Form submission export request as seprate class with validation

api/app/Http/Controllers/Forms/FormSubmissionController.php

@@ -5,6 +5,7 @@
 use App\Exports\FormSubmissionExport;
 use App\Http\Controllers\Controller;
 use App\Http\Requests\AnswerFormRequest;
+use App\Http\Requests\FormSubmissionExportRequest;
 use App\Http\Resources\FormSubmissionResource;
 use App\Jobs\Form\StoreFormSubmissionJob;
 use App\Models\Forms\Form;
@@ -14,7 +15,6 @@
 use Illuminate\Support\Str;
 use Maatwebsite\Excel\Facades\Excel;
 use Vinkla\Hashids\Facades\Hashids;
-use Illuminate\Http\Request;
 
 class FormSubmissionController extends Controller
 {
@@ -47,14 +47,9 @@ public function update(AnswerFormRequest $request, $id, $submissionId)
         ]);
     }
 
-    public function export(Request $request, string $id)
+    public function export(FormSubmissionExportRequest $request, string $id)
     {
-        $request->validate([
-            'columns' => 'required|array',
-            'columns.*' => 'boolean'
-        ]);
-
-        $form = Form::findOrFail((int) $id);
+        $form = $request->form;
         $this->authorize('view', $form);
 
         $allRows = [];

api/app/Http/Requests/FormSubmissionExportRequest.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace App\Http\Requests;
+
+use App\Models\Forms\Form;
+use Illuminate\Foundation\Http\FormRequest;
+use Illuminate\Http\Request;
+
+class FormSubmissionExportRequest extends FormRequest
+{
+    public Form $form;
+
+    public function __construct(Request $request)
+    {
+        $this->form = Form::findOrFail($request->route('id'));
+    }
+
+    public function rules()
+    {
+        $validColumns = collect(array_merge(
+            $this->form->properties,
+            $this->form->removed_properties ?? []
+        ))->pluck('id')->toArray();
+        $validColumns[] = 'created_at';
+
+        return [
+            'columns' => 'required|array',
+            'columns.*' => ['boolean', 'required'],
+            'columns' => [function ($attribute, $value, $fail) use ($validColumns) {
+                $submittedColumns = array_keys($value);
+                $invalidColumns = array_diff($submittedColumns, $validColumns);
+                if (!empty($invalidColumns)) {
+                    $fail('The columns contain invalid values: ' . implode(', ', $invalidColumns));
+                }
+            }],
+        ];
+    }
+}