caore d8 files

core/modules/serialization/src/Encoder/JsonEncoder.php

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+<?php
+
+namespace Drupal\serialization\Encoder;
+
+use Symfony\Component\Serializer\Encoder\DecoderInterface;
+use Symfony\Component\Serializer\Encoder\EncoderInterface;
+use Symfony\Component\Serializer\Encoder\JsonEncoder as BaseJsonEncoder;
+
+/**
+ * Adds 'ajax to the supported content types of the JSON encoder'
+ */
+class JsonEncoder extends BaseJsonEncoder implements EncoderInterface, DecoderInterface {
+
+  /**
+   * The formats that this Encoder supports.
+   *
+   * @var array
+   */
+  protected static $format = array('json', 'ajax');
+
+  /**
+   * {@inheritdoc}
+   */
+  public function supportsEncoding($format) {
+    return in_array($format, static::$format);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function supportsDecoding($format) {
+    return in_array($format, static::$format);
+  }
+
+}

core/modules/serialization/src/Encoder/XmlEncoder.php

@@ -0,0 +1,82 @@
+<?php
+
+namespace Drupal\serialization\Encoder;
+
+use Symfony\Component\Serializer\Encoder\EncoderInterface;
+use Symfony\Component\Serializer\Encoder\DecoderInterface;
+use Symfony\Component\Serializer\Encoder\XmlEncoder as BaseXmlEncoder;
+
+/**
+ * Adds XML support for serializer.
+ *
+ * This acts as a wrapper class for Symfony's XmlEncoder so that it is not
+ * implementing NormalizationAwareInterface, and can be normalized externally.
+ */
+class XmlEncoder implements EncoderInterface, DecoderInterface {
+
+  /**
+   * The formats that this Encoder supports.
+   *
+   * @var array
+   */
+  static protected $format = array('xml');
+
+  /**
+   * An instance of the Symfony XmlEncoder to perform the actual encoding.
+   *
+   * @var \Symfony\Component\Serializer\Encoder\XmlEncoder
+   */
+  protected $baseEncoder;
+
+  /**
+   * Gets the base encoder instance.
+   *
+   * @return \Symfony\Component\Serializer\Encoder\XmlEncoder
+   *   The base encoder.
+   */
+  public function getBaseEncoder() {
+    if (!isset($this->baseEncoder)) {
+      $this->baseEncoder = new BaseXmlEncoder();
+    }
+
+    return $this->baseEncoder;
+  }
+
+  /**
+   * Sets the base encoder instance.
+   *
+   * @param \Symfony\Component\Serializer\Encoder\XmlEncoder $encoder
+   */
+  public function setBaseEncoder($encoder) {
+    $this->baseEncoder = $encoder;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function encode($data, $format, array $context = array()){
+    return $this->getBaseEncoder()->encode($data, $format, $context);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function supportsEncoding($format) {
+    return in_array($format, static::$format);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function decode($data, $format, array $context = array()){
+    return $this->getBaseEncoder()->decode($data, $format, $context);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function supportsDecoding($format) {
+    return in_array($format, static::$format);
+  }
+
+}

core/modules/serialization/src/EntityResolver/ChainEntityResolver.php

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+<?php
+
+namespace Drupal\serialization\EntityResolver;
+
+use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+
+/**
+ * Resolver delegating the entity resolution to a chain of resolvers.
+ */
+class ChainEntityResolver implements ChainEntityResolverInterface {
+
+  /**
+   * The concrete resolvers.
+   *
+   * @var \Drupal\serialization\EntityResolver\EntityResolverInterface[]
+   */
+  protected $resolvers = array();
+
+  /**
+   * Constructs a ChainEntityResolver object.
+   *
+   * @param \Drupal\serialization\EntityResolver\EntityResolverInterface[] $resolvers
+   *   The array of concrete resolvers.
+   */
+  public function __construct(array $resolvers = array()) {
+    $this->resolvers = $resolvers;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function addResolver(EntityResolverInterface $resolver) {
+    $this->resolvers[] = $resolver;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function resolve(NormalizerInterface $normalizer, $data, $entity_type) {
+    foreach ($this->resolvers as $resolver) {
+      $resolved = $resolver->resolve($normalizer, $data, $entity_type);
+      if (isset($resolved)) {
+        return $resolved;
+      }
+    }
+  }
+
+}

core/modules/serialization/src/EntityResolver/ChainEntityResolverInterface.php

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+<?php
+
+namespace Drupal\serialization\EntityResolver;
+
+/**
+ * An interface for delegating a entity resolution to a chain of resolvers.
+ */
+interface ChainEntityResolverInterface extends EntityResolverInterface {
+
+  /**
+   * Adds an entity resolver.
+   *
+   * @param \Drupal\serialization\EntityResolver\EntityResolverInterface $resolver
+   *   The entity resolver to add.
+   */
+  public function addResolver(EntityResolverInterface $resolver);
+
+}

core/modules/serialization/src/EntityResolver/EntityResolverInterface.php

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+<?php
+
+namespace Drupal\serialization\EntityResolver;
+
+use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+
+interface EntityResolverInterface {
+
+  /**
+   * Returns the local ID of an entity referenced by serialized data.
+   *
+   * Drupal entities are loaded by and internally referenced by a local ID.
+   * Because different websites can use the same local ID to refer to different
+   * entities (e.g., node "1" can be a different node on foo.com and bar.com, or
+   * on example.com and staging.example.com), it is generally unsuitable for use
+   * in hypermedia data exchanges. Instead, UUIDs, URIs, or other globally
+   * unique IDs are preferred.
+   *
+   * This function takes a $data array representing partially deserialized data
+   * for an entity reference, and resolves it to a local entity ID. For example,
+   * depending on the data specification being used, $data might contain a
+   * 'uuid' key, a 'uri' key, a 'href' key, or some other data identifying the
+   * entity, and it is up to the implementor of this interface to resolve that
+   * appropriately for the specification being used.
+   *
+   * @param \Symfony\Component\Serializer\Normalizer\NormalizerInterface $normalizer
+   *   The Normalizer which is handling the data.
+   * @param array $data
+   *   The data passed into the calling Normalizer.
+   * @param string $entity_type
+   *   The type of entity being resolved; e.g., 'node' or 'user'.
+   *
+   * @return string|null
+   *   Returns the local entity ID, if found. Otherwise, returns NULL.
+   */
+  public function resolve(NormalizerInterface $normalizer, $data, $entity_type);
+
+}

core/modules/serialization/src/EntityResolver/TargetIdResolver.php

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+<?php
+
+namespace Drupal\serialization\EntityResolver;
+
+use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+
+/**
+ * Resolves entities from data that contains an entity target ID.
+ */
+class TargetIdResolver implements EntityResolverInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function resolve(NormalizerInterface $normalizer, $data, $entity_type) {
+    if (isset($data['target_id'])) {
+      return $data['target_id'];
+    }
+    return NULL;
+  }
+
+}

core/modules/serialization/src/EntityResolver/UuidReferenceInterface.php

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+<?php
+
+namespace Drupal\serialization\EntityResolver;
+
+use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+
+/**
+ * Interface for extracting UUID from entity reference data when denormalizing.
+ */
+interface UuidReferenceInterface extends NormalizerInterface {
+
+  /**
+   * Get the uuid from the data array.
+   *
+   * @param array $data
+   *   The data, as was passed into the Normalizer.
+   *
+   * @return string
+   *   A UUID.
+   */
+  public function getUuid($data);
+
+}

core/modules/serialization/src/EntityResolver/UuidResolver.php

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+<?php
+
+namespace Drupal\serialization\EntityResolver;
+
+use Drupal\Core\Entity\EntityManagerInterface;
+use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+
+/**
+ * Resolves entities from data that contains an entity UUID.
+ */
+class UuidResolver implements EntityResolverInterface {
+
+  /**
+   * The entity manager.
+   *
+   * @var \Drupal\Core\Entity\EntityManagerInterface
+   */
+  protected $entityManager;
+
+  /**
+   * Constructs a UuidResolver object.
+   *
+   * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
+   *   The entity manager.
+   */
+  public function __construct(EntityManagerInterface $entity_manager) {
+    $this->entityManager = $entity_manager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function resolve(NormalizerInterface $normalizer, $data, $entity_type) {
+    // The normalizer is what knows the specification of the data being
+    // deserialized. If it can return a UUID from that data, and if there's an
+    // entity with that UUID, then return its ID.
+    if (($normalizer instanceof UuidReferenceInterface) && ($uuid = $normalizer->getUuid($data))) {
+      if ($entity = $this->entityManager->loadEntityByUuid($entity_type, $uuid)) {
+        return $entity->id();
+      }
+    }
+    return NULL;
+  }
+
+}

core/modules/serialization/src/Normalizer/ComplexDataNormalizer.php

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+<?php
+
+namespace Drupal\serialization\Normalizer;
+
+/**
+ * Converts the Drupal entity object structures to a normalized array.
+ *
+ * This is the default Normalizer for entities. All formats that have Encoders
+ * registered with the Serializer in the DIC will be normalized with this
+ * class unless another Normalizer is registered which supersedes it. If a
+ * module wants to use format-specific or class-specific normalization, then
+ * that module can register a new Normalizer and give it a higher priority than
+ * this one.
+ */
+class ComplexDataNormalizer extends NormalizerBase {
+
+  /**
+   * The interface or class that this Normalizer supports.
+   *
+   * @var string
+   */
+  protected $supportedInterfaceOrClass = 'Drupal\Core\TypedData\ComplexDataInterface';
+
+  /**
+   * {@inheritdoc}
+   */
+  public function normalize($object, $format = NULL, array $context = array()) {
+    $attributes = array();
+    foreach ($object as $name => $field) {
+      $attributes[$name] = $this->serializer->normalize($field, $format, $context);
+    }
+    return $attributes;
+  }
+
+}

core/modules/serialization/src/Normalizer/ConfigEntityNormalizer.php

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+<?php
+
+namespace Drupal\serialization\Normalizer;
+
+/**
+ * Normalizes/denormalizes Drupal config entity objects into an array structure.
+ */
+class ConfigEntityNormalizer extends EntityNormalizer {
+
+  /**
+   * The interface or class that this Normalizer supports.
+   *
+   * @var array
+   */
+  protected $supportedInterfaceOrClass = array('Drupal\Core\Config\Entity\ConfigEntityInterface');
+
+  /**
+   * {@inheritdoc}
+   */
+  public function normalize($object, $format = NULL, array $context = array()) {
+    return $object->toArray();
+  }
+
+}

core/modules/serialization/src/Normalizer/ContentEntityNormalizer.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace Drupal\serialization\Normalizer;
+
+/**
+ * Normalizes/denormalizes Drupal content entities into an array structure.
+ */
+class ContentEntityNormalizer extends EntityNormalizer {
+
+  /**
+   * The interface or class that this Normalizer supports.
+   *
+   * @var array
+   */
+  protected $supportedInterfaceOrClass = ['Drupal\Core\Entity\ContentEntityInterface'];
+
+  /**
+   * {@inheritdoc}
+   */
+  public function normalize($object, $format = NULL, array $context = array()) {
+    $context += array(
+      'account' => NULL,
+    );
+
+    $attributes = [];
+    foreach ($object as $name => $field) {
+      if ($field->access('view', $context['account'])) {
+        $attributes[$name] = $this->serializer->normalize($field, $format, $context);
+      }
+    }
+
+    return $attributes;
+  }
+
+}

core/modules/serialization/src/Normalizer/EntityNormalizer.php

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+<?php
+
+namespace Drupal\serialization\Normalizer;
+
+use Drupal\Core\Entity\EntityManagerInterface;
+use Symfony\Component\Serializer\Exception\UnexpectedValueException;
+use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;
+
+/**
+ * Normalizes/denormalizes Drupal entity objects into an array structure.
+ */
+class EntityNormalizer extends ComplexDataNormalizer implements DenormalizerInterface {
+
+  /**
+   * The interface or class that this Normalizer supports.
+   *
+   * @var array
+   */
+  protected $supportedInterfaceOrClass = array('Drupal\Core\Entity\EntityInterface');
+
+  /**
+   * The entity manager.
+   *
+   * @var \Drupal\Core\Entity\EntityManagerInterface
+   */
+  protected $entityManager;
+
+  /**
+   * Constructs an EntityNormalizer object.
+   *
+   * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
+   *   The entity manager.
+   */
+  public function __construct(EntityManagerInterface $entity_manager) {
+    $this->entityManager = $entity_manager;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function denormalize($data, $class, $format = NULL, array $context = []) {
+    // Get the entity type ID while letting context override the $class param.
+    $entity_type_id = !empty($context['entity_type']) ? $context['entity_type'] : $this->entityManager->getEntityTypeFromClass($class);
+
+    /** @var \Drupal\Core\Entity\EntityTypeInterface $entity_type_definition */
+    // Get the entity type definition.
+    $entity_type_definition = $this->entityManager->getDefinition($entity_type_id, FALSE);
+
+    // Don't try to create an entity without an entity type id.
+    if (!$entity_type_definition) {
+      throw new UnexpectedValueException(sprintf('The specified entity type "%s" does not exist. A valid etnity type is required for denormalization', $entity_type_id));
+    }
+
+    // The bundle property will be required to denormalize a bundleable entity.
+    if ($entity_type_definition->hasKey('bundle')) {
+      $bundle_key = $entity_type_definition->getKey('bundle');
+      // Get the base field definitions for this entity type.
+      $base_field_definitions = $this->entityManager->getBaseFieldDefinitions($entity_type_id);
+
+      // Get the ID key from the base field definition for the bundle key or
+      // default to 'value'.
+      $key_id = isset($base_field_definitions[$bundle_key]) ? $base_field_definitions[$bundle_key]->getFieldStorageDefinition()->getMainPropertyName() : 'value';
+
+      // Normalize the bundle if it is not explicitly set.
+      $data[$bundle_key] = isset($data[$bundle_key][0][$key_id]) ? $data[$bundle_key][0][$key_id] : (isset($data[$bundle_key]) ? $data[$bundle_key] : NULL);
+
+      // Get the bundle entity type from the entity type definition.
+      $bundle_type_id = $entity_type_definition->getBundleEntityType();
+      $bundle_types = $bundle_type_id ? $this->entityManager->getStorage($bundle_type_id)->getQuery()->execute() : [];
+
+      // Make sure a bundle has been provided.
+      if (!is_string($data[$bundle_key])) {
+        throw new UnexpectedValueException('A string must be provided as a bundle value.');
+      }
+
+      // Make sure the submitted bundle is a valid bundle for the entity type.
+      if ($bundle_types && !in_array($data[$bundle_key], $bundle_types)) {
+        throw new UnexpectedValueException(sprintf('"%s" is not a valid bundle type for denormalization.', $data[$bundle_key]));
+      }
+    }
+
+    // Create the entity from data.
+    $entity = $this->entityManager->getStorage($entity_type_id)->create($data);
+
+    // Pass the names of the fields whose values can be merged.
+    // @todo https://www.drupal.org/node/2456257 remove this.
+    $entity->_restSubmittedFields = array_keys($data);
+
+    return $entity;
+  }
+
+}

core/modules/serialization/src/Normalizer/EntityReferenceFieldItemNormalizer.php

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+<?php
+
+namespace Drupal\serialization\Normalizer;
+
+use Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem;
+
+/**
+ * Adds the file URI to embedded file entities.
+ */
+class EntityReferenceFieldItemNormalizer extends ComplexDataNormalizer {
+
+  /**
+   * The interface or class that this Normalizer supports.
+   *
+   * @var string
+   */
+  protected $supportedInterfaceOrClass = EntityReferenceItem::class;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function normalize($field_item, $format = NULL, array $context = []) {
+    $values = parent::normalize($field_item, $format, $context);
+
+    /** @var \Drupal\Core\Entity\EntityInterface $entity */
+    if ($entity = $field_item->get('entity')->getValue()) {
+      $values['target_type'] = $entity->getEntityTypeId();
+      // Add the target entity UUID to the normalized output values.
+      $values['target_uuid'] = $entity->uuid();
+
+      // Add a 'url' value if there is a reference and a canonical URL. Hard
+      // code 'canonical' here as config entities override the default $rel
+      // parameter value to 'edit-form.
+      if ($url = $entity->url('canonical')) {
+        $values['url'] = $url;
+      }
+    }
+
+    return $values;
+  }
+
+}

core/modules/serialization/src/Normalizer/ListNormalizer.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Drupal\serialization\Normalizer;
+
+/**
+ * Converts list objects to arrays.
+ *
+ * Ordinarily, this would be handled automatically by Serializer, but since
+ * there is a TypedDataNormalizer and the Field class extends TypedData, any
+ * Field will be handled by that Normalizer instead of being traversed. This
+ * class ensures that TypedData classes that also implement ListInterface are
+ * traversed instead of simply returning getValue().
+ */
+class ListNormalizer extends NormalizerBase {
+
+  /**
+   * The interface or class that this Normalizer supports.
+   *
+   * @var string
+   */
+  protected $supportedInterfaceOrClass = 'Drupal\Core\TypedData\ListInterface';
+
+  /**
+   * {@inheritdoc}
+   */
+  public function normalize($object, $format = NULL, array $context = array()) {
+    $attributes = array();
+    foreach ($object as $fieldItem) {
+      $attributes[] = $this->serializer->normalize($fieldItem, $format);
+    }
+    return $attributes;
+  }
+
+}

core/modules/serialization/src/Normalizer/MarkupNormalizer.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace Drupal\serialization\Normalizer;
+
+/**
+ * Normalizes MarkupInterface objects into a string.
+ */
+class MarkupNormalizer extends NormalizerBase {
+
+  /**
+   * The interface or class that this Normalizer supports.
+   *
+   * @var array
+   */
+  protected $supportedInterfaceOrClass = array('Drupal\Component\Render\MarkupInterface');
+
+  /**
+   * {@inheritdoc}
+   */
+  public function normalize($object, $format = NULL, array $context = array()) {
+    return (string) $object;
+  }
+
+}

core/modules/serialization/src/Normalizer/NormalizerBase.php

@@ -0,0 +1,77 @@
+<?php
+
+namespace Drupal\serialization\Normalizer;
+
+use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+use Symfony\Component\Serializer\Normalizer\SerializerAwareNormalizer;
+
+/**
+ * Base class for Normalizers.
+ */
+abstract class NormalizerBase extends SerializerAwareNormalizer implements NormalizerInterface {
+
+  /**
+   * The interface or class that this Normalizer supports.
+   *
+   * @var string|array
+   */
+  protected $supportedInterfaceOrClass;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function supportsNormalization($data, $format = NULL) {
+    // If we aren't dealing with an object or the format is not supported return
+    // now.
+    if (!is_object($data) || !$this->checkFormat($format)) {
+      return FALSE;
+    }
+
+    $supported = (array) $this->supportedInterfaceOrClass;
+
+    return (bool) array_filter($supported, function($name) use ($data) {
+      return $data instanceof $name;
+    });
+  }
+
+  /**
+   * Implements \Symfony\Component\Serializer\Normalizer\DenormalizerInterface::supportsDenormalization()
+   *
+   * This class doesn't implement DenormalizerInterface, but most of its child
+   * classes do, so this method is implemented at this level to reduce code
+   * duplication.
+   */
+  public function supportsDenormalization($data, $type, $format = NULL) {
+    // If the format is not supported return now.
+    if (!$this->checkFormat($format)) {
+      return FALSE;
+    }
+
+    $supported = (array) $this->supportedInterfaceOrClass;
+
+    $subclass_check = function($name) use ($type) {
+      return (class_exists($name) || interface_exists($name)) && is_subclass_of($type, $name, TRUE);
+    };
+
+    return in_array($type, $supported) || array_filter($supported, $subclass_check);
+  }
+
+  /**
+   * Checks if the provided format is supported by this normalizer.
+   *
+   * @param string $format
+   *   The format to check.
+   *
+   * @return bool
+   *   TRUE if the format is supported, FALSE otherwise. If no format is
+   *   specified this will return TRUE.
+   */
+  protected function checkFormat($format = NULL) {
+    if (!isset($format) || !isset($this->format)) {
+      return TRUE;
+    }
+
+    return in_array($format, (array) $this->format);
+   }
+
+}

core/modules/serialization/src/Normalizer/NullNormalizer.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Drupal\serialization\Normalizer;
+
+/**
+ * Null normalizer.
+ */
+class NullNormalizer extends NormalizerBase {
+
+  /**
+   * Constructs a NullNormalizer object.
+   *
+   * @param string|array $supported_interface_of_class
+   *   The supported interface(s) or class(es).
+   */
+  public function __construct($supported_interface_of_class) {
+    $this->supportedInterfaceOrClass = $supported_interface_of_class;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function normalize($object, $format = NULL, array $context = array()) {
+    return NULL;
+  }
+
+}

core/modules/serialization/src/Normalizer/TypedDataNormalizer.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace Drupal\serialization\Normalizer;
+
+/**
+ * Converts typed data objects to arrays.
+ */
+class TypedDataNormalizer extends NormalizerBase {
+
+  /**
+   * The interface or class that this Normalizer supports.
+   *
+   * @var string
+   */
+  protected $supportedInterfaceOrClass = 'Drupal\Core\TypedData\TypedDataInterface';
+
+  /**
+   * {@inheritdoc}
+   */
+  public function normalize($object, $format = NULL, array $context = array()) {
+    return $object->getValue();
+  }
+
+}

core/modules/serialization/src/RegisterEntityResolversCompilerPass.php

@@ -0,0 +1,62 @@
+<?php
+
+namespace Drupal\serialization;
+
+use Symfony\Component\DependencyInjection\Reference;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
+
+/**
+ * Adds services tagged 'normalizer' and 'encoder' to the Serializer.
+ */
+class RegisterEntityResolversCompilerPass implements CompilerPassInterface {
+
+  /**
+   * Adds services to the Serializer.
+   *
+   * @param \Symfony\Component\DependencyInjection\ContainerBuilder $container
+   *   The container to process.
+   */
+  public function process(ContainerBuilder $container) {
+    $definition = $container->getDefinition('serializer.entity_resolver');
+    $resolvers = array();
+
+    // Retrieve registered Normalizers and Encoders from the container.
+    foreach ($container->findTaggedServiceIds('entity_resolver') as $id => $attributes) {
+      $priority = isset($attributes[0]['priority']) ? $attributes[0]['priority'] : 0;
+      $resolvers[$priority][] = new Reference($id);
+    }
+
+    // Add the registered concrete EntityResolvers to the ChainEntityResolver.
+    foreach ($this->sort($resolvers) as $resolver) {
+      $definition->addMethodCall('addResolver', array($resolver));
+    }
+  }
+
+  /**
+   * Sorts by priority.
+   *
+   * Order services from highest priority number to lowest (reverse sorting).
+   *
+   * @param array $services
+   *   A nested array keyed on priority number. For each priority number, the
+   *   value is an array of Symfony\Component\DependencyInjection\Reference
+   *   objects, each a reference to a normalizer or encoder service.
+   *
+   * @return array
+   *   A flattened array of Reference objects from $services, ordered from high
+   *   to low priority.
+   */
+  protected function sort($services) {
+    $sorted = array();
+    krsort($services);
+
+    // Flatten the array.
+    foreach ($services as $a) {
+      $sorted = array_merge($sorted, $a);
+    }
+
+    return $sorted;
+  }
+
+}

core/modules/serialization/src/RegisterSerializationClassesCompilerPass.php

@@ -0,0 +1,75 @@
+<?php
+
+namespace Drupal\serialization;
+
+use Symfony\Component\DependencyInjection\Reference;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
+
+/**
+ * Adds services tagged 'normalizer' and 'encoder' to the Serializer.
+ */
+class RegisterSerializationClassesCompilerPass implements CompilerPassInterface {
+
+  /**
+   * Adds services to the Serializer.
+   *
+   * @param \Symfony\Component\DependencyInjection\ContainerBuilder $container
+   *   The container to process.
+   */
+  public function process(ContainerBuilder $container) {
+    $definition = $container->getDefinition('serializer');
+
+    // Retrieve registered Normalizers and Encoders from the container.
+    foreach ($container->findTaggedServiceIds('normalizer') as $id => $attributes) {
+      $priority = isset($attributes[0]['priority']) ? $attributes[0]['priority'] : 0;
+      $normalizers[$priority][] = new Reference($id);
+    }
+    foreach ($container->findTaggedServiceIds('encoder') as $id => $attributes) {
+      $priority = isset($attributes[0]['priority']) ? $attributes[0]['priority'] : 0;
+      $encoders[$priority][] = new Reference($id);
+    }
+
+    // Add the registered Normalizers and Encoders to the Serializer.
+    if (!empty($normalizers)) {
+      $definition->replaceArgument(0, $this->sort($normalizers));
+    }
+    if (!empty($encoders)) {
+      $definition->replaceArgument(1, $this->sort($encoders));
+    }
+
+    // Find all serialization formats known.
+    $formats = array();
+    foreach ($container->findTaggedServiceIds('encoder') as $attributes) {
+      $formats[] = $attributes[0]['format'];
+    }
+    $container->setParameter('serializer.formats', $formats);
+  }
+
+  /**
+   * Sorts by priority.
+   *
+   * Order services from highest priority number to lowest (reverse sorting).
+   *
+   * @param array $services
+   *   A nested array keyed on priority number. For each priority number, the
+   *   value is an array of Symfony\Component\DependencyInjection\Reference
+   *   objects, each a reference to a normalizer or encoder service.
+   *
+   * @return array
+   *   A flattened array of Reference objects from $services, ordered from high
+   *   to low priority.
+   */
+  protected function sort($services) {
+    $sorted = array();
+    krsort($services);
+
+    // Flatten the array.
+    foreach ($services as $a) {
+      $sorted = array_merge($sorted, $a);
+    }
+
+    return $sorted;
+  }
+
+}

core/modules/serialization/src/SerializationServiceProvider.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace Drupal\serialization;
+
+use Drupal\Core\DependencyInjection\ContainerBuilder;
+use Drupal\Core\DependencyInjection\ServiceProviderInterface;
+
+/**
+ * Serialization dependency injection container.
+ */
+class SerializationServiceProvider implements ServiceProviderInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function register(ContainerBuilder $container) {
+    // Add a compiler pass for adding Normalizers and Encoders to Serializer.
+    $container->addCompilerPass(new RegisterSerializationClassesCompilerPass());
+    // Add a compiler pass for adding concrete Resolvers to chain Resolver.
+    $container->addCompilerPass(new RegisterEntityResolversCompilerPass());
+  }
+
+}

core/modules/serialization/src/Tests/EntityResolverTest.php

@@ -0,0 +1,98 @@
+<?php
+
+namespace Drupal\serialization\Tests;
+
+use Drupal\Core\Url;
+use Drupal\entity_test\Entity\EntityTestMulRev;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+
+/**
+ * Tests that entities references can be resolved.
+ *
+ * @group serialization
+ */
+class EntityResolverTest extends NormalizerTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = ['hal', 'rest'];
+
+  /**
+   * The format being tested.
+   *
+   * @var string
+   */
+  protected $format = 'hal_json';
+
+  protected function setUp() {
+    parent::setUp();
+
+    \Drupal::service('router.builder')->rebuild();
+
+    // Create the test field storage.
+    FieldStorageConfig::create(array(
+      'entity_type' => 'entity_test_mulrev',
+      'field_name' => 'field_test_entity_reference',
+      'type' => 'entity_reference',
+      'settings' => array(
+        'target_type' => 'entity_test_mulrev',
+      ),
+    ))->save();
+
+    // Create the test field.
+    FieldConfig::create([
+      'entity_type' => 'entity_test_mulrev',
+      'field_name' => 'field_test_entity_reference',
+      'bundle' => 'entity_test_mulrev',
+    ])->save();
+  }
+
+  /**
+   * Test that fields referencing UUIDs can be denormalized.
+   */
+  function testUuidEntityResolver() {
+    // Create an entity to get the UUID from.
+    $entity = EntityTestMulRev::create(array('type' => 'entity_test_mulrev'));
+    $entity->set('name', 'foobar');
+    $entity->set('field_test_entity_reference', array(array('target_id' => 1)));
+    $entity->save();
+
+    $field_uri = Url::fromUri('base:rest/relation/entity_test_mulrev/entity_test_mulrev/field_test_entity_reference', array('absolute' => TRUE))->toString();
+
+    $data = array(
+      '_links' => array(
+        'type' => array(
+          'href' => Url::fromUri('base:rest/type/entity_test_mulrev/entity_test_mulrev', array('absolute' => TRUE))->toString(),
+        ),
+        $field_uri => array(
+          array(
+            'href' => $entity->url(),
+          ),
+        ),
+      ),
+      '_embedded' => array(
+        $field_uri => array(
+          array(
+            '_links' => array(
+              'self' => $entity->url(),
+            ),
+            'uuid' => array(
+              array(
+                'value' => $entity->uuid(),
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+
+    $denormalized = $this->container->get('serializer')->denormalize($data, 'Drupal\entity_test\Entity\EntityTestMulRev', $this->format);
+    $field_value = $denormalized->get('field_test_entity_reference')->getValue();
+    $this->assertEqual($field_value[0]['target_id'], 1, 'Entity reference resolved using UUID.');
+  }
+
+}

core/modules/serialization/src/Tests/EntitySerializationTest.php

@@ -0,0 +1,226 @@
+<?php
+
+namespace Drupal\serialization\Tests;
+
+use Drupal\Component\Utility\SafeMarkup;
+use Drupal\entity_test\Entity\EntityTestMulRev;
+
+/**
+ * Tests that entities can be serialized to supported core formats.
+ *
+ * @group serialization
+ */
+class EntitySerializationTest extends NormalizerTestBase {
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('serialization', 'system', 'field', 'entity_test', 'text', 'filter', 'user', 'entity_serialization_test');
+
+  /**
+   * The test values.
+   *
+   * @var array
+   */
+  protected $values;
+
+  /**
+   * The test entity.
+   *
+   * @var \Drupal\Core\Entity\ContentEntityBase
+   */
+  protected $entity;
+
+  /**
+   * The test user.
+   *
+   * @var \Drupal\user\Entity\User
+   */
+  protected $user;
+
+  /**
+   * The serializer service.
+   *
+   * @var \Symfony\Component\Serializer\Serializer.
+   */
+  protected $serializer;
+
+  /**
+   * The class name of the test class.
+   *
+   * @var string
+   */
+  protected $entityClass = 'Drupal\entity_test\Entity\EntityTest';
+
+  protected function setUp() {
+    parent::setUp();
+
+    // User create needs sequence table.
+    $this->installSchema('system', array('sequences'));
+
+    // Create a test user to use as the entity owner.
+    $this->user = \Drupal::entityManager()->getStorage('user')->create([
+      'name' => 'serialization_test_user',
+      'mail' => 'foo@example.com',
+      'pass' => '123456',
+    ]);
+    $this->user->save();
+
+    // Create a test entity to serialize.
+    $this->values = array(
+      'name' => $this->randomMachineName(),
+      'user_id' => $this->user->id(),
+      'field_test_text' => array(
+        'value' => $this->randomMachineName(),
+        'format' => 'full_html',
+      ),
+    );
+    $this->entity = EntityTestMulRev::create($this->values);
+    $this->entity->save();
+
+    $this->serializer = $this->container->get('serializer');
+
+    $this->installConfig(array('field'));
+  }
+
+  /**
+   * Test the normalize function.
+   */
+  public function testNormalize() {
+    $expected = array(
+      'id' => array(
+        array('value' => 1),
+      ),
+      'uuid' => array(
+        array('value' => $this->entity->uuid()),
+      ),
+      'langcode' => array(
+        array('value' => 'en'),
+      ),
+      'name' => array(
+        array('value' => $this->values['name']),
+      ),
+      'type' => array(
+        array('value' => 'entity_test_mulrev'),
+      ),
+      'created' => array(
+        array('value' => $this->entity->created->value),
+      ),
+      'user_id' => array(
+        array(
+          'target_id' => $this->user->id(),
+          'target_type' => $this->user->getEntityTypeId(),
+          'target_uuid' => $this->user->uuid(),
+          'url' => $this->user->url(),
+        ),
+      ),
+      'revision_id' => array(
+        array('value' => 1),
+      ),
+      'default_langcode' => array(
+        array('value' => TRUE),
+      ),
+      'non_rev_field' => array(),
+      'field_test_text' => array(
+        array(
+          'value' => $this->values['field_test_text']['value'],
+          'format' => $this->values['field_test_text']['format'],
+        ),
+      ),
+    );
+
+    $normalized = $this->serializer->normalize($this->entity);
+
+    foreach (array_keys($expected) as $fieldName) {
+      $this->assertEqual($expected[$fieldName], $normalized[$fieldName], "ComplexDataNormalizer produces expected array for $fieldName.");
+    }
+    $this->assertEqual(array_diff_key($normalized, $expected), array(), 'No unexpected data is added to the normalized array.');
+  }
+
+  /**
+   * Tests user normalization, using the entity_serialization_test module to
+   * override some default access controls.
+   */
+  public function testUserNormalize() {
+    // Test password isn't available.
+    $normalized = $this->serializer->normalize($this->user);
+
+    $this->assertFalse(array_key_exists('pass', $normalized), '"pass" key does not exist in normalized user');
+    $this->assertFalse(array_key_exists('mail', $normalized), '"mail" key does not exist in normalized user');
+
+    // Test again using our test user, so that our access control override will
+    // allow password viewing.
+    $normalized = $this->serializer->normalize($this->user, NULL, ['account' => $this->user]);
+
+    // The key 'pass' will now exist, but the password value should be
+    // normalized to NULL.
+    $this->assertIdentical($normalized['pass'], [NULL], '"pass" value is normalized to [NULL]');
+  }
+
+  /**
+   * Test registered Serializer's entity serialization for core's formats.
+   */
+  public function testSerialize() {
+    // Test that Serializer responds using the ComplexDataNormalizer and
+    // JsonEncoder. The output of ComplexDataNormalizer::normalize() is tested
+    // elsewhere, so we can just assume that it works properly here.
+    $normalized = $this->serializer->normalize($this->entity, 'json');
+    $expected = json_encode($normalized);
+    // Test 'json'.
+    $actual = $this->serializer->serialize($this->entity, 'json');
+    $this->assertIdentical($actual, $expected, 'Entity serializes to JSON when "json" is requested.');
+    $actual = $this->serializer->serialize($normalized, 'json');
+    $this->assertIdentical($actual, $expected, 'A normalized array serializes to JSON when "json" is requested');
+    // Test 'ajax'.
+    $actual = $this->serializer->serialize($this->entity, 'ajax');
+    $this->assertIdentical($actual, $expected, 'Entity serializes to JSON when "ajax" is requested.');
+    $actual = $this->serializer->serialize($normalized, 'ajax');
+    $this->assertIdentical($actual, $expected, 'A normalized array serializes to JSON when "ajax" is requested');
+
+    // Generate the expected xml in a way that allows changes to entity property
+    // order.
+    $expected = array(
+      'id' => '<id><value>' . $this->entity->id() . '</value></id>',
+      'uuid' => '<uuid><value>' . $this->entity->uuid() . '</value></uuid>',
+      'langcode' => '<langcode><value>en</value></langcode>',
+      'name' => '<name><value>' . $this->values['name'] . '</value></name>',
+      'type' => '<type><value>entity_test_mulrev</value></type>',
+      'created' => '<created><value>' . $this->entity->created->value . '</value></created>',
+      'user_id' => '<user_id><target_id>' . $this->user->id() . '</target_id><target_type>' . $this->user->getEntityTypeId() . '</target_type><target_uuid>' . $this->user->uuid() . '</target_uuid><url>' . $this->user->url() . '</url></user_id>',
+      'revision_id' => '<revision_id><value>' . $this->entity->getRevisionId() . '</value></revision_id>',
+      'default_langcode' => '<default_langcode><value>1</value></default_langcode>',
+      'non_rev_field' => '<non_rev_field/>',
+      'field_test_text' => '<field_test_text><value>' . $this->values['field_test_text']['value'] . '</value><format>' . $this->values['field_test_text']['format'] . '</format></field_test_text>',
+    );
+    // Sort it in the same order as normalised.
+    $expected = array_merge($normalized, $expected);
+    // Add header and footer.
+    array_unshift($expected, '<?xml version="1.0"?>' . PHP_EOL . '<response>');
+    $expected[] = '</response>' . PHP_EOL;
+    // Reduced the array to a string.
+    $expected = implode('', $expected);
+    // Test 'xml'. The output should match that of Symfony's XmlEncoder.
+    $actual = $this->serializer->serialize($this->entity, 'xml');
+    $this->assertIdentical($actual, $expected);
+    $actual = $this->serializer->serialize($normalized, 'xml');
+    $this->assertIdentical($actual, $expected);
+  }
+
+  /**
+   * Tests denormalization of an entity.
+   */
+  public function testDenormalize() {
+    $normalized = $this->serializer->normalize($this->entity);
+
+    foreach (array('json', 'xml') as $type) {
+      $denormalized = $this->serializer->denormalize($normalized, $this->entityClass, $type, array('entity_type' => 'entity_test_mulrev'));
+      $this->assertTrue($denormalized instanceof $this->entityClass, SafeMarkup::format('Denormalized entity is an instance of @class', array('@class' => $this->entityClass)));
+      $this->assertIdentical($denormalized->getEntityTypeId(), $this->entity->getEntityTypeId(), 'Expected entity type found.');
+      $this->assertIdentical($denormalized->bundle(), $this->entity->bundle(), 'Expected entity bundle found.');
+      $this->assertIdentical($denormalized->uuid(), $this->entity->uuid(), 'Expected entity UUID found.');
+    }
+  }
+
+}

core/modules/serialization/src/Tests/NormalizerTestBase.php

@@ -0,0 +1,47 @@
+<?php
+
+namespace Drupal\serialization\Tests;
+
+use Drupal\KernelTests\KernelTestBase;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+
+abstract class NormalizerTestBase extends KernelTestBase {
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = array('serialization', 'system', 'field', 'entity_test', 'text', 'filter', 'user');
+
+  protected function setUp() {
+    parent::setUp();
+
+    $this->installEntitySchema('entity_test_mulrev');
+    $this->installEntitySchema('user');
+    $this->installConfig(array('field'));
+    \Drupal::service('router.builder')->rebuild();
+    \Drupal::moduleHandler()->invoke('rest', 'install');
+
+    // Auto-create a field for testing.
+    FieldStorageConfig::create(array(
+      'entity_type' => 'entity_test_mulrev',
+      'field_name' => 'field_test_text',
+      'type' => 'text',
+      'cardinality' => 1,
+      'translatable' => FALSE,
+    ))->save();
+    FieldConfig::create(array(
+      'entity_type' => 'entity_test_mulrev',
+      'field_name' => 'field_test_text',
+      'bundle' => 'entity_test_mulrev',
+      'label' => 'Test text-field',
+      'widget' => array(
+        'type' => 'text_textfield',
+        'weight' => 0,
+      ),
+    ))->save();
+  }
+
+}