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

vendor/symfony/serializer/Mapping/Loader/XmlFileLoader.php

@@ -0,0 +1,92 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Serializer\Mapping\Loader;
+
+use Symfony\Component\Config\Util\XmlUtils;
+use Symfony\Component\Serializer\Exception\MappingException;
+use Symfony\Component\Serializer\Mapping\AttributeMetadata;
+use Symfony\Component\Serializer\Mapping\ClassMetadataInterface;
+
+/**
+ * Loads XML mapping files.
+ *
+ * @author Kévin Dunglas <dunglas@gmail.com>
+ */
+class XmlFileLoader extends FileLoader
+{
+    /**
+     * An array of {@class \SimpleXMLElement} instances.
+     *
+     * @var \SimpleXMLElement[]|null
+     */
+    private $classes;
+
+    /**
+     * {@inheritdoc}
+     */
+    public function loadClassMetadata(ClassMetadataInterface $classMetadata)
+    {
+        if (null === $this->classes) {
+            $this->classes = array();
+            $xml = $this->parseFile($this->file);
+
+            foreach ($xml->class as $class) {
+                $this->classes[(string) $class['name']] = $class;
+            }
+        }
+
+        $attributesMetadata = $classMetadata->getAttributesMetadata();
+
+        if (isset($this->classes[$classMetadata->getName()])) {
+            $xml = $this->classes[$classMetadata->getName()];
+
+            foreach ($xml->attribute as $attribute) {
+                $attributeName = (string) $attribute['name'];
+
+                if (isset($attributesMetadata[$attributeName])) {
+                    $attributeMetadata = $attributesMetadata[$attributeName];
+                } else {
+                    $attributeMetadata = new AttributeMetadata($attributeName);
+                    $classMetadata->addAttributeMetadata($attributeMetadata);
+                }
+
+                foreach ($attribute->group as $group) {
+                    $attributeMetadata->addGroup((string) $group);
+                }
+            }
+
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Parses a XML File.
+     *
+     * @param string $file Path of file
+     *
+     * @return \SimpleXMLElement
+     *
+     * @throws MappingException
+     */
+    private function parseFile($file)
+    {
+        try {
+            $dom = XmlUtils::loadFile($file, __DIR__.'/schema/dic/serializer-mapping/serializer-mapping-1.0.xsd');
+        } catch (\Exception $e) {
+            throw new MappingException($e->getMessage(), $e->getCode(), $e);
+        }
+
+        return simplexml_import_dom($dom);
+    }
+}