使用单个表单在用户注册的同时创建与用户相关的内容过滤器

Question

当用户注册时我希望在数据库中创建用户以及引用用户表中id的用户过滤器。我在表单中引用id时遇到了麻烦，但因为还没有创建用户。是否有任何代码可以工作：如果成功创建用户，请在此处使用其ID;插入过滤器对象user_id。

register.php

     $user = new User();
     $filter = new Filter();

            $salt = Hash::salt(32);

            try {{

                    $user->create(array(

                        'username' => Input::get('username'),
                        'password' => Hash::make(Input::get('password'), $salt),
                        'salt' => $salt,
                        'joined' => date('Y-m-d H:i:s'),
                        'group' => 1,
                        'email' => Input::get('email'),
                        'region' => Input::get('region'),
                        'country' => Input::get('country'),
                        'city_state' => Input::get('city_state')

                    ));

                    $filter->create(array(

                        'user_id' => WHAT DO I PUT HERE, OR IS THIS EVEN THE BEST WAY???
                        'tv'=> 1,
                        'video' => 1,
                        'mobile' => 1
                    ));

                    Session::flash('home', 'Thank you for registering. Enjoy filtwire!');
                    Redirect::to('index.php');

            }} catch(Exception $e){
                    die($e->getMessage());
            }

        } else {
            foreach($validation->errors() as $error) {
                echo $error, '<br>';
            }