     *
+     * @return string The name of the backing class.
+     */
+    public function getName();
+
+    /**
+     * Adds an {@link AttributeMetadataInterface}.
+     *
+     * @param AttributeMetadataInterface $attributeMetadata
+     */
+    public function addAttributeMetadata(AttributeMetadataInterface $attributeMetadata);
+
+    /**
+     * Gets the list of {@link AttributeMetadataInterface}.
+     *
+     * @return AttributeMetadataInterface[]
+     */
+    public function getAttributesMetadata();
+
+    /**
+     * Merges a {@link ClassMetadataInterface} in the current one.
+     *
+     * @param ClassMetadataInterface $classMetadata
+     */
+    public function merge(ClassMetadataInterface $classMetadata);
+
+    /**
+     * Returns a {@link \ReflectionClass} instance for this class.
+     *
+     * @return \ReflectionClass
+     */
+    public function getReflectionClass();
+}

src/Symfony/Component/Serializer/Mapping/Factory/ClassMetadataFactory.php

@@ -12,6 +12,7 @@
 namespace Symfony\Component\Serializer\Mapping\Factory;
 
 use Doctrine\Common\Cache\Cache;
+use Symfony\Component\Serializer\Exception\InvalidArgumentException;
 use Symfony\Component\Serializer\Mapping\ClassMetadata;
 use Symfony\Component\Serializer\Mapping\Loader\LoaderInterface;
 
@@ -20,7 +21,7 @@ use Symfony\Component\Serializer\Mapping\Loader\LoaderInterface;
  *
  * @author Kévin Dunglas <dunglas@gmail.com>
  */
-class ClassMetadataFactory
+class ClassMetadataFactory implements ClassMetadataFactoryInterface
 {
     /**
      * @var LoaderInterface
@@ -46,29 +47,13 @@ class ClassMetadataFactory
     }
 
     /**
-     * If the method was called with the same class name (or an object of that
+     * {@inheritdoc}
-     * class) before, the same metadata instance is returned.
-     *
-     * If the factory was configured with a cache, this method will first look
-     * for an existing metadata instance in the cache. If an existing instance
-     * is found, it will be returned without further ado.
-     *
-     * Otherwise, a new metadata instance is created. If the factory was
-     * configured with a loader, the metadata is passed to the
-     * {@link LoaderInterface::loadClassMetadata()} method for further
-     * configuration. At last, the new object is returned.
-     *
-     * @param string|object $value
-     *
-     * @return ClassMetadata
-     *
-     * @throws \InvalidArgumentException
      */
     public function getMetadataFor($value)
     {
         $class = $this->getClass($value);
         if (!$class) {
-            throw new \InvalidArgumentException(sprintf('Cannot create metadata for non-objects. Got: %s', gettype($value)));
+            throw new InvalidArgumentException(sprintf('Cannot create metadata for non-objects. Got: "%s"', gettype($value)));
         }
 
         if (isset($this->loadedClasses[$class])) {
@@ -80,40 +65,33 @@ class ClassMetadataFactory
         }
 
         if (!class_exists($class) && !interface_exists($class)) {
-            throw new \InvalidArgumentException(sprintf('The class or interface "%s" does not exist.', $class));
+            throw new InvalidArgumentException(sprintf('The class or interface "%s" does not exist.', $class));
         }
 
-        $metadata = new ClassMetadata($class);
+        $classMetadata = new ClassMetadata($class);
+        $this->loader->loadClassMetadata($classMetadata);
 
-        $reflClass = $metadata->getReflectionClass();
+        $reflectionClass = $classMetadata->getReflectionClass();
 
-        // Include groups from the parent class
+        // Include metadata from the parent class
-        if ($parent = $reflClass->getParentClass()) {
+        if ($parent = $reflectionClass->getParentClass()) {
-            $metadata->mergeAttributesGroups($this->getMetadataFor($parent->name));
+            $classMetadata->merge($this->getMetadataFor($parent->name));
         }
 
-        // Include groups from all implemented interfaces
+        // Include metadata from all implemented interfaces
-        foreach ($reflClass->getInterfaces() as $interface) {
+        foreach ($reflectionClass->getInterfaces() as $interface) {
-            $metadata->mergeAttributesGroups($this->getMetadataFor($interface->name));
+            $classMetadata->merge($this->getMetadataFor($interface->name));
-        }
-
-        if ($this->loader) {
-            $this->loader->loadClassMetadata($metadata);
         }
 
         if ($this->cache) {
-            $this->cache->save($class, $metadata);
+            $this->cache->save($class, $classMetadata);
         }
 
-        return $this->loadedClasses[$class] = $metadata;
+        return $this->loadedClasses[$class] = $classMetadata;
     }
 
     /**
-     * Checks if class has metadata.
+     * {@inheritdoc}
-     *
-     * @param mixed $value
-     *
-     * @return bool
      */
     public function hasMetadataFor($value)
     {

src/Symfony/Component/Serializer/Mapping/Factory/ClassMetadataFactoryInterface.php

@@ -0,0 +1,53 @@
+<?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\Mapping\Factory;
+
+use Symfony\Component\Serializer\Exception\InvalidArgumentException;
+use Symfony\Component\Serializer\Mapping\ClassMetadataInterface;
+
+/**
+ * Returns a {@see ClassMetadataInterface}.
+ *
+ * @author Kévin Dunglas <dunglas@gmail.com>
+ */
+interface ClassMetadataFactoryInterface
+{
+    /**
+     * If the method was called with the same class name (or an object of that
+     * class) before, the same metadata instance is returned.
+     *
+     * If the factory was configured with a cache, this method will first look
+     * for an existing metadata instance in the cache. If an existing instance
+     * is found, it will be returned without further ado.
+     *
+     * Otherwise, a new metadata instance is created. If the factory was
+     * configured with a loader, the metadata is passed to the
+     * {@link LoaderInterface::loadClassMetadata()} method for further
+     * configuration. At last, the new object is returned.
+     *
+     * @param string|object $value
+     *
+     * @return ClassMetadataInterface
+     *
+     * @throws InvalidArgumentException
+     */
+    public function getMetadataFor($value);
+
+    /**
+     * Checks if class has metadata.
+     *
+     * @param mixed $value
+     *
+     * @return bool
+     */
+    public function hasMetadataFor($value);
+}

src/Symfony/Component/Serializer/Mapping/Loader/AnnotationLoader.php

@@ -14,7 +14,8 @@ namespace Symfony\Component\Serializer\Mapping\Loader;
 use Doctrine\Common\Annotations\Reader;
 use Symfony\Component\Serializer\Annotation\Groups;
 use Symfony\Component\Serializer\Exception\MappingException;
-use Symfony\Component\Serializer\Mapping\ClassMetadata;
+use Symfony\Component\Serializer\Mapping\AttributeMetadata;
+use Symfony\Component\Serializer\Mapping\ClassMetadataInterface;
 
 /**
  * Annotation loader.
@@ -39,18 +40,25 @@ class AnnotationLoader implements LoaderInterface
     /**
      * {@inheritdoc}
      */
-    public function loadClassMetadata(ClassMetadata $metadata)
+    public function loadClassMetadata(ClassMetadataInterface $classMetadata)
     {
-        $reflClass = $metadata->getReflectionClass();
+        $reflectionClass = $classMetadata->getReflectionClass();
-        $className = $reflClass->name;
+        $className = $reflectionClass->name;
         $loaded = false;
 
-        foreach ($reflClass->getProperties() as $property) {
+        $attributesMetadata = $classMetadata->getAttributesMetadata();
-            if ($property->getDeclaringClass()->name === $className) {
+
+        foreach ($reflectionClass->getProperties() as $property) {
+            if (!isset($attributeMetadata[$property->name])) {
+                $attributesMetadata[$property->name] = new AttributeMetadata($property->name);
+                $classMetadata->addAttributeMetadata($attributesMetadata[$property->name]);
+            }
+
+            if ($property->getDeclaringClass()->name == $className) {
                 foreach ($this->reader->getPropertyAnnotations($property) as $groups) {
                     if ($groups instanceof Groups) {
                         foreach ($groups->getGroups() as $group) {
-                            $metadata->addAttributeGroup($property->name, $group);
+                            $attributesMetadata[$property->name]->addGroup($group);
                         }
                     }
 
@@ -59,13 +67,22 @@ class AnnotationLoader implements LoaderInterface
             }
         }
 
-        foreach ($reflClass->getMethods() as $method) {
+        foreach ($reflectionClass->getMethods() as $method) {
-            if ($method->getDeclaringClass()->name === $className) {
+            if ($method->getDeclaringClass()->name == $className) {
                 foreach ($this->reader->getMethodAnnotations($method) as $groups) {
                     if ($groups instanceof Groups) {
                         if (preg_match('/^(get|is)(.+)$/i', $method->name, $matches)) {
+                            $attributeName = lcfirst($matches[2]);
+
+                            if (isset($attributesMetadata[$attributeName])) {
+                                $attributeMetadata = $attributesMetadata[$attributeName];
+                            } else {
+                                $attributesMetadata[$attributeName] = $attributeMetadata = new AttributeMetadata($attributeName);
+                                $classMetadata->addAttributeMetadata($attributeMetadata);
+                            }
+
                             foreach ($groups->getGroups() as $group) {
-                                $metadata->addAttributeGroup(lcfirst($matches[2]), $group);
+                                $attributeMetadata->addGroup($group);
                             }
                         } else {
                             throw new MappingException(sprintf('Groups on "%s::%s" cannot be added. Groups can only be added on methods beginning with "get" or "is".', $className, $method->name));

src/Symfony/Component/Serializer/Mapping/Loader/FileLoader.php

@@ -13,8 +13,16 @@ namespace Symfony\Component\Serializer\Mapping\Loader;
 
 use Symfony\Component\Serializer\Exception\MappingException;
 
+/**
+ * Base class for all file based loaders.
+ *
+ * @author Kévin Dunglas <dunglas@gmail.com>
+ */
 abstract class FileLoader implements LoaderInterface
 {
+    /**
+     * @var string
+     */
     protected $file;
 
     /**
@@ -22,8 +30,7 @@ abstract class FileLoader implements LoaderInterface
      *
      * @param string $file The mapping file to load
      *
-     * @throws MappingException if the mapping file does not exist
+     * @throws MappingException if the mapping file does not exist or is not readable
-     * @throws MappingException if the mapping file is not readable
      */
     public function __construct($file)
     {

src/Symfony/Component/Serializer/Mapping/Loader/LoaderChain.php

@@ -12,24 +12,28 @@
 namespace Symfony\Component\Serializer\Mapping\Loader;
 
 use Symfony\Component\Serializer\Exception\MappingException;
-use Symfony\Component\Serializer\Mapping\ClassMetadata;
+use Symfony\Component\Serializer\Mapping\ClassMetadataInterface;
 
 /**
- * Calls multiple LoaderInterface instances in a chain
+ * Calls multiple {@link LoaderInterface} instances in a chain.
  *
  * This class accepts multiple instances of LoaderInterface to be passed to the
- * constructor. When loadClassMetadata() is called, the same method is called
+ * constructor. When {@link loadClassMetadata()} is called, the same method is called
  * in <em>all</em> of these loaders, regardless of whether any of them was
  * successful or not.
  *
  * @author Bernhard Schussek <bschussek@gmail.com>
+ * @author Kévin Dunglas <dunglas@gmail.com>
  */
 class LoaderChain implements LoaderInterface
 {
-    protected $loaders;
+    /**
+     * @var LoaderInterface[]
+     */
+    private $loaders;
 
     /**
-     * Accepts a list of LoaderInterface instances
+     * Accepts a list of LoaderInterface instances.
      *
      * @param LoaderInterface[] $loaders An array of LoaderInterface instances
      *
@@ -49,7 +53,7 @@ class LoaderChain implements LoaderInterface
     /**
      * {@inheritdoc}
      */
-    public function loadClassMetadata(ClassMetadata $metadata)
+    public function loadClassMetadata(ClassMetadataInterface $metadata)
     {
         $success = false;
 

src/Symfony/Component/Serializer/Mapping/Loader/LoaderInterface.php

@@ -11,10 +11,10 @@
 
 namespace Symfony\Component\Serializer\Mapping\Loader;
 
-use Symfony\Component\Serializer\Mapping\ClassMetadata;
+use Symfony\Component\Serializer\Mapping\ClassMetadataInterface;
 
 /**
- * Loads class metadata.
+ * Loads {@link ClassMetadataInterface}.
  *
  * @author Kévin Dunglas <dunglas@gmail.com>
  */
@@ -23,9 +23,9 @@ interface LoaderInterface
     /**
      * Load class metadata.
      *
-     * @param ClassMetadata $metadata A metadata
+     * @param ClassMetadataInterface $classMetadata A metadata
      *
      * @return bool
      */
-    public function loadClassMetadata(ClassMetadata $metadata);
+    public function loadClassMetadata(ClassMetadataInterface $classMetadata);
 }

src/Symfony/Component/Serializer/Mapping/Loader/XmlFileLoader.php

@@ -13,7 +13,8 @@ namespace Symfony\Component\Serializer\Mapping\Loader;
 
 use Symfony\Component\Config\Util\XmlUtils;
 use Symfony\Component\Serializer\Exception\MappingException;
-use Symfony\Component\Serializer\Mapping\ClassMetadata;
+use Symfony\Component\Serializer\Mapping\AttributeMetadata;
+use Symfony\Component\Serializer\Mapping\ClassMetadataInterface;
 
 /**
  * Loads XML mapping files.
@@ -23,7 +24,7 @@ use Symfony\Component\Serializer\Mapping\ClassMetadata;
 class XmlFileLoader extends FileLoader
 {
     /**
-     * An array of SimpleXMLElement instances.
+     * An array of {@class \SimpleXMLElement} instances.
      *
      * @var \SimpleXMLElement[]|null
      */
@@ -32,7 +33,7 @@ class XmlFileLoader extends FileLoader
     /**
      * {@inheritdoc}
      */
-    public function loadClassMetadata(ClassMetadata $metadata)
+    public function loadClassMetadata(ClassMetadataInterface $classMetadata)
     {
         if (null === $this->classes) {
             $this->classes = array();
@@ -43,12 +44,23 @@ class XmlFileLoader extends FileLoader
             }
         }
 
-        if (isset($this->classes[$metadata->getClassName()])) {
+        $attributesMetadata = $classMetadata->getAttributesMetadata();
-            $xml = $this->classes[$metadata->getClassName()];
+
+        if (isset($this->classes[$classMetadata->getName()])) {
+            $xml = $this->classes[$classMetadata->getName()];
 
             foreach ($xml->attribute as $attribute) {
+                $attributeName = (string) $attribute['name'];
+
+                if (isset($attributesMetadata[$attributeName])) {
+                    $attributeMetadata = $attributesMetadata[$attributeName];
+                } else {
+                    $attributeMetadata = new AttributeMetadata($attributeName);
+                    $classMetadata->addAttributeMetadata($attributeMetadata);
+                }
+
                 foreach ($attribute->group as $group) {
-                    $metadata->addAttributeGroup((string) $attribute['name'], (string) $group);
+                    $attributeMetadata->addGroup((string) $group);
                 }
             }
 
@@ -59,7 +71,7 @@ class XmlFileLoader extends FileLoader
     }
 
     /**
-     * Parse a XML File.
+     * Parses a XML File.
      *
      * @param string $file Path of file
      *

src/Symfony/Component/Serializer/Mapping/Loader/YamlFileLoader.php

@@ -12,11 +12,12 @@
 namespace Symfony\Component\Serializer\Mapping\Loader;
 
 use Symfony\Component\Serializer\Exception\MappingException;
-use Symfony\Component\Serializer\Mapping\ClassMetadata;
+use Symfony\Component\Serializer\Mapping\AttributeMetadata;
+use Symfony\Component\Serializer\Mapping\ClassMetadataInterface;
 use Symfony\Component\Yaml\Parser;
 
 /**
- * YAML File Loader
+ * YAML File Loader.
  *
  * @author Kévin Dunglas <dunglas@gmail.com>
  */
@@ -34,7 +35,7 @@ class YamlFileLoader extends FileLoader
     /**
      * {@inheritdoc}
      */
-    public function loadClassMetadata(ClassMetadata $metadata)
+    public function loadClassMetadata(ClassMetadataInterface $classMetadata)
     {
         if (null === $this->classes) {
             if (!stream_is_local($this->file)) {
@@ -59,14 +60,22 @@ class YamlFileLoader extends FileLoader
             $this->classes = $classes;
         }
 
-        if (isset($this->classes[$metadata->getClassName()])) {
+        if (isset($this->classes[$classMetadata->getName()])) {
-            $yaml = $this->classes[$metadata->getClassName()];
+            $yaml = $this->classes[$classMetadata->getName()];
 
             if (isset($yaml['attributes']) && is_array($yaml['attributes'])) {
+                $attributesMetadata = $classMetadata->getAttributesMetadata();
                 foreach ($yaml['attributes'] as $attribute => $data) {
+                    if (isset($attributesMetadata[$attribute])) {
+                        $attributeMetadata = $attributesMetadata[$attribute];
+                    } else {
+                        $attributeMetadata = new AttributeMetadata($attribute);
+                        $classMetadata->addAttributeMetadata($attributeMetadata);
+                    }
+
                     if (isset($data['groups'])) {
                         foreach ($data['groups'] as $group) {
-                            $metadata->addAttributeGroup($attribute, $group);
+                            $attributeMetadata->addGroup($group);
                         }
                     }
                 }

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

@@ -15,7 +15,8 @@ use Symfony\Component\Serializer\Exception\CircularReferenceException;
 use Symfony\Component\Serializer\Exception\InvalidArgumentException;
 use Symfony\Component\Serializer\Exception\LogicException;
 use Symfony\Component\Serializer\Exception\RuntimeException;
-use Symfony\Component\Serializer\Mapping\Factory\ClassMetadataFactory;
+use Symfony\Component\Serializer\Mapping\Factory\ClassMetadataFactoryInterface;
+use Symfony\Component\Serializer\Mapping\AttributeMetadataInterface;
 use Symfony\Component\Serializer\NameConverter\CamelCaseToSnakeCaseNameConverter;
 use Symfony\Component\Serializer\NameConverter\NameConverterInterface;
 
@@ -26,21 +27,42 @@ use Symfony\Component\Serializer\NameConverter\NameConverterInterface;
  */
 abstract class AbstractNormalizer extends SerializerAwareNormalizer implements NormalizerInterface, DenormalizerInterface
 {
+    /**
+     * @var int
+     */
     protected $circularReferenceLimit = 1;
+    /**
+     * @var callable
+     */
     protected $circularReferenceHandler;
+    /**
+     * @var ClassMetadataFactoryInterface|null
+     */
     protected $classMetadataFactory;
+    /**
+     * @var NameConverterInterface|null
+     */
     protected $nameConverter;
+    /**
+     * @var array
+     */
     protected $callbacks = array();
+    /**
+     * @var array
+     */
     protected $ignoredAttributes = array();
+    /**
+     * @var array
+     */
     protected $camelizedAttributes = array();
 
     /**
-     * Sets the {@link ClassMetadataFactory} to use.
+     * Sets the {@link ClassMetadataFactoryInterface} to use.
      *
-     * @param ClassMetadataFactory|null   $classMetadataFactory
+     * @param ClassMetadataFactoryInterface|null   $classMetadataFactory
      * @param NameConverterInterface|null $nameConverter
      */
-    public function __construct(ClassMetadataFactory $classMetadataFactory = null, NameConverterInterface $nameConverter = null)
+    public function __construct(ClassMetadataFactoryInterface $classMetadataFactory = null, NameConverterInterface $nameConverter = null)
     {
         $this->classMetadataFactory = $classMetadataFactory;
         $this->nameConverter = $nameConverter;
@@ -219,19 +241,21 @@ abstract class AbstractNormalizer extends SerializerAwareNormalizer implements N
      * Gets attributes to normalize using groups.
      *
      * @param string|object $classOrObject
-     * @param array $context
+     * @param array         $context
-     * @return array|bool
+     * @param bool          $attributesAsString If false, return an array of {@link AttributeMetadataInterface}
+     *
+     * @return string[]|AttributeMetadataInterface[]|bool
      */
-    protected function getAllowedAttributes($classOrObject, array $context)
+    protected function getAllowedAttributes($classOrObject, array $context, $attributesAsString = false)
     {
         if (!$this->classMetadataFactory || !isset($context['groups']) || !is_array($context['groups'])) {
             return false;
         }
 
         $allowedAttributes = array();
-        foreach ($this->classMetadataFactory->getMetadataFor($classOrObject)->getAttributesGroups() as $group => $attributes) {
+        foreach ($this->classMetadataFactory->getMetadataFor($classOrObject)->getAttributesMetadata() as $attributeMetadata) {
-            if (in_array($group, $context['groups'])) {
+            if (count(array_intersect($attributeMetadata->getGroups(), $context['groups']))) {
-                $allowedAttributes = array_merge($allowedAttributes, $attributes);
+                $allowedAttributes[] = $attributesAsString ? $attributeMetadata->getName() : $attributeMetadata;
             }
         }
 

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

@@ -52,7 +52,7 @@ class GetSetMethodNormalizer extends AbstractNormalizer
 
         $reflectionObject = new \ReflectionObject($object);
         $reflectionMethods = $reflectionObject->getMethods(\ReflectionMethod::IS_PUBLIC);
-        $allowedAttributes = $this->getAllowedAttributes($object, $context);
+        $allowedAttributes = $this->getAllowedAttributes($object, $context, true);
 
         $attributes = array();
         foreach ($reflectionMethods as $method) {
@@ -97,7 +97,7 @@ class GetSetMethodNormalizer extends AbstractNormalizer
      */
     public function denormalize($data, $class, $format = null, array $context = array())
     {
-        $allowedAttributes = $this->getAllowedAttributes($class, $context);
+        $allowedAttributes = $this->getAllowedAttributes($class, $context, true);
         $normalizedData = $this->prepareForDenormalization($data);
 
         $reflectionClass = new \ReflectionClass($class);

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

@@ -46,7 +46,7 @@ class PropertyNormalizer extends AbstractNormalizer
 
         $reflectionObject = new \ReflectionObject($object);
         $attributes = array();
-        $allowedAttributes = $this->getAllowedAttributes($object, $context);
+        $allowedAttributes = $this->getAllowedAttributes($object, $context, true);
 
         foreach ($reflectionObject->getProperties() as $property) {
             if (in_array($property->name, $this->ignoredAttributes)) {
@@ -89,7 +89,7 @@ class PropertyNormalizer extends AbstractNormalizer
      */
     public function denormalize($data, $class, $format = null, array $context = array())
     {
-        $allowedAttributes = $this->getAllowedAttributes($class, $context);
+        $allowedAttributes = $this->getAllowedAttributes($class, $context, true);
         $data = $this->prepareForDenormalization($data);
 
         $reflectionClass = new \ReflectionClass($class);

src/Symfony/Component/Serializer/Tests/Mapping/AttributeMetadataTest.php

@@ -0,0 +1,57 @@
+<?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\Mapping;
+
+use Symfony\Component\Serializer\Mapping\AttributeMetadata;
+
+/**
+ * @author Kévin Dunglas <dunglas@gmail.com>
+ */
+class AttributeMetadataTest extends \PHPUnit_Framework_TestCase
+{
+    public function testInterface()
+    {
+        $attributeMetadata = new AttributeMetadata('name');
+        $this->assertInstanceOf('Symfony\Component\Serializer\Mapping\AttributeMetadataInterface', $attributeMetadata);
+    }
+
+    public function testGetName()
+    {
+        $attributeMetadata = new AttributeMetadata('name');
+        $this->assertEquals('name', $attributeMetadata->getName());
+    }
+
+    public function testGroups()
+    {
+        $attributeMetadata = new AttributeMetadata('group');
+        $attributeMetadata->addGroup('a');
+        $attributeMetadata->addGroup('a');
+        $attributeMetadata->addGroup('b');
+
+        $this->assertEquals(array('a', 'b'), $attributeMetadata->getGroups());
+    }
+
+    public function testMerge()
+    {
+        $attributeMetadata1 = new AttributeMetadata('a1');
+        $attributeMetadata1->addGroup('a');
+        $attributeMetadata1->addGroup('b');
+
+        $attributeMetadata2 = new AttributeMetadata('a2');
+        $attributeMetadata2->addGroup('a');
+        $attributeMetadata2->addGroup('c');
+
+        $attributeMetadata1->merge($attributeMetadata2);
+
+        $this->assertEquals(array('a', 'b', 'c'), $attributeMetadata1->getGroups());
+    }
+}

src/Symfony/Component/Serializer/Tests/Mapping/ClassMetadataTest.php

@@ -0,0 +1,65 @@
+<?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\Mapping;
+
+use Symfony\Component\Serializer\Mapping\ClassMetadata;
+
+/**
+ * @author Kévin Dunglas <dunglas@gmail.com>
+ */
+class ClassMetadataTest extends \PHPUnit_Framework_TestCase
+{
+    public function testInterface()
+    {
+        $classMetadata = new ClassMetadata('name');
+        $this->assertInstanceOf('Symfony\Component\Serializer\Mapping\ClassMetadataInterface', $classMetadata);
+    }
+
+    public function testAttributeMetadata()
+    {
+        $classMetadata = new ClassMetadata('c');
+
+        $a1 = $this->getMock('Symfony\Component\Serializer\Mapping\AttributeMetadataInterface');
+        $a1->method('getName')->willReturn('a1');
+
+        $a2 = $this->getMock('Symfony\Component\Serializer\Mapping\AttributeMetadataInterface');
+        $a2->method('getName')->willReturn('a2');
+
+        $classMetadata->addAttributeMetadata($a1);
+        $classMetadata->addAttributeMetadata($a2);
+
+        $this->assertEquals(array('a1' => $a1, 'a2' => $a2), $classMetadata->getAttributesMetadata());
+    }
+
+    public function testMerge()
+    {
+        $classMetadata1 = new ClassMetadata('c1');
+        $classMetadata2 = new ClassMetadata('c2');
+
+        $ac1 = $this->getMock('Symfony\Component\Serializer\Mapping\AttributeMetadataInterface');
+        $ac1->method('getName')->willReturn('a1');
+        $ac1->method('getGroups')->willReturn(array('a', 'b'));
+
+        $ac2 = $this->getMock('Symfony\Component\Serializer\Mapping\AttributeMetadataInterface');
+        $ac2->method('getName')->willReturn('a1');
+        $ac2->method('getGroups')->willReturn(array('b', 'c'));
+
+        $classMetadata1->addAttributeMetadata($ac1);
+        $classMetadata2->addAttributeMetadata($ac2);
+
+        $classMetadata1->merge($classMetadata2);
+
+        $ac1->method('getGroups')->willReturn('a', 'b', 'c');
+
+        $this->assertEquals(array('a1' => $ac1), $classMetadata2->getAttributesMetadata());
+    }
+}

src/Symfony/Component/Serializer/Tests/Mapping/Factory/ClassMetadataFactoryTest.php

@@ -14,21 +14,26 @@ namespace Symfony\Component\Serializer\Tests\Mapping\Factory;
 use Doctrine\Common\Annotations\AnnotationReader;
 use Symfony\Component\Serializer\Mapping\Factory\ClassMetadataFactory;
 use Symfony\Component\Serializer\Mapping\Loader\AnnotationLoader;
+use Symfony\Component\Serializer\Mapping\Loader\LoaderChain;
 use Symfony\Component\Serializer\Tests\Mapping\TestClassMetadataFactory;
 
-require_once __DIR__.'/../../../Annotation/Groups.php';
-
 /**
  * @author Kévin Dunglas <dunglas@gmail.com>
  */
 class ClassMetadataFactoryTest extends \PHPUnit_Framework_TestCase
 {
+    public function testInterface()
+    {
+        $classMetadata = new ClassMetadataFactory(new LoaderChain(array()));
+        $this->assertInstanceOf('Symfony\Component\Serializer\Mapping\Factory\ClassMetadataFactory', $classMetadata);
+    }
+
     public function testGetMetadataFor()
     {
         $factory = new ClassMetadataFactory(new AnnotationLoader(new AnnotationReader()));
-        $metadata = $factory->getMetadataFor('Symfony\Component\Serializer\Tests\Fixtures\GroupDummy');
+        $classMetadata = $factory->getMetadataFor('Symfony\Component\Serializer\Tests\Fixtures\GroupDummy');
 
-        $this->assertEquals(TestClassMetadataFactory::createClassMetadata(true, true), $metadata);
+        $this->assertEquals(TestClassMetadataFactory::createClassMetadata(true, true), $classMetadata);
     }
 
     public function testHasMetadataFor()

src/Symfony/Component/Serializer/Tests/Mapping/Loader/AnnotationLoaderTest.php

@@ -16,42 +16,51 @@ use Symfony\Component\Serializer\Mapping\ClassMetadata;
 use Symfony\Component\Serializer\Mapping\Loader\AnnotationLoader;
 use Symfony\Component\Serializer\Tests\Mapping\TestClassMetadataFactory;
 
-require_once __DIR__.'/../../../Annotation/Groups.php';
-
 /**
  * @author Kévin Dunglas <dunglas@gmail.com>
  */
 class AnnotationLoaderTest extends \PHPUnit_Framework_TestCase
 {
+    /**
+     * @var AnnotationLoader
+     */
+    private $loader;
+
+    protected function setUp()
+    {
+        $this->loader = new AnnotationLoader(new AnnotationReader());
+    }
+
+    public function testInterface()
+    {
+        $this->assertInstanceOf('Symfony\Component\Serializer\Mapping\Loader\LoaderInterface', $this->loader);
+    }
+
     public function testLoadClassMetadataReturnsTrueIfSuccessful()
     {
-        $loader = new AnnotationLoader(new AnnotationReader());
+        $classMetadata = new ClassMetadata('Symfony\Component\Serializer\Tests\Fixtures\GroupDummy');
-        $metadata = new ClassMetadata('Symfony\Component\Serializer\Tests\Fixtures\GroupDummy');
 
-        $this->assertTrue($loader->loadClassMetadata($metadata));
+        $this->assertTrue($this->loader->loadClassMetadata($classMetadata));
     }
 
     public function testLoadClassMetadata()
     {
-        $loader = new AnnotationLoader(new AnnotationReader());
+        $classMetadata = new ClassMetadata('Symfony\Component\Serializer\Tests\Fixtures\GroupDummy');
-        $metadata = new ClassMetadata('Symfony\Component\Serializer\Tests\Fixtures\GroupDummy');
+        $this->loader->loadClassMetadata($classMetadata);
 
-        $loader->loadClassMetadata($metadata);
+        $this->assertEquals(TestClassMetadataFactory::createClassMetadata(), $classMetadata);
-
-        $this->assertEquals(TestClassMetadataFactory::createClassMetadata(), $metadata);
     }
 
     public function testLoadClassMetadataAndMerge()
     {
-        $loader = new AnnotationLoader(new AnnotationReader());
+        $classMetadata = new ClassMetadata('Symfony\Component\Serializer\Tests\Fixtures\GroupDummy');
-        $metadata = new ClassMetadata('Symfony\Component\Serializer\Tests\Fixtures\GroupDummy');
+        $parentClassMetadata = new ClassMetadata('Symfony\Component\Serializer\Tests\Fixtures\GroupDummyParent');
-        $parentMetadata = new ClassMetadata('Symfony\Component\Serializer\Tests\Fixtures\GroupDummyParent');
 
-        $loader->loadClassMetadata($parentMetadata);
+        $this->loader->loadClassMetadata($parentClassMetadata);
-        $metadata->mergeAttributesGroups($parentMetadata);
+        $classMetadata->merge($parentClassMetadata);
 
-        $loader->loadClassMetadata($metadata);
+        $this->loader->loadClassMetadata($classMetadata);
 
-        $this->assertEquals(TestClassMetadataFactory::createClassMetadata(true), $metadata);
+        $this->assertEquals(TestClassMetadataFactory::createClassMetadata(true), $classMetadata);
     }
 }

src/Symfony/Component/Serializer/Tests/Mapping/Loader/XmlFileLoaderTest.php

@@ -20,7 +20,13 @@ use Symfony\Component\Serializer\Tests\Mapping\TestClassMetadataFactory;
  */
 class XmlFileLoaderTest extends \PHPUnit_Framework_TestCase
 {
+    /**
+     * @var XmlFileLoader
+     */
     private $loader;
+    /**
+     * @var ClassMetadata
+     */
     private $metadata;
 
     public function setUp()
@@ -29,6 +35,11 @@ class XmlFileLoaderTest extends \PHPUnit_Framework_TestCase
         $this->metadata = new ClassMetadata('Symfony\Component\Serializer\Tests\Fixtures\GroupDummy');
     }
 
+    public function testInterface()
+    {
+        $this->assertInstanceOf('Symfony\Component\Serializer\Mapping\Loader\LoaderInterface', $this->loader);
+    }
+
     public function testLoadClassMetadataReturnsTrueIfSuccessful()
     {
         $this->assertTrue($this->loader->loadClassMetadata($this->metadata));

src/Symfony/Component/Serializer/Tests/Mapping/Loader/YamlFileLoaderTest.php

@@ -20,7 +20,13 @@ use Symfony\Component\Serializer\Tests\Mapping\TestClassMetadataFactory;
  */
 class YamlFileLoaderTest extends \PHPUnit_Framework_TestCase
 {
+    /**
+     * @var YamlFileLoader
+     */
     private $loader;
+    /**
+     * @var ClassMetadata
+     */
     private $metadata;
 
     public function setUp()
@@ -29,6 +35,11 @@ class YamlFileLoaderTest extends \PHPUnit_Framework_TestCase
         $this->metadata = new ClassMetadata('Symfony\Component\Serializer\Tests\Fixtures\GroupDummy');
     }
 
+    public function testInterface()
+    {
+        $this->assertInstanceOf('Symfony\Component\Serializer\Mapping\Loader\LoaderInterface', $this->loader);
+    }
+
     public function testLoadClassMetadataReturnsTrueIfSuccessful()
     {
         $this->assertTrue($this->loader->loadClassMetadata($this->metadata));

src/Symfony/Component/Serializer/Tests/Mapping/TestClassMetadataFactory.php

@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\Serializer\Tests\Mapping;
 
+use Symfony\Component\Serializer\Mapping\AttributeMetadata;
 use Symfony\Component\Serializer\Mapping\ClassMetadata;
 
 /**
@@ -22,22 +23,38 @@ class TestClassMetadataFactory
     {
         $expected = new ClassMetadata('Symfony\Component\Serializer\Tests\Fixtures\GroupDummy');
 
+        $foo = new AttributeMetadata('foo');
+        $foo->addGroup('a');
+        $expected->addAttributeMetadata($foo);
+
+        $bar = new AttributeMetadata('bar');
+        $bar->addGroup('b');
+        $bar->addGroup('c');
+        $expected->addAttributeMetadata($bar);
+
+        $fooBar = new AttributeMetadata('fooBar');
+        $fooBar->addGroup('a');
+        $fooBar->addGroup('b');
+        $expected->addAttributeMetadata($fooBar);
+
+        $symfony = new AttributeMetadata('symfony');
+        $expected->addAttributeMetadata($symfony);
+
         if ($withParent) {
-            $expected->addAttributeGroup('kevin', 'a');
+            $kevin = new AttributeMetadata('kevin');
-            $expected->addAttributeGroup('coopTilleuls', 'a');
+            $kevin->addGroup('a');
-            $expected->addAttributeGroup('coopTilleuls', 'b');
+            $expected->addAttributeMetadata($kevin);
+
+            $coopTilleuls = new AttributeMetadata('coopTilleuls');
+            $coopTilleuls->addGroup('a');
+            $coopTilleuls->addGroup('b');
+            $expected->addAttributeMetadata($coopTilleuls);
         }
 
         if ($withInterface) {
-            $expected->addAttributeGroup('symfony', 'a');
+            $symfony->addGroup('a');
         }
 
-        $expected->addAttributeGroup('foo', 'a');
-        $expected->addAttributeGroup('bar', 'b');
-        $expected->addAttributeGroup('bar', 'c');
-        $expected->addAttributeGroup('fooBar', 'a');
-        $expected->addAttributeGroup('fooBar', 'b');
-
         // load reflection class so that the comparison passes
         $expected->getReflectionClass();
 
@@ -47,9 +64,15 @@ class TestClassMetadataFactory
     public static function createXmlCLassMetadata()
     {
         $expected = new ClassMetadata('Symfony\Component\Serializer\Tests\Fixtures\GroupDummy');
-        $expected->addAttributeGroup('foo', 'group1');
+
-        $expected->addAttributeGroup('foo', 'group2');
+        $foo = new AttributeMetadata('foo');
-        $expected->addAttributeGroup('bar', 'group2');
+        $foo->addGroup('group1');
+        $foo->addGroup('group2');
+        $expected->addAttributeMetadata($foo);
+
+        $bar = new AttributeMetadata('bar');
+        $bar->addGroup('group2');
+        $expected->addAttributeMetadata($bar);
 
         return $expected;
     }

src/Symfony/Component/Serializer/Tests/NameConverter/CamelCaseToSnakeCaseNameConverterTest.php

@@ -18,6 +18,12 @@ use Symfony\Component\Serializer\NameConverter\CamelCaseToSnakeCaseNameConverter
  */
 class CamelCaseToSnakeCaseNameConverterTest extends \PHPUnit_Framework_TestCase
 {
+    public function testInterface()
+    {
+        $attributeMetadata = new CamelCaseToSnakeCaseNameConverter();
+        $this->assertInstanceOf('Symfony\Component\Serializer\NameConverter\NameConverterInterface', $attributeMetadata);
+    }
+
     /**
      * @dataProvider attributeProvider
      */

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

@@ -17,12 +17,23 @@ use Symfony\Component\Serializer\Serializer;
 
 class CustomNormalizerTest extends \PHPUnit_Framework_TestCase
 {
+    /**
+     * @var CustomNormalizer
+     */
+    private $normalizer;
+
     protected function setUp()
     {
         $this->normalizer = new CustomNormalizer();
         $this->normalizer->setSerializer(new Serializer());
     }
 
+    public function testInterface()
+    {
+        $this->assertInstanceOf('Symfony\Component\Serializer\Normalizer\NormalizerInterface', $this->normalizer);
+        $this->assertInstanceOf('Symfony\Component\Serializer\Normalizer\DenormalizerInterface', $this->normalizer);
+    }
+
     public function testSerialize()
     {
         $obj = new ScalarDummy();

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

@@ -40,6 +40,12 @@ class GetSetMethodNormalizerTest extends \PHPUnit_Framework_TestCase
         $this->normalizer->setSerializer($this->serializer);
     }
 
+    public function testInterface()
+    {
+        $this->assertInstanceOf('Symfony\Component\Serializer\Normalizer\NormalizerInterface', $this->normalizer);
+        $this->assertInstanceOf('Symfony\Component\Serializer\Normalizer\DenormalizerInterface', $this->normalizer);
+    }
+
     public function testNormalize()
     {
         $obj = new GetSetDummy();

src/Symfony/Component/Serializer/Tests/SerializerTest.php

@@ -22,6 +22,17 @@ use Symfony\Component\Serializer\Tests\Normalizer\TestDenormalizer;
 
 class SerializerTest extends \PHPUnit_Framework_TestCase
 {
+    public function testInterface()
+    {
+        $serializer = new Serializer();
+
+        $this->assertInstanceOf('Symfony\Component\Serializer\SerializerInterface', $serializer);
+        $this->assertInstanceOf('Symfony\Component\Serializer\Normalizer\NormalizerInterface', $serializer);
+        $this->assertInstanceOf('Symfony\Component\Serializer\Normalizer\DenormalizerInterface', $serializer);
+        $this->assertInstanceOf('Symfony\Component\Serializer\Encoder\EncoderInterface', $serializer);
+        $this->assertInstanceOf('Symfony\Component\Serializer\Encoder\DecoderInterface', $serializer);
+    }
+
     /**
      * @expectedException \Symfony\Component\Serializer\Exception\UnexpectedValueException
      */