Move into nested docroot

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

@@ -0,0 +1,35 @@
+<?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);
+  }
+
+}

web/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);
+  }
+
+}

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

@@ -0,0 +1,48 @@
+<?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;
+      }
+    }
+  }
+
+}

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

@@ -0,0 +1,18 @@
+<?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);
+
+}

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

@@ -0,0 +1,38 @@
+<?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);
+
+}

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

@@ -0,0 +1,22 @@
+<?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;
+  }
+
+}

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

@@ -0,0 +1,23 @@
+<?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);
+
+}

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

@@ -0,0 +1,45 @@
+<?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;
+  }
+
+}

web/core/modules/serialization/src/EventSubscriber/DefaultExceptionSubscriber.php

@@ -0,0 +1,144 @@
+<?php
+
+namespace Drupal\serialization\EventSubscriber;
+
+use Drupal\Core\EventSubscriber\HttpExceptionSubscriberBase;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent;
+use Symfony\Component\Serializer\SerializerInterface;
+
+/**
+ * Handles default error responses in serialization formats.
+ */
+class DefaultExceptionSubscriber extends HttpExceptionSubscriberBase {
+
+  /**
+   * The serializer.
+   *
+   * @var \Symfony\Component\Serializer\Serializer
+   */
+  protected $serializer;
+
+  /**
+   * The available serialization formats.
+   *
+   * @var array
+   */
+  protected $serializerFormats = [];
+
+  /**
+   * DefaultExceptionSubscriber constructor.
+   *
+   * @param \Symfony\Component\Serializer\SerializerInterface $serializer
+   *   The serializer service.
+   * @param array $serializer_formats
+   *   The available serialization formats.
+   */
+  public function __construct(SerializerInterface $serializer, array $serializer_formats) {
+    $this->serializer = $serializer;
+    $this->serializerFormats = $serializer_formats;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getHandledFormats() {
+    return $this->serializerFormats;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static function getPriority() {
+    // This will fire after the most common HTML handler, since HTML requests
+    // are still more common than HTTP requests.
+    return -75;
+  }
+
+  /**
+   * Handles a 400 error for HTTP.
+   *
+   * @param \Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent $event
+   *   The event to process.
+   */
+  public function on400(GetResponseForExceptionEvent $event) {
+    $this->setEventResponse($event, Response::HTTP_BAD_REQUEST);
+  }
+
+  /**
+   * Handles a 403 error for HTTP.
+   *
+   * @param \Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent $event
+   *   The event to process.
+   */
+  public function on403(GetResponseForExceptionEvent $event) {
+    $this->setEventResponse($event, Response::HTTP_FORBIDDEN);
+  }
+
+  /**
+   * Handles a 404 error for HTTP.
+   *
+   * @param \Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent $event
+   *   The event to process.
+   */
+  public function on404(GetResponseForExceptionEvent $event) {
+    $this->setEventResponse($event, Response::HTTP_NOT_FOUND);
+  }
+
+  /**
+   * Handles a 405 error for HTTP.
+   *
+   * @param \Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent $event
+   *   The event to process.
+   */
+  public function on405(GetResponseForExceptionEvent $event) {
+    $this->setEventResponse($event, Response::HTTP_METHOD_NOT_ALLOWED);
+  }
+
+  /**
+   * Handles a 406 error for HTTP.
+   *
+   * @param \Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent $event
+   *   The event to process.
+   */
+  public function on406(GetResponseForExceptionEvent $event) {
+    $this->setEventResponse($event, Response::HTTP_NOT_ACCEPTABLE);
+  }
+
+  /**
+   * Handles a 422 error for HTTP.
+   *
+   * @param \Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent $event
+   *   The event to process.
+   */
+  public function on422(GetResponseForExceptionEvent $event) {
+    $this->setEventResponse($event, Response::HTTP_UNPROCESSABLE_ENTITY);
+  }
+
+  /**
+   * Handles a 429 error for HTTP.
+   *
+   * @param \Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent $event
+   *   The event to process.
+   */
+  public function on429(GetResponseForExceptionEvent $event) {
+    $this->setEventResponse($event, Response::HTTP_TOO_MANY_REQUESTS);
+  }
+
+  /**
+   * Sets the Response for the exception event.
+   *
+   * @param \Symfony\Component\HttpKernel\Event\GetResponseForExceptionEvent $event
+   *   The current exception event.
+   * @param int $status
+   *   The HTTP status code to set for the response.
+   */
+  protected function setEventResponse(GetResponseForExceptionEvent $event, $status) {
+    $format = $event->getRequest()->getRequestFormat();
+    $content = ['message' => $event->getException()->getMessage()];
+    $encoded_content = $this->serializer->serialize($content, $format);
+    $response = new Response($encoded_content, $status);
+    $event->setResponse($response);
+  }
+
+}

web/core/modules/serialization/src/EventSubscriber/UserRouteAlterSubscriber.php

@@ -0,0 +1,72 @@
+<?php
+
+namespace Drupal\serialization\EventSubscriber;
+
+use Drupal\Core\Routing\RouteBuildEvent;
+use Drupal\Core\Routing\RoutingEvents;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\Serializer\SerializerInterface;
+
+/**
+ * Alters user authentication routes to support additional serialization formats.
+ */
+class UserRouteAlterSubscriber implements EventSubscriberInterface {
+
+  /**
+   * The serializer.
+   *
+   * @var \Symfony\Component\Serializer\Serializer
+   */
+  protected $serializer;
+
+  /**
+   * The available serialization formats.
+   *
+   * @var array
+   */
+  protected $serializerFormats = [];
+
+  /**
+   * UserRouteAlterSubscriber constructor.
+   *
+   * @param \Symfony\Component\Serializer\SerializerInterface $serializer
+   *   The serializer service.
+   * @param array $serializer_formats
+   *   The available serializer formats.
+   */
+  public function __construct(SerializerInterface $serializer, array $serializer_formats) {
+    $this->serializer = $serializer;
+    $this->serializerFormats = $serializer_formats;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getSubscribedEvents() {
+    $events[RoutingEvents::ALTER][] = 'onRoutingAlterAddFormats';
+    return $events;
+  }
+
+  /**
+   * Adds supported formats to the user authentication HTTP routes.
+   *
+   * @param \Drupal\Core\Routing\RouteBuildEvent $event
+   *   The event to process.
+   */
+  public function onRoutingAlterAddFormats(RouteBuildEvent $event) {
+    $route_names = [
+      'user.login_status.http',
+      'user.login.http',
+      'user.logout.http',
+    ];
+    $routes = $event->getRouteCollection();
+    foreach ($route_names as $route_name) {
+      if ($route = $routes->get($route_name)) {
+        $formats = explode('|', $route->getRequirement('_format'));
+        $formats = array_unique(array_merge($formats, $this->serializerFormats));
+        $route->setRequirement('_format', implode('|', $formats));
+      }
+    }
+  }
+
+}

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

@@ -0,0 +1,35 @@
+<?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;
+  }
+
+}

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

@@ -0,0 +1,24 @@
+<?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();
+  }
+
+}

web/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;
+  }
+
+}

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

@@ -0,0 +1,92 @@
+<?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;
+  }
+
+}

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

@@ -0,0 +1,42 @@
+<?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;
+  }
+
+}

web/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, $context);
+    }
+    return $attributes;
+  }
+
+}

web/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;
+  }
+
+}

web/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);
+  }
+
+}

web/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;
+  }
+
+}

web/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();
+  }
+
+}

web/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;
+  }
+
+}

web/core/modules/serialization/src/RegisterSerializationClassesCompilerPass.php

@@ -0,0 +1,82 @@
+<?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();
+    $format_providers = [];
+    foreach ($container->findTaggedServiceIds('encoder') as $service_id => $attributes) {
+      $format = $attributes[0]['format'];
+      $formats[] = $format;
+
+      if ($provider_tag = $container->getDefinition($service_id)->getTag('_provider')) {
+        $format_providers[$format] = $provider_tag[0]['provider'];
+      }
+    }
+    $container->setParameter('serializer.formats', $formats);
+    $container->setParameter('serializer.format_providers', $format_providers);
+  }
+
+  /**
+   * 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;
+  }
+
+}

web/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());
+  }
+
+}

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

@@ -0,0 +1,13 @@
+<?php
+
+namespace Drupal\serialization\Tests;
+
+use Drupal\Tests\serialization\Kernel\NormalizerTestBase as SerializationNormalizerTestBase;
+
+/**
+ * Helper base class to set up some test fields for serialization testing.
+ *
+ * @deprecated Scheduled for removal in Drupal 9.0.0.
+ *   Use \Drupal\Tests\serialization\Kernel\NormalizerTestBase instead.
+ */
+abstract class NormalizerTestBase extends SerializationNormalizerTestBase { }

web/core/modules/serialization/src/Tests/RegisterSerializationClassesCompilerPassTest.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace Drupal\serialization\Tests;
+
+use Drupal\Core\DependencyInjection\ContainerBuilder;
+use Drupal\serialization\RegisterSerializationClassesCompilerPass;
+use Symfony\Component\DependencyInjection\Definition;
+use Symfony\Component\Serializer\Serializer;
+
+/**
+ * @coversDefaultClass \Drupal\serialization\RegisterSerializationClassesCompilerPass
+ * @group serialization
+ */
+class RegisterSerializationClassesCompilerPassTest extends \PHPUnit_Framework_TestCase {
+
+  /**
+   * @covers ::process
+   */
+  public function testEncoders() {
+    $container = new ContainerBuilder();
+    $container->setDefinition('serializer', new Definition(Serializer::class, [[], []]));
+
+    $definition = new Definition('TestClass');
+    $definition->addTag('encoder', ['format' => 'xml']);
+    $definition->addTag('_provider', ['provider' => 'test_provider_a']);
+    $container->setDefinition('encoder_1', $definition);
+
+    $definition = new Definition('TestClass');
+    $definition->addTag('encoder', ['format' => 'json']);
+    $definition->addTag('_provider', ['provider' => 'test_provider_a']);
+    $container->setDefinition('encoder_2', $definition);
+
+    $definition = new Definition('TestClass');
+    $definition->addTag('encoder', ['format' => 'hal_json']);
+    $definition->addTag('_provider', ['provider' => 'test_provider_b']);
+    $container->setDefinition('encoder_3', $definition);
+
+    $compiler_pass = new RegisterSerializationClassesCompilerPass();
+    $compiler_pass->process($container);
+
+    $this->assertEquals(['xml', 'json', 'hal_json'], $container->getParameter('serializer.formats'));
+    $this->assertEquals(['xml' => 'test_provider_a', 'json' => 'test_provider_a', 'hal_json' => 'test_provider_b'], $container->getParameter('serializer.format_providers'));
+  }
+
+}