|string> */ public function rules(): array { $rules = [ 'title' => 'required|string|max:255', 'type' => 'required|string|max:255', 'resource' => 'nullable|string|max:255', 'resource_url' => 'nullable|string|max:255', ]; if ($this->isMethod('post')) { $rules['exam_id'] = 'required|exists:exams,id'; } return $rules; } }