Improved EntityExporter to handle recursive exports

src/Serializer/StructuralElementNormalizer.php

@@ -51,7 +51,7 @@ class StructuralElementNormalizer implements NormalizerInterface
     /**
      * @return array<string, mixed>
      */
-    public function normalize($object, string $format = null, array $context = []): array
+    public function normalize($object, string $format = null, array $context = []): mixed
     {
         if (!$object instanceof AbstractStructuralDBElement) {
             throw new \InvalidArgumentException('This normalizer only supports AbstractStructural objects!');
@@ -59,6 +59,10 @@ class StructuralElementNormalizer implements NormalizerInterface
 
         $data = $this->normalizer->normalize($object, $format, $context);
 
+        if (!is_array($data)) {
+            return $data;
+        }
+
         //Remove type field for CSV export
         if ($format === 'csv') {
             unset($data['type']);

src/Services/ImportExportSystem/EntityExporter.php

@@ -23,9 +23,13 @@ declare(strict_types=1);
 namespace App\Services\ImportExportSystem;
 
 use App\Entity\Base\AbstractNamedDBElement;
+use App\Entity\Base\AbstractStructuralDBElement;
 use App\Helpers\FilenameSanatizer;
+use App\Serializer\APIPlatform\SkippableItemNormalizer;
 use Symfony\Component\OptionsResolver\OptionsResolver;
 use InvalidArgumentException;
+use Symfony\Component\Serializer\Exception\CircularReferenceException;
+use Symfony\Component\Serializer\Normalizer\AbstractNormalizer;
 use function is_array;
 use ReflectionClass;
 use ReflectionException;
@@ -97,10 +101,27 @@ class EntityExporter
                 'csv_delimiter' => $options['csv_delimiter'],
                 'xml_root_node_name' => 'PartDBExport',
                 'partdb_export' => true,
+                //Skip the item normalizer, so that we dont get IRIs in the output
+                SkippableItemNormalizer::DISABLE_ITEM_NORMALIZER => true,
+                //Handle circular references
+                AbstractNormalizer::CIRCULAR_REFERENCE_HANDLER => $this->handleCircularReference(...),
             ]
         );
     }
 
+    private function handleCircularReference(object $object, string $format, array $context): string
+    {
+        if ($object instanceof AbstractStructuralDBElement) {
+            return $object->getFullPath("->");
+        } elseif ($object instanceof AbstractNamedDBElement) {
+            return $object->getName();
+        } elseif ($object instanceof \Stringable) {
+            return $object->__toString();
+        }
+
+        throw new CircularReferenceException('Circular reference detected for object of type '.get_class($object));
+    }
+
     /**
      * Exports an Entity or an array of entities to multiple file formats.
      *