Update to drupal 8.0.0-rc1. For more information, see https://www.drupal.org/node/2582663

vendor/symfony/serializer/Encoder/ChainDecoder.php

@@ -0,0 +1,82 @@
+<?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\Encoder;
+
+use Symfony\Component\Serializer\Exception\RuntimeException;
+
+/**
+ * Decoder delegating the decoding to a chain of decoders.
+ *
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ * @author Lukas Kahwe Smith <smith@pooteeweet.org>
+ */
+class ChainDecoder implements DecoderInterface
+{
+    protected $decoders = array();
+    protected $decoderByFormat = array();
+
+    public function __construct(array $decoders = array())
+    {
+        $this->decoders = $decoders;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    final public function decode($data, $format, array $context = array())
+    {
+        return $this->getDecoder($format)->decode($data, $format, $context);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function supportsDecoding($format)
+    {
+        try {
+            $this->getDecoder($format);
+        } catch (RuntimeException $e) {
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Gets the decoder supporting the format.
+     *
+     * @param string $format
+     *
+     * @return DecoderInterface
+     *
+     * @throws RuntimeException if no decoder is found
+     */
+    private function getDecoder($format)
+    {
+        if (isset($this->decoderByFormat[$format])
+            && isset($this->decoders[$this->decoderByFormat[$format]])
+        ) {
+            return $this->decoders[$this->decoderByFormat[$format]];
+        }
+
+        foreach ($this->decoders as $i => $decoder) {
+            if ($decoder->supportsDecoding($format)) {
+                $this->decoderByFormat[$format] = $i;
+
+                return $decoder;
+            }
+        }
+
+        throw new RuntimeException(sprintf('No decoder found for format "%s".', $format));
+    }
+}

vendor/symfony/serializer/Encoder/ChainEncoder.php

@@ -0,0 +1,104 @@
+<?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\Encoder;
+
+use Symfony\Component\Serializer\Exception\RuntimeException;
+
+/**
+ * Encoder delegating the decoding to a chain of encoders.
+ *
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ * @author Lukas Kahwe Smith <smith@pooteeweet.org>
+ */
+class ChainEncoder implements EncoderInterface
+{
+    protected $encoders = array();
+    protected $encoderByFormat = array();
+
+    public function __construct(array $encoders = array())
+    {
+        $this->encoders = $encoders;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    final public function encode($data, $format, array $context = array())
+    {
+        return $this->getEncoder($format)->encode($data, $format, $context);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function supportsEncoding($format)
+    {
+        try {
+            $this->getEncoder($format);
+        } catch (RuntimeException $e) {
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Checks whether the normalization is needed for the given format.
+     *
+     * @param string $format
+     *
+     * @return bool
+     */
+    public function needsNormalization($format)
+    {
+        $encoder = $this->getEncoder($format);
+
+        if (!$encoder instanceof NormalizationAwareInterface) {
+            return true;
+        }
+
+        if ($encoder instanceof self) {
+            return $encoder->needsNormalization($format);
+        }
+
+        return false;
+    }
+
+    /**
+     * Gets the encoder supporting the format.
+     *
+     * @param string $format
+     *
+     * @return EncoderInterface
+     *
+     * @throws RuntimeException if no encoder is found
+     */
+    private function getEncoder($format)
+    {
+        if (isset($this->encoderByFormat[$format])
+            && isset($this->encoders[$this->encoderByFormat[$format]])
+        ) {
+            return $this->encoders[$this->encoderByFormat[$format]];
+        }
+
+        foreach ($this->encoders as $i => $encoder) {
+            if ($encoder->supportsEncoding($format)) {
+                $this->encoderByFormat[$format] = $i;
+
+                return $encoder;
+            }
+        }
+
+        throw new RuntimeException(sprintf('No encoder found for format "%s".', $format));
+    }
+}

vendor/symfony/serializer/Encoder/DecoderInterface.php

@@ -0,0 +1,49 @@
+<?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\Encoder;
+
+use Symfony\Component\Serializer\Exception\UnexpectedValueException;
+
+/**
+ * Defines the interface of decoders.
+ *
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ */
+interface DecoderInterface
+{
+    /**
+     * Decodes a string into PHP data.
+     *
+     * @param string $data    Data to decode
+     * @param string $format  Format name
+     * @param array  $context options that decoders have access to.
+     *
+     * The format parameter specifies which format the data is in; valid values
+     * depend on the specific implementation. Authors implementing this interface
+     * are encouraged to document which formats they support in a non-inherited
+     * phpdoc comment.
+     *
+     * @return mixed
+     *
+     * @throws UnexpectedValueException
+     */
+    public function decode($data, $format, array $context = array());
+
+    /**
+     * Checks whether the deserializer can decode from given format.
+     *
+     * @param string $format format name
+     *
+     * @return bool
+     */
+    public function supportsDecoding($format);
+}

vendor/symfony/serializer/Encoder/EncoderInterface.php

@@ -0,0 +1,44 @@
+<?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\Encoder;
+
+use Symfony\Component\Serializer\Exception\UnexpectedValueException;
+
+/**
+ * Defines the interface of encoders.
+ *
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ */
+interface EncoderInterface
+{
+    /**
+     * Encodes data into the given format.
+     *
+     * @param mixed  $data    Data to encode
+     * @param string $format  Format name
+     * @param array  $context options that normalizers/encoders have access to.
+     *
+     * @return scalar
+     *
+     * @throws UnexpectedValueException
+     */
+    public function encode($data, $format, array $context = array());
+
+    /**
+     * Checks whether the serializer can encode to given format.
+     *
+     * @param string $format format name
+     *
+     * @return bool
+     */
+    public function supportsEncoding($format);
+}

vendor/symfony/serializer/Encoder/JsonDecode.php

@@ -0,0 +1,142 @@
+<?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\Encoder;
+
+use Symfony\Component\Serializer\Exception\UnexpectedValueException;
+
+/**
+ * Decodes JSON data.
+ *
+ * @author Sander Coolen <sander@jibber.nl>
+ */
+class JsonDecode implements DecoderInterface
+{
+    /**
+     * Specifies if the returned result should be an associative array or a nested stdClass object hierarchy.
+     *
+     * @var bool
+     */
+    private $associative;
+
+    /**
+     * Specifies the recursion depth.
+     *
+     * @var int
+     */
+    private $recursionDepth;
+
+    private $lastError = JSON_ERROR_NONE;
+
+    protected $serializer;
+
+    /**
+     * Constructs a new JsonDecode instance.
+     *
+     * @param bool $associative True to return the result associative array, false for a nested stdClass hierarchy
+     * @param int  $depth       Specifies the recursion depth
+     */
+    public function __construct($associative = false, $depth = 512)
+    {
+        $this->associative = $associative;
+        $this->recursionDepth = (int) $depth;
+    }
+
+    /**
+     * Returns the last decoding error (if any).
+     *
+     * @return int
+     *
+     * @deprecated since version 2.5, to be removed in 3.0.
+     *             The {@self decode()} method throws an exception if error found.
+     * @see http://php.net/manual/en/function.json-last-error.php json_last_error
+     */
+    public function getLastError()
+    {
+        @trigger_error('The '.__METHOD__.' method is deprecated since version 2.5 and will be removed in 3.0. Catch the exception raised by the decode() method instead to get the last JSON decoding error.', E_USER_DEPRECATED);
+
+        return $this->lastError;
+    }
+
+    /**
+     * Decodes data.
+     *
+     * @param string $data    The encoded JSON string to decode
+     * @param string $format  Must be set to JsonEncoder::FORMAT
+     * @param array  $context An optional set of options for the JSON decoder; see below
+     *
+     * The $context array is a simple key=>value array, with the following supported keys:
+     *
+     * json_decode_associative: boolean
+     *      If true, returns the object as associative array.
+     *      If false, returns the object as nested stdClass
+     *      If not specified, this method will use the default set in JsonDecode::__construct
+     *
+     * json_decode_recursion_depth: integer
+     *      Specifies the maximum recursion depth
+     *      If not specified, this method will use the default set in JsonDecode::__construct
+     *
+     * json_decode_options: integer
+     *      Specifies additional options as per documentation for json_decode. Only supported with PHP 5.4.0 and higher
+     *
+     * @return mixed
+     *
+     * @throws UnexpectedValueException
+     *
+     * @see http://php.net/json_decode json_decode
+     */
+    public function decode($data, $format, array $context = array())
+    {
+        $context = $this->resolveContext($context);
+
+        $associative = $context['json_decode_associative'];
+        $recursionDepth = $context['json_decode_recursion_depth'];
+        $options = $context['json_decode_options'];
+
+        if (PHP_VERSION_ID >= 50400) {
+            $decodedData = json_decode($data, $associative, $recursionDepth, $options);
+        } else {
+            $decodedData = json_decode($data, $associative, $recursionDepth);
+        }
+
+        if (JSON_ERROR_NONE !== $this->lastError = json_last_error()) {
+            throw new UnexpectedValueException(JsonEncoder::getLastErrorMessage());
+        }
+
+        return $decodedData;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function supportsDecoding($format)
+    {
+        return JsonEncoder::FORMAT === $format;
+    }
+
+    /**
+     * Merges the default options of the Json Decoder with the passed context.
+     *
+     * @param array $context
+     *
+     * @return array
+     */
+    private function resolveContext(array $context)
+    {
+        $defaultOptions = array(
+            'json_decode_associative' => $this->associative,
+            'json_decode_recursion_depth' => $this->recursionDepth,
+            'json_decode_options' => 0,
+        );
+
+        return array_merge($defaultOptions, $context);
+    }
+}

vendor/symfony/serializer/Encoder/JsonEncode.php

@@ -0,0 +1,84 @@
+<?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\Encoder;
+
+use Symfony\Component\Serializer\Exception\UnexpectedValueException;
+
+/**
+ * Encodes JSON data.
+ *
+ * @author Sander Coolen <sander@jibber.nl>
+ */
+class JsonEncode implements EncoderInterface
+{
+    private $options;
+    private $lastError = JSON_ERROR_NONE;
+
+    public function __construct($bitmask = 0)
+    {
+        $this->options = $bitmask;
+    }
+
+    /**
+     * Returns the last encoding error (if any).
+     *
+     * @return int
+     *
+     * @deprecated since version 2.5, to be removed in 3.0.
+     *             The {@self encode()} throws an exception if error found.
+     * @see http://php.net/manual/en/function.json-last-error.php json_last_error
+     */
+    public function getLastError()
+    {
+        @trigger_error('The '.__METHOD__.' method is deprecated since version 2.5 and will be removed in 3.0. Catch the exception raised by the encode() method instead to get the last JSON encoding error.', E_USER_DEPRECATED);
+
+        return $this->lastError;
+    }
+
+    /**
+     * Encodes PHP data to a JSON string.
+     *
+     * {@inheritdoc}
+     */
+    public function encode($data, $format, array $context = array())
+    {
+        $context = $this->resolveContext($context);
+
+        $encodedJson = json_encode($data, $context['json_encode_options']);
+
+        if (JSON_ERROR_NONE !== $this->lastError = json_last_error()) {
+            throw new UnexpectedValueException(JsonEncoder::getLastErrorMessage());
+        }
+
+        return $encodedJson;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function supportsEncoding($format)
+    {
+        return JsonEncoder::FORMAT === $format;
+    }
+
+    /**
+     * Merge default json encode options with context.
+     *
+     * @param array $context
+     *
+     * @return array
+     */
+    private function resolveContext(array $context = array())
+    {
+        return array_merge(array('json_encode_options' => $this->options), $context);
+    }
+}

vendor/symfony/serializer/Encoder/JsonEncoder.php

@@ -0,0 +1,125 @@
+<?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\Encoder;
+
+/**
+ * Encodes JSON data.
+ *
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ */
+class JsonEncoder implements EncoderInterface, DecoderInterface
+{
+    const FORMAT = 'json';
+
+    /**
+     * @var JsonEncode
+     */
+    protected $encodingImpl;
+
+    /**
+     * @var JsonDecode
+     */
+    protected $decodingImpl;
+
+    public function __construct(JsonEncode $encodingImpl = null, JsonDecode $decodingImpl = null)
+    {
+        $this->encodingImpl = $encodingImpl ?: new JsonEncode();
+        $this->decodingImpl = $decodingImpl ?: new JsonDecode(true);
+    }
+
+    /**
+     * Returns the last encoding error (if any).
+     *
+     * @return int
+     *
+     * @deprecated since version 2.5, to be removed in 3.0. JsonEncode throws exception if an error is found.
+     */
+    public function getLastEncodingError()
+    {
+        @trigger_error('The '.__METHOD__.' method is deprecated since version 2.5 and will be removed in 3.0. Catch the exception raised by the Symfony\Component\Serializer\Encoder\JsonEncode::encode() method instead to get the last JSON encoding error.', E_USER_DEPRECATED);
+
+        return $this->encodingImpl->getLastError();
+    }
+
+    /**
+     * Returns the last decoding error (if any).
+     *
+     * @return int
+     *
+     * @deprecated since version 2.5, to be removed in 3.0. JsonDecode throws exception if an error is found.
+     */
+    public function getLastDecodingError()
+    {
+        @trigger_error('The '.__METHOD__.' method is deprecated since version 2.5 and will be removed in 3.0. Catch the exception raised by the Symfony\Component\Serializer\Encoder\JsonDecode::decode() method instead to get the last JSON decoding error.', E_USER_DEPRECATED);
+
+        return $this->decodingImpl->getLastError();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function encode($data, $format, array $context = array())
+    {
+        return $this->encodingImpl->encode($data, self::FORMAT, $context);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function decode($data, $format, array $context = array())
+    {
+        return $this->decodingImpl->decode($data, self::FORMAT, $context);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function supportsEncoding($format)
+    {
+        return self::FORMAT === $format;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function supportsDecoding($format)
+    {
+        return self::FORMAT === $format;
+    }
+
+    /**
+     * Resolves json_last_error message.
+     *
+     * @return string
+     */
+    public static function getLastErrorMessage()
+    {
+        if (function_exists('json_last_error_msg')) {
+            return json_last_error_msg();
+        }
+
+        switch (json_last_error()) {
+            case JSON_ERROR_DEPTH:
+                return 'Maximum stack depth exceeded';
+            case JSON_ERROR_STATE_MISMATCH:
+                return 'Underflow or the modes mismatch';
+            case JSON_ERROR_CTRL_CHAR:
+                return 'Unexpected control character found';
+            case JSON_ERROR_SYNTAX:
+                return 'Syntax error, malformed JSON';
+            case JSON_ERROR_UTF8:
+                return 'Malformed UTF-8 characters, possibly incorrectly encoded';
+            default:
+                return 'Unknown error';
+        }
+    }
+}

vendor/symfony/serializer/Encoder/NormalizationAwareInterface.php

@@ -0,0 +1,24 @@
+<?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\Encoder;
+
+/**
+ * Defines the interface of encoders that will normalize data themselves.
+ *
+ * Implementing this interface essentially just tells the Serializer that the
+ * data should not be pre-normalized before being passed to this Encoder.
+ *
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ */
+interface NormalizationAwareInterface
+{
+}

vendor/symfony/serializer/Encoder/SerializerAwareEncoder.php

@@ -0,0 +1,33 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Serializer\Encoder;
+
+use Symfony\Component\Serializer\SerializerInterface;
+use Symfony\Component\Serializer\SerializerAwareInterface;
+
+/**
+ * SerializerAware Encoder implementation.
+ *
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ */
+abstract class SerializerAwareEncoder implements SerializerAwareInterface
+{
+    protected $serializer;
+
+    /**
+     * {@inheritdoc}
+     */
+    public function setSerializer(SerializerInterface $serializer)
+    {
+        $this->serializer = $serializer;
+    }
+}

vendor/symfony/serializer/Encoder/XmlEncoder.php

@@ -0,0 +1,536 @@
+<?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\Encoder;
+
+use Symfony\Component\Serializer\Exception\UnexpectedValueException;
+
+/**
+ * Encodes XML data.
+ *
+ * @author Jordi Boggiano <j.boggiano@seld.be>
+ * @author John Wards <jwards@whiteoctober.co.uk>
+ * @author Fabian Vogler <fabian@equivalence.ch>
+ * @author Kévin Dunglas <dunglas@gmail.com>
+ */
+class XmlEncoder extends SerializerAwareEncoder implements EncoderInterface, DecoderInterface, NormalizationAwareInterface
+{
+    /**
+     * @var \DOMDocument
+     */
+    private $dom;
+    private $format;
+    private $context;
+    private $rootNodeName = 'response';
+
+    /**
+     * Construct new XmlEncoder and allow to change the root node element name.
+     *
+     * @param string $rootNodeName
+     */
+    public function __construct($rootNodeName = 'response')
+    {
+        $this->rootNodeName = $rootNodeName;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function encode($data, $format, array $context = array())
+    {
+        if ($data instanceof \DOMDocument) {
+            return $data->saveXML();
+        }
+
+        $xmlRootNodeName = $this->resolveXmlRootName($context);
+
+        $this->dom = $this->createDomDocument($context);
+        $this->format = $format;
+        $this->context = $context;
+
+        if (null !== $data && !is_scalar($data)) {
+            $root = $this->dom->createElement($xmlRootNodeName);
+            $this->dom->appendChild($root);
+            $this->buildXml($root, $data, $xmlRootNodeName);
+        } else {
+            $this->appendNode($this->dom, $data, $xmlRootNodeName);
+        }
+
+        return $this->dom->saveXML();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function decode($data, $format, array $context = array())
+    {
+        if ('' === trim($data)) {
+            throw new UnexpectedValueException('Invalid XML data, it can not be empty.');
+        }
+
+        $internalErrors = libxml_use_internal_errors(true);
+        $disableEntities = libxml_disable_entity_loader(true);
+        libxml_clear_errors();
+
+        $dom = new \DOMDocument();
+        $dom->loadXML($data, LIBXML_NONET | LIBXML_NOBLANKS);
+
+        libxml_use_internal_errors($internalErrors);
+        libxml_disable_entity_loader($disableEntities);
+
+        if ($error = libxml_get_last_error()) {
+            libxml_clear_errors();
+
+            throw new UnexpectedValueException($error->message);
+        }
+
+        foreach ($dom->childNodes as $child) {
+            if ($child->nodeType === XML_DOCUMENT_TYPE_NODE) {
+                throw new UnexpectedValueException('Document types are not allowed.');
+            }
+        }
+
+        $rootNode = $dom->firstChild;
+
+        // todo: throw an exception if the root node name is not correctly configured (bc)
+
+        if ($rootNode->hasChildNodes()) {
+            $xpath = new \DOMXPath($dom);
+            $data = array();
+            foreach ($xpath->query('namespace::*', $dom->documentElement) as $nsNode) {
+                $data['@'.$nsNode->nodeName] = $nsNode->nodeValue;
+            }
+
+            unset($data['@xmlns:xml']);
+
+            if (empty($data)) {
+                return $this->parseXml($rootNode);
+            }
+
+            return array_merge($data, (array) $this->parseXml($rootNode));
+        }
+
+        if (!$rootNode->hasAttributes()) {
+            return $rootNode->nodeValue;
+        }
+
+        $data = array();
+
+        foreach ($rootNode->attributes as $attrKey => $attr) {
+            $data['@'.$attrKey] = $attr->nodeValue;
+        }
+
+        $data['#'] = $rootNode->nodeValue;
+
+        return $data;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function supportsEncoding($format)
+    {
+        return 'xml' === $format;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function supportsDecoding($format)
+    {
+        return 'xml' === $format;
+    }
+
+    /**
+     * Sets the root node name.
+     *
+     * @param string $name root node name
+     */
+    public function setRootNodeName($name)
+    {
+        $this->rootNodeName = $name;
+    }
+
+    /**
+     * Returns the root node name.
+     *
+     * @return string
+     */
+    public function getRootNodeName()
+    {
+        return $this->rootNodeName;
+    }
+
+    /**
+     * @param \DOMNode $node
+     * @param string   $val
+     *
+     * @return bool
+     */
+    final protected function appendXMLString(\DOMNode $node, $val)
+    {
+        if (strlen($val) > 0) {
+            $frag = $this->dom->createDocumentFragment();
+            $frag->appendXML($val);
+            $node->appendChild($frag);
+
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * @param \DOMNode $node
+     * @param string   $val
+     *
+     * @return bool
+     */
+    final protected function appendText(\DOMNode $node, $val)
+    {
+        $nodeText = $this->dom->createTextNode($val);
+        $node->appendChild($nodeText);
+
+        return true;
+    }
+
+    /**
+     * @param \DOMNode $node
+     * @param string   $val
+     *
+     * @return bool
+     */
+    final protected function appendCData(\DOMNode $node, $val)
+    {
+        $nodeText = $this->dom->createCDATASection($val);
+        $node->appendChild($nodeText);
+
+        return true;
+    }
+
+    /**
+     * @param \DOMNode             $node
+     * @param \DOMDocumentFragment $fragment
+     *
+     * @return bool
+     */
+    final protected function appendDocumentFragment(\DOMNode $node, $fragment)
+    {
+        if ($fragment instanceof \DOMDocumentFragment) {
+            $node->appendChild($fragment);
+
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Checks the name is a valid xml element name.
+     *
+     * @param string $name
+     *
+     * @return bool
+     */
+    final protected function isElementNameValid($name)
+    {
+        return $name &&
+            false === strpos($name, ' ') &&
+            preg_match('#^[\pL_][\pL0-9._:-]*$#ui', $name);
+    }
+
+    /**
+     * Parse the input DOMNode into an array or a string.
+     *
+     * @param \DOMNode $node xml to parse
+     *
+     * @return array|string
+     */
+    private function parseXml(\DOMNode $node)
+    {
+        $data = $this->parseXmlAttributes($node);
+
+        $value = $this->parseXmlValue($node);
+
+        if (!count($data)) {
+            return $value;
+        }
+
+        if (!is_array($value)) {
+            $data['#'] = $value;
+
+            return $data;
+        }
+
+        if (1 === count($value) && key($value)) {
+            $data[key($value)] = current($value);
+
+            return $data;
+        }
+
+        foreach ($value as $key => $val) {
+            $data[$key] = $val;
+        }
+
+        return $data;
+    }
+
+    /**
+     * Parse the input DOMNode attributes into an array.
+     *
+     * @param \DOMNode $node xml to parse
+     *
+     * @return array
+     */
+    private function parseXmlAttributes(\DOMNode $node)
+    {
+        if (!$node->hasAttributes()) {
+            return array();
+        }
+
+        $data = array();
+
+        foreach ($node->attributes as $attr) {
+            if (ctype_digit($attr->nodeValue)) {
+                $data['@'.$attr->nodeName] = (int) $attr->nodeValue;
+            } else {
+                $data['@'.$attr->nodeName] = $attr->nodeValue;
+            }
+        }
+
+        return $data;
+    }
+
+    /**
+     * Parse the input DOMNode value (content and children) into an array or a string.
+     *
+     * @param \DOMNode $node xml to parse
+     *
+     * @return array|string
+     */
+    private function parseXmlValue(\DOMNode $node)
+    {
+        if (!$node->hasChildNodes()) {
+            return $node->nodeValue;
+        }
+
+        if (1 === $node->childNodes->length && in_array($node->firstChild->nodeType, array(XML_TEXT_NODE, XML_CDATA_SECTION_NODE))) {
+            return $node->firstChild->nodeValue;
+        }
+
+        $value = array();
+
+        foreach ($node->childNodes as $subnode) {
+            $val = $this->parseXml($subnode);
+
+            if ('item' === $subnode->nodeName && isset($val['@key'])) {
+                if (isset($val['#'])) {
+                    $value[$val['@key']] = $val['#'];
+                } else {
+                    $value[$val['@key']] = $val;
+                }
+            } else {
+                $value[$subnode->nodeName][] = $val;
+            }
+        }
+
+        foreach ($value as $key => $val) {
+            if (is_array($val) && 1 === count($val)) {
+                $value[$key] = current($val);
+            }
+        }
+
+        return $value;
+    }
+
+    /**
+     * Parse the data and convert it to DOMElements.
+     *
+     * @param \DOMNode     $parentNode
+     * @param array|object $data
+     * @param string|null  $xmlRootNodeName
+     *
+     * @return bool
+     *
+     * @throws UnexpectedValueException
+     */
+    private function buildXml(\DOMNode $parentNode, $data, $xmlRootNodeName = null)
+    {
+        $append = true;
+
+        if (is_array($data) || $data instanceof \Traversable) {
+            foreach ($data as $key => $data) {
+                //Ah this is the magic @ attribute types.
+                if (0 === strpos($key, '@') && is_scalar($data) && $this->isElementNameValid($attributeName = substr($key, 1))) {
+                    $parentNode->setAttribute($attributeName, $data);
+                } elseif ($key === '#') {
+                    $append = $this->selectNodeType($parentNode, $data);
+                } elseif (is_array($data) && false === is_numeric($key)) {
+                    // Is this array fully numeric keys?
+                    if (ctype_digit(implode('', array_keys($data)))) {
+                        /*
+                         * Create nodes to append to $parentNode based on the $key of this array
+                         * Produces <xml><item>0</item><item>1</item></xml>
+                         * From array("item" => array(0,1));.
+                         */
+                        foreach ($data as $subData) {
+                            $append = $this->appendNode($parentNode, $subData, $key);
+                        }
+                    } else {
+                        $append = $this->appendNode($parentNode, $data, $key);
+                    }
+                } elseif (is_numeric($key) || !$this->isElementNameValid($key)) {
+                    $append = $this->appendNode($parentNode, $data, 'item', $key);
+                } else {
+                    $append = $this->appendNode($parentNode, $data, $key);
+                }
+            }
+
+            return $append;
+        }
+
+        if (is_object($data)) {
+            $data = $this->serializer->normalize($data, $this->format, $this->context);
+            if (null !== $data && !is_scalar($data)) {
+                return $this->buildXml($parentNode, $data, $xmlRootNodeName);
+            }
+
+            // top level data object was normalized into a scalar
+            if (!$parentNode->parentNode->parentNode) {
+                $root = $parentNode->parentNode;
+                $root->removeChild($parentNode);
+
+                return $this->appendNode($root, $data, $xmlRootNodeName);
+            }
+
+            return $this->appendNode($parentNode, $data, 'data');
+        }
+
+        throw new UnexpectedValueException(sprintf('An unexpected value could not be serialized: %s', var_export($data, true)));
+    }
+
+    /**
+     * Selects the type of node to create and appends it to the parent.
+     *
+     * @param \DOMNode     $parentNode
+     * @param array|object $data
+     * @param string       $nodeName
+     * @param string       $key
+     *
+     * @return bool
+     */
+    private function appendNode(\DOMNode $parentNode, $data, $nodeName, $key = null)
+    {
+        $node = $this->dom->createElement($nodeName);
+        if (null !== $key) {
+            $node->setAttribute('key', $key);
+        }
+        $appendNode = $this->selectNodeType($node, $data);
+        // we may have decided not to append this node, either in error or if its $nodeName is not valid
+        if ($appendNode) {
+            $parentNode->appendChild($node);
+        }
+
+        return $appendNode;
+    }
+
+    /**
+     * Checks if a value contains any characters which would require CDATA wrapping.
+     *
+     * @param string $val
+     *
+     * @return bool
+     */
+    private function needsCdataWrapping($val)
+    {
+        return preg_match('/[<>&]/', $val);
+    }
+
+    /**
+     * Tests the value being passed and decide what sort of element to create.
+     *
+     * @param \DOMNode $node
+     * @param mixed    $val
+     *
+     * @return bool
+     */
+    private function selectNodeType(\DOMNode $node, $val)
+    {
+        if (is_array($val)) {
+            return $this->buildXml($node, $val);
+        } elseif ($val instanceof \SimpleXMLElement) {
+            $child = $this->dom->importNode(dom_import_simplexml($val), true);
+            $node->appendChild($child);
+        } elseif ($val instanceof \Traversable) {
+            $this->buildXml($node, $val);
+        } elseif (is_object($val)) {
+            return $this->buildXml($node, $this->serializer->normalize($val, $this->format, $this->context));
+        } elseif (is_numeric($val)) {
+            return $this->appendText($node, (string) $val);
+        } elseif (is_string($val) && $this->needsCdataWrapping($val)) {
+            return $this->appendCData($node, $val);
+        } elseif (is_string($val)) {
+            return $this->appendText($node, $val);
+        } elseif (is_bool($val)) {
+            return $this->appendText($node, (int) $val);
+        } elseif ($val instanceof \DOMNode) {
+            $child = $this->dom->importNode($val, true);
+            $node->appendChild($child);
+        }
+
+        return true;
+    }
+
+    /**
+     * Get real XML root node name, taking serializer options into account.
+     *
+     * @param array $context
+     *
+     * @return string
+     */
+    private function resolveXmlRootName(array $context = array())
+    {
+        return isset($context['xml_root_node_name'])
+            ? $context['xml_root_node_name']
+            : $this->rootNodeName;
+    }
+
+    /**
+     * Create a DOM document, taking serializer options into account.
+     *
+     * @param array $context options that the encoder has access to.
+     *
+     * @return \DOMDocument
+     */
+    private function createDomDocument(array $context)
+    {
+        $document = new \DOMDocument();
+
+        // Set an attribute on the DOM document specifying, as part of the XML declaration,
+        $xmlOptions = array(
+            // nicely formats output with indentation and extra space
+            'xml_format_output' => 'formatOutput',
+            // the version number of the document
+            'xml_version' => 'xmlVersion',
+            // the encoding of the document
+            'xml_encoding' => 'encoding',
+            // whether the document is standalone
+            'xml_standalone' => 'xmlStandalone',
+        );
+        foreach ($xmlOptions as $xmlOption => $documentProperty) {
+            if (isset($context[$xmlOption])) {
+                $document->$documentProperty = $context[$xmlOption];
+            }
+        }
+
+        return $document;
+    }
+}