feat: implement custom serializer to handle attribute filtering

src/Serializers/DataArraySerializer.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace Apiato\Core\Serializers;
+
+use Illuminate\Support\Facades\Request;
+use League\Fractal\Serializer\ArraySerializer;
+
+class DataArraySerializer extends ArraySerializer
+{
+    public function collection(string|null $resourceKey, array $data): array
+    {
+        return $this->filterResponse($data);
+    }
+
+    private function filterResponse(array $data): array
+    {
+        if ($requestFilters = Request::get('filter')) {
+            return ['data' => $this->filterResponseRecursively($data, explode(';', $requestFilters))];
+        }
+
+        return compact('data');
+    }
+
+    private function filterResponseRecursively(array $responseArray, array $filters): array
+    {
+        foreach ($responseArray as $key => $value) {
+            if (in_array($key, $filters, true)) {
+                // we have found our element - so continue with the next one
+                continue;
+            }
+
+            if (is_array($value)) {
+                // it is an array - so go one step deeper
+                $value = $this->filterResponseRecursively($value, $filters);
+                $responseArray[$key] = $value;
+            } elseif (!in_array($key, $filters, true)) {
+                unset($responseArray[$key]);
+            }
+        }
+
+        return $responseArray;
+    }
+
+    public function item(string|null $resourceKey, array $data): array
+    {
+        return $this->filterResponse($data);
+    }
+
+    public function null(): array|null
+    {
+        return ['data' => []];
+    }
+}