diff --git a/src/lib/Output/Generator/AbstractFieldTypeHashGenerator.php b/src/lib/Output/Generator/AbstractFieldTypeHashGenerator.php
new file mode 100644
index 00000000..ceffc72b
--- /dev/null
+++ b/src/lib/Output/Generator/AbstractFieldTypeHashGenerator.php
@@ -0,0 +1,142 @@
+<?php
+
+/**
+ * @copyright Copyright (C) Ibexa AS. All rights reserved.
+ * @license For full copyright and license information view LICENSE file distributed with this source code.
+ */
+
+namespace Ibexa\Rest\Output\Generator;
+
+use Ibexa\Rest\Output\Generator\Data\ArrayList;
+use Ibexa\Rest\Output\Generator\Json\ArrayObject;
+use Ibexa\Rest\Output\Generator\Json\JsonObject;
+use Psr\Log\LoggerAwareInterface;
+use Psr\Log\LoggerAwareTrait;
+use Psr\Log\LoggerInterface;
+use Psr\Log\NullLogger;
+use Symfony\Component\Serializer\Exception\ExceptionInterface;
+use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+
+abstract class AbstractFieldTypeHashGenerator implements LoggerAwareInterface
+{
+    use LoggerAwareTrait;
+
+    private NormalizerInterface $normalizer;
+
+    private bool $strictMode;
+
+    public function __construct(
+        NormalizerInterface $normalizer,
+        ?LoggerInterface $logger = null,
+        bool $strictMode = false
+    ) {
+        $this->normalizer = $normalizer;
+        $this->logger = $logger ?? new NullLogger();
+        $this->strictMode = $strictMode;
+    }
+
+    /**
+     * Generates the field type value $hashValue as a child of the given Object
+     * using $hashElementName as the property name.
+     */
+    public function generateHashValue(
+        JsonObject|ArrayObject|ArrayList $parent,
+        string $hashElementName,
+        mixed $hashValue
+    ): void {
+        $parent->$hashElementName = $this->generateValue($parent, $hashValue);
+    }
+
+    /**
+     * Generates and returns a JSON structure (array or object) depending on $value type
+     * with $parent.
+     *
+     * If $type only contains numeric keys, the resulting structure will be an
+     * JSON array, otherwise a JSON object
+     *
+     * @param array<mixed> $value
+     */
+    protected function generateArrayValue(
+        JsonObject|ArrayObject|ArrayList $parent,
+        array $value,
+    ): JsonObject|ArrayObject|ArrayList {
+        if ($this->isNumericArray($value)) {
+            return $this->generateListArray($parent, $value);
+        } else {
+            return $this->generateHashArray($parent, $value);
+        }
+    }
+
+    /**
+     * Generates and returns a value based on $hashValue type, with $parent (
+     * if the type of $hashValue supports it).
+     */
+    abstract protected function generateValue(JsonObject|ArrayObject|ArrayList $parent, mixed $value): mixed;
+
+    /**
+     * Checks if the given $value is a purely numeric array.
+     *
+     * @param array<mixed> $value
+     */
+    protected function isNumericArray(array $value): bool
+    {
+        foreach (array_keys($value) as $key) {
+            if (is_string($key)) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    protected function generateObjectValue(JsonObject|ArrayObject|ArrayList $parent, object $value): mixed
+    {
+        try {
+            $value = $this->normalizer->normalize($value, 'json', ['parent' => $parent]);
+        } catch (ExceptionInterface $e) {
+            if ($this->strictMode) {
+                throw $e;
+            }
+            $message = sprintf(
+                'Unable to normalize value for type "%s". %s. '
+                . 'Ensure that a normalizer is registered with tag: "%s".',
+                get_class($value),
+                $e->getMessage(),
+                'ibexa.rest.serializer.normalizer',
+            );
+
+            assert($this->logger instanceof LoggerInterface);
+            $this->logger->error($message, [
+                'exception' => $e,
+            ]);
+
+            $value = null;
+        }
+
+        if (is_array($value)) {
+            return $this->generateArrayValue($parent, $value);
+        }
+
+        return $value;
+    }
+
+    /**
+     * Generates a JSON array from the given $hashArray with $parent.
+     *
+     * @param array<int> $listArray
+     */
+    abstract protected function generateListArray(
+        JsonObject|ArrayObject|ArrayList $parent,
+        array $listArray,
+    ): JsonObject|ArrayObject|ArrayList;
+
+    /**
+     * Generates a JSON object from the given $hashArray with $parent.
+     *
+     * @param array<mixed> $hashArray
+     */
+    abstract protected function generateHashArray(
+        JsonObject|ArrayObject|ArrayList $parent,
+        array $hashArray,
+    ): JsonObject|ArrayObject|ArrayList;
+}
diff --git a/src/lib/Output/Generator/Json/FieldTypeHashGenerator.php b/src/lib/Output/Generator/Json/FieldTypeHashGenerator.php
index 31b369ee..69456be4 100644
--- a/src/lib/Output/Generator/Json/FieldTypeHashGenerator.php
+++ b/src/lib/Output/Generator/Json/FieldTypeHashGenerator.php
@@ -4,57 +4,16 @@
  * @copyright Copyright (C) Ibexa AS. All rights reserved.
  * @license For full copyright and license information view LICENSE file distributed with this source code.
  */
+declare(strict_types=1);
 
 namespace Ibexa\Rest\Output\Generator\Json;
 
-use Psr\Log\LoggerAwareInterface;
-use Psr\Log\LoggerAwareTrait;
-use Psr\Log\LoggerInterface;
-use Psr\Log\NullLogger;
-use Symfony\Component\Serializer\Exception\ExceptionInterface;
-use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+use Ibexa\Rest\Output\Generator\AbstractFieldTypeHashGenerator;
+use Ibexa\Rest\Output\Generator\Data\ArrayList;
 
-class FieldTypeHashGenerator implements LoggerAwareInterface
+class FieldTypeHashGenerator extends AbstractFieldTypeHashGenerator
 {
-    use LoggerAwareTrait;
-
-    private NormalizerInterface $normalizer;
-
-    private bool $strictMode;
-
-    public function __construct(
-        NormalizerInterface $normalizer,
-        ?LoggerInterface $logger = null,
-        bool $strictMode = false
-    ) {
-        $this->normalizer = $normalizer;
-        $this->logger = $logger ?? new NullLogger();
-        $this->strictMode = $strictMode;
-    }
-
-    /**
-     * Generates the field type value $hashValue as a child of the given Object
-     * using $hashElementName as the property name.
-     *
-     * @param \Ibexa\Rest\Output\Generator\Json\ArrayObject|\Ibexa\Rest\Output\Generator\Json\JsonObject|\Ibexa\Rest\Output\Generator\Data\ArrayList $parent
-     * @param string $hashElementName
-     * @param mixed $hashValue
-     */
-    public function generateHashValue($parent, $hashElementName, $hashValue)
-    {
-        $parent->$hashElementName = $this->generateValue($parent, $hashValue);
-    }
-
-    /**
-     * Generates and returns a value based on $hashValue type, with $parent (
-     * if the type of $hashValue supports it).
-     *
-     * @param \Ibexa\Rest\Output\Generator\Json\ArrayObject|\Ibexa\Rest\Output\Generator\Json\JsonObject $parent
-     * @param mixed $value
-     *
-     * @return mixed
-     */
-    protected function generateValue($parent, $value)
+    protected function generateValue(JsonObject|ArrayObject|ArrayList $parent, mixed $value): mixed
     {
         if ($value === null || is_scalar($value)) {
             // Will be handled accordingly on serialization
@@ -72,37 +31,10 @@ protected function generateValue($parent, $value)
         throw new \Exception('Invalid type in Field value hash: ' . get_debug_type($value));
     }
 
-    /**
-     * Generates and returns a JSON structure (array or object) depending on $value type
-     * with $parent.
-     *
-     * If $type only contains numeric keys, the resulting structure will be an
-     * JSON array, otherwise a JSON object
-     *
-     * @param \Ibexa\Rest\Output\Generator\Json\ArrayObject|\Ibexa\Rest\Output\Generator\Json\JsonObject $parent
-     * @param array<mixed> $value
-     *
-     * @return \Ibexa\Rest\Output\Generator\Json\ArrayObject|\Ibexa\Rest\Output\Generator\Json\JsonObject
-     */
-    protected function generateArrayValue($parent, array $value)
-    {
-        if ($this->isNumericArray($value)) {
-            return $this->generateListArray($parent, $value);
-        } else {
-            return $this->generateHashArray($parent, $value);
-        }
-    }
-
-    /**
-     * Generates a JSON array from the given $hashArray with $parent.
-     *
-     * @param \Ibexa\Rest\Output\Generator\Json\ArrayObject|\Ibexa\Rest\Output\Generator\Json\JsonObject|\Ibexa\Rest\Output\Generator\Data\ArrayList $parent
-     * @param array<int> $listArray
-     *
-     * @return \Ibexa\Rest\Output\Generator\Json\ArrayObject|JsonObject
-     */
-    protected function generateListArray($parent, array $listArray)
-    {
+    protected function generateListArray(
+        JsonObject|ArrayObject|ArrayList $parent,
+        array $listArray,
+    ): JsonObject|ArrayObject|ArrayList {
         $arrayObject = new ArrayObject($parent);
         foreach ($listArray as $listItem) {
             $arrayObject->append($this->generateValue($arrayObject, $listItem));
@@ -111,16 +43,10 @@ protected function generateListArray($parent, array $listArray)
         return $arrayObject;
     }
 
-    /**
-     * Generates a JSON object from the given $hashArray with $parent.
-     *
-     * @param \Ibexa\Rest\Output\Generator\Json\ArrayObject|\Ibexa\Rest\Output\Generator\Json\JsonObject $parent
-     * @param array<mixed> $hashArray
-     *
-     * @return \Ibexa\Rest\Output\Generator\Json\JsonObject
-     */
-    protected function generateHashArray($parent, array $hashArray)
-    {
+    protected function generateHashArray(
+        JsonObject|ArrayObject|ArrayList $parent,
+        array $hashArray,
+    ): JsonObject|ArrayObject|ArrayList {
         $object = new JsonObject($parent);
         foreach ($hashArray as $hashKey => $hashItem) {
             $object->$hashKey = $this->generateValue($object, $hashItem);
@@ -128,56 +54,4 @@ protected function generateHashArray($parent, array $hashArray)
 
         return $object;
     }
-
-    /**
-     * Checks if the given $value is a purely numeric array.
-     *
-     * @param array $value
-     *
-     * @return bool
-     */
-    protected function isNumericArray(array $value)
-    {
-        foreach (array_keys($value) as $key) {
-            if (is_string($key)) {
-                return false;
-            }
-        }
-
-        return true;
-    }
-
-    /**
-     * @param \Ibexa\Rest\Output\Generator\Json\ArrayObject|\Ibexa\Rest\Output\Generator\Json\JsonObject $parent
-     *
-     * @return mixed
-     */
-    protected function generateObjectValue($parent, object $value)
-    {
-        try {
-            $value = $this->normalizer->normalize($value, 'json', ['parent' => $parent]);
-        } catch (ExceptionInterface $e) {
-            if ($this->strictMode) {
-                throw $e;
-            }
-            $message = sprintf(
-                'Unable to normalize value for type "%s". %s. '
-                . 'Ensure that a normalizer is registered with tag: "%s".',
-                get_class($value),
-                $e->getMessage(),
-                'ibexa.rest.serializer.normalizer',
-            );
-            $this->logger->error($message, [
-                'exception' => $e,
-            ]);
-
-            $value = null;
-        }
-
-        if (is_array($value)) {
-            return $this->generateArrayValue($parent, $value);
-        }
-
-        return $value;
-    }
 }
diff --git a/src/lib/Output/Generator/Xml/FieldTypeHashGenerator.php b/src/lib/Output/Generator/Xml/FieldTypeHashGenerator.php
index d8f107c3..9c12dc01 100644
--- a/src/lib/Output/Generator/Xml/FieldTypeHashGenerator.php
+++ b/src/lib/Output/Generator/Xml/FieldTypeHashGenerator.php
@@ -8,12 +8,14 @@
 
 namespace Ibexa\Rest\Output\Generator\Xml;
 
-use Ibexa\Rest\Output\Generator\Json\FieldTypeHashGenerator as JsonFieldTypeHashGenerator;
+use Ibexa\Rest\Output\Generator\AbstractFieldTypeHashGenerator;
+use Ibexa\Rest\Output\Generator\Data\ArrayList;
+use Ibexa\Rest\Output\Generator\Json\ArrayObject;
 use Ibexa\Rest\Output\Generator\Json\JsonObject;
 
-final class FieldTypeHashGenerator extends JsonFieldTypeHashGenerator
+final class FieldTypeHashGenerator extends AbstractFieldTypeHashGenerator
 {
-    protected function generateValue($parent, $value): mixed
+    protected function generateValue(JsonObject|ArrayObject|ArrayList $parent, mixed $value): mixed
     {
         if ($value === null) {
             return null;
@@ -30,17 +32,10 @@ protected function generateValue($parent, $value): mixed
         }
     }
 
-    protected function generateArrayValue($parent, $value): JsonObject
-    {
-        if ($this->isNumericArray($value)) {
-            return $this->generateListArray($parent, $value);
-        } else {
-            return $this->generateHashArray($parent, $value);
-        }
-    }
-
-    protected function generateListArray($parent, array $listArray): JsonObject
-    {
+    protected function generateListArray(
+        JsonObject|ArrayObject|ArrayList $parent,
+        array $listArray,
+    ): JsonObject|ArrayObject|ArrayList {
         $object = new JsonObject($parent);
         $object->value = [];
 
@@ -53,8 +48,10 @@ protected function generateListArray($parent, array $listArray): JsonObject
         return $object;
     }
 
-    protected function generateHashArray($parent, array $hashArray): JsonObject
-    {
+    protected function generateHashArray(
+        JsonObject|ArrayObject|ArrayList $parent,
+        array $hashArray,
+    ): JsonObject|ArrayObject|ArrayList {
         $object = new JsonObject($parent);
         $object->value = [];