update code

app/Http/Requests/Document/ExportRequest.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace App\Http\Requests\Document;
+
+use Illuminate\Foundation\Http\FormRequest;
+
+class ExportRequest extends FormRequest
+{
+    /**
+     * Determine if the user is authorized to make this request.
+     *
+     * @return bool
+     */
+    public function authorize()
+    {
+        return $this->user()->hasPermissionTo('Báo cáo thống kê');
+    }
+
+    /**
+     * Get the validation rules that apply to the request.
+     *
+     * @return array
+     */
+    public function rules()
+    {
+        return [
+            'book' => 'nullable|exists:books,id',
+            'type' => 'nullable|exists:document_types,id',
+            'from' => 'nullable|date',
+            'to' => 'nullable|date',
+            'export' => 'required|in:Xlsx,Csv,Xls,Html',
+        ];
+    }
+}