laravel背包用户密码

我在背包里为我的用户做了一个crud。当我创建用户时，一切正常，但如果我更新，我会收到“密码”错误，因为如果我不想更新它，我会将其留空，密码不能为空。

如果我将其留空，如何才能不在 POST 中添加“密码”？或者我如何默认当前密码？还有一个“确认”字段？

在 UserCrudController.php 中

<?php 

    namespace App\Http\Controllers\Admin;

    use Backpack\CRUD\app\Http\Controllers\CrudController;
    use App\User;
    use Auth;

    // VALIDATION: change the requests to match your own file names if you need form validation
    use App\Http\Requests\UserCrudRequest as StoreRequest;
    use App\Http\Requests\UserCrudRequest as UpdateRequest;

    class UserCrudController extends CrudController {

        public function setup() {
            $this->crud->setModel("App\User");
            $this->crud->setRoute(config('backpack.base.route_prefix')."/user");
            $this->crud->setEntityNameStrings('user', 'users');

            $this->crud->setColumns([
                ['name' => 'lastname', 'label' => "Last Name"],
                ['name' => 'firstname', 'label' => "First Name"],

            ]);


            $this->crud->addFields([
                [
                    'name' => 'firstname',
                    'label' => "First name"
                ],
                [
                    'name' => 'lastname',
                    'label' => "First name"
                ],


                    [   // Password
                        'name' => 'password',
                        'label' => 'Password',
                        'type' => 'password'
                    ],

            ]);


        }

        public function store(StoreRequest $request)
        {
            // <---------  here is where a before_insert callback logic would be

            $response = parent::storeCrud();

            // <---------  here is where a after_insert callback logic would be

            return $response;
        }

        public function update(UpdateRequest $request)
        {
            $user = User::find(Auth::user()->id);

            // Hash password before save
            if (!empty($request->password)) {
                $request->offsetSet('password', Hash::make($request->password));
            }else{
                $request->offsetSet('password', $user->password );
            }

            return parent::updateCrud();
        }
    }

Error:

 Integrity constraint violation: 1048 Column 'password' cannot be null (SQL: update `users` set `password` = , `updated_at` = 2017-10-06 15:08:25 where `id` = 1)

如果有人正在为 Backpack 制作自己的 UserCrudController，请查看他们为权限管理器所做的控制器：

https://github.com/Laravel-Backpack/PermissionManager/blob/master/src/app/Http/Controllers/UserCrudController.php https://github.com/Laravel-Backpack/PermissionManager/blob/master/src/app/Http/Controllers/UserCrudController.php