Serialization of SplFixedArray and classes extending from it

Author: Nil Portugues Caldero

src/Serializer.php

@@ -12,6 +12,7 @@
 class Serializer
 {
     const CLASS_IDENTIFIER_KEY = '@type';
+    const CLASS_PARENT_KEY = '@parent';
     const SCALAR_TYPE = '@scalar';
     const SCALAR_VALUE = '@value';
     const NULL_VAR = null;
@@ -147,7 +148,7 @@ protected function serializeData($value)
             // @codeCoverageIgnoreEnd
         }
 
-        if (is_object($value) && $value instanceof \SplFixedArray) {
+        if ($this->isInstanceOf($value, 'SplFixedArray')) {
             return SplFixedArraySerializer::serialize($this, $value);
         }
 
@@ -161,6 +162,20 @@ protected function serializeData($value)
         return $this->$func($value);
     }
 
+    /**
+     * Check if a class is instance or extends from the expected instance.
+     *
+     * @param mixed  $value
+     * @param string $classFQN
+     *
+     * @return bool
+     */
+    private function isInstanceOf($value, $classFQN)
+    {
+        return is_object($value)
+        && (strtolower(get_class($value)) === strtolower($classFQN) || \is_subclass_of($value, $classFQN, true));
+    }
+
     /**
      * @param mixed $value
      *
@@ -224,7 +239,7 @@ protected function unserializeData($value)
             return $this->getScalarValue($value);
         }
 
-        if (isset($value[self::CLASS_IDENTIFIER_KEY]) && 0 === strcmp($value[self::CLASS_IDENTIFIER_KEY], 'SplFixedArray')) {
+        if (isset($value[self::CLASS_PARENT_KEY]) && 0 === strcmp($value[self::CLASS_PARENT_KEY], 'SplFixedArray')) {
             return SplFixedArraySerializer::unserialize($this, $value[self::CLASS_IDENTIFIER_KEY], $value);
         }
 

src/Serializer/InternalClasses/SplFixedArraySerializer.php

@@ -3,6 +3,7 @@
 namespace NilPortugues\Serializer\Serializer\InternalClasses;
 
 use NilPortugues\Serializer\Serializer;
+use ReflectionClass;
 use SplFixedArray;
 
 class SplFixedArraySerializer
@@ -17,6 +18,7 @@ public static function serialize(Serializer $serializer, SplFixedArray $splFixed
     {
         $toArray = [
             Serializer::CLASS_IDENTIFIER_KEY => get_class($splFixedArray),
+            Serializer::CLASS_PARENT_KEY => 'SplFixedArray',
             Serializer::SCALAR_VALUE => [],
         ];
         foreach ($splFixedArray->toArray() as $key => $field) {
@@ -31,12 +33,21 @@ public static function serialize(Serializer $serializer, SplFixedArray $splFixed
      * @param string     $className
      * @param array      $value
      *
-     * @return object
+     * @return mixed
      */
     public static function unserialize(Serializer $serializer, $className, array $value)
     {
         $data = $serializer->unserialize($value[Serializer::SCALAR_VALUE]);
 
-        return $className::fromArray($data);
+        /* @var SplFixedArray $instance */
+        $ref = new ReflectionClass($className);
+        $instance = $ref->newInstanceWithoutConstructor();
+
+        $instance->setSize(count($data));
+        foreach ($data as $k => $v) {
+            $instance[$k] = $v;
+        }
+
+        return $instance;
     }
 }

tests/DeepCopySerializerTest.php

@@ -20,6 +20,7 @@
 use NilPortugues\Test\Serializer\Dummy\ComplexObject\ValueObject\CommentId;
 use NilPortugues\Test\Serializer\Dummy\ComplexObject\ValueObject\PostId;
 use NilPortugues\Test\Serializer\Dummy\ComplexObject\ValueObject\UserId;
+use NilPortugues\Test\Serializer\SupportClasses\ChildOfSplFixedArray;
 use SplFixedArray;
 
 class DeepCopySerializerTest extends \PHPUnit_Framework_TestCase
@@ -92,4 +93,17 @@ public function testSplFixedArraySerialization()
 
         $this->assertEquals($splFixedArray, $serializer->unserialize($serializedObject));
     }
+
+    public function testSplFixedArrayChildSerialization()
+    {
+        $splFixedArray = new ChildOfSplFixedArray(3);
+        $splFixedArray[0] = 1;
+        $splFixedArray[1] = 2;
+        $splFixedArray[2] = 3;
+
+        $serializer = new DeepCopySerializer(new NullStrategy());
+        $serializedObject = $serializer->serialize($splFixedArray);
+
+        $this->assertEquals($splFixedArray, $serializer->unserialize($serializedObject));
+    }
 }

tests/SupportClasses/ChildOfSplFixedArray.php

@@ -0,0 +1,7 @@
+<?php
+
+namespace NilPortugues\Test\Serializer\SupportClasses;
+
+class ChildOfSplFixedArray extends \SplFixedArray
+{
+}