Merge pull request #790 from schmittjoh/webservices-nl-fix-xml-nil-de…

…serialization

Detect XML xsi:nil="true" to null when deserializing

src/AbstractVisitor.php

@@ -62,5 +62,4 @@ protected function getElementType($typeArray)
             return $typeArray['params'][0];
         }
     }
-
 }

src/GraphNavigator.php

@@ -124,6 +124,11 @@ public function accept($data, array $type = null, Context $context)
         else if ($context instanceof SerializationContext && null === $data) {
             $type = array('name' => 'NULL', 'params' => array());
         }
+        // Sometimes data can convey null but is not of a null type.
+        // Visitors can have the power to add this custom null evaluation
+        if ($visitor instanceof NullAwareVisitorInterface && $visitor->isNull($data) === true) {
+            $type = array('name' => 'NULL', 'params' => array());
+        }
 
         switch ($type['name']) {
             case 'NULL':

src/NullAwareVisitorInterface.php

@@ -0,0 +1,32 @@
+<?php
+
+/*
+ * Copyright 2016 Johannes M. Schmitt <[email protected]>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+namespace JMS\Serializer;
+
+interface NullAwareVisitorInterface extends VisitorInterface
+{
+    /**
+     * Determine if a value conveys a null value.
+     * An example could be an xml element (Dom, SimpleXml, ...) that is tagged with a xsi:nil attribute
+     *
+     * @param mixed $value
+     *
+     * @return bool
+     */
+    public function isNull($value);
+}

src/XmlDeserializationVisitor.php

@@ -25,7 +25,7 @@
 use JMS\Serializer\Metadata\ClassMetadata;
 use JMS\Serializer\Metadata\PropertyMetadata;
 
-class XmlDeserializationVisitor extends AbstractVisitor
+class XmlDeserializationVisitor extends AbstractVisitor implements NullAwareVisitorInterface
 {
     private $objectStack;
     private $metadataStack;
@@ -387,4 +387,23 @@ private function getDomDocumentTypeEntitySubset($data)
 
         return $internalSubset;
     }
+
+    /**
+     * @param mixed $value
+     *
+     * @return bool
+     */
+    public function isNull($value)
+    {
+        if ($value instanceof \SimpleXMLElement) {
+            $xsiAttributes = $value->attributes('http://www.w3.org/2001/XMLSchema-instance');
+
+            //We have to keep the isset quiet, some tests give error: `Node no longer exists`; even though it evaluates to false
+            if (@isset($xsiAttributes['nil']) && (string) $xsiAttributes['nil'] === 'true') {
+                return true;
+            }
+        }
+
+        return $value === null;
+    }
 }

tests/Fixtures/ObjectWithNullProperty.php

@@ -18,7 +18,21 @@
 
 namespace JMS\Serializer\Tests\Fixtures;
 
+use JMS\Serializer\Annotation\Type;
+
 class ObjectWithNullProperty extends SimpleObject
 {
+    /**
+     * @var null
+     * @Type("string")
+     */
     private $nullProperty = null;
+
+    /**
+     * @return null
+     */
+    public function getNullProperty()
+    {
+        return $this->nullProperty;
+    }
 }

tests/Serializer/BaseSerializationTest.php

@@ -166,6 +166,25 @@ public function testSerializeNullObject()
         );
     }
 
+    public function testDeserializeNullObject()
+    {
+        if (!$this->hasDeserializer()) {
+            $this->markTestSkipped(sprintf('No deserializer available for format `%s`', $this->getFormat()));
+        }
+
+        $obj = new ObjectWithNullProperty('foo', 'bar');
+
+        /** @var ObjectWithNullProperty $dObj */
+        $dObj = $this->serializer->deserialize(
+            $this->getContent('simple_object_nullable'),
+            ObjectWithNullProperty::class,
+            $this->getFormat()
+        );
+
+        $this->assertEquals($obj, $dObj);
+        $this->assertNull($dObj->getNullProperty());
+    }
+
     /**
      * @dataProvider getTypes
      */

tests/Serializer/XmlSerializationTest.php

@@ -26,6 +26,7 @@
 use JMS\Serializer\Handler\HandlerRegistry;
 use JMS\Serializer\Metadata\StaticPropertyMetadata;
 use JMS\Serializer\Naming\CamelCaseNamingStrategy;
+use JMS\Serializer\Naming\PropertyNamingStrategyInterface;
 use JMS\Serializer\Naming\SerializedNameAnnotationStrategy;
 use JMS\Serializer\SerializationContext;
 use JMS\Serializer\Serializer;
@@ -52,6 +53,7 @@
 use JMS\Serializer\Tests\Fixtures\SimpleClassObject;
 use JMS\Serializer\Tests\Fixtures\SimpleObject;
 use JMS\Serializer\Tests\Fixtures\SimpleSubClassObject;
+use JMS\Serializer\XmlDeserializationVisitor;
 use JMS\Serializer\XmlSerializationVisitor;
 use PhpCollection\Map;
 
@@ -488,6 +490,16 @@ public function testDeserializeEmptyString()
         $this->deserialize('', 'stdClass');
     }
 
+    public function testEvaluatesToNull()
+    {
+        $namingStrategy = $this->getMockBuilder(PropertyNamingStrategyInterface::class)->getMock();
+        $visitor = new XmlDeserializationVisitor($namingStrategy);
+        $element = simplexml_load_string('<empty xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:nil="true"/>');
+
+        $this->assertTrue($visitor->isNull($element));
+        $this->assertTrue($visitor->isNull(null));
+    }
+
     private function xpathFirstToString(\SimpleXMLElement $xml, $xpath)
     {
         $nodes = $xml->xpath($xpath);