laravel雄辩的模型更新事件未触发

圣诞快乐！

我是Laravel的新手.刚遇到一个初学者的问题，当我尝试使用服务提供商和模型事件来记录更新信息时.

I am new to Laravel. Just had a beginner's question, when I am trying to use service provider and model event to log the update information.

遵循在线文档: https://laravel.com/docs/5.3/eloquent#事件

将所有代码放在一起后，我发现仅在创建使用时触发模型事件，而在编辑用户时从不记录任何内容.

After put all code together, I find that the model event only fire when create the use but never log anything when I edit the user.

我错过了什么吗?感觉$ user没有被正确分配.这个从哪里来?来自其他服务提供商?

Did I miss anything? Feel like the $user didn't get assigned properly. Where is it from? from other service provider?

任何解释或提示将不胜感激！

Any explanation or hint will be appreciated!

<?php

namespace App\Providers;

use App\User;
use Illuminate\Support\ServiceProvider;

class AppServiceProvider extends ServiceProvider
{
    /**
     * Bootstrap any application services.
     *
     * @return void
     */
    public function boot()
    {
        User::creating(function ($user) {
            Log::info('event creating');
        });

        User::created(function ($user) {
            Log::info('event created');
        });

        User::updating(function ($user) {
            Log::info('event updating');
        });

        User::updated(function ($user) {
            Log::info('event updated');
        });

        User::saving(function ($user) {
            Log::info('event saving');
        });

        User::saved(function ($user) {
            Log::info('event saved');
        });

        User::deleting(function ($user) {
            Log::info('event deleting');
        });

        User::deleted(function ($user) {
            Log::info('event deleted');
        });
    }

    /**
     * Register the service provider.
     *
     * @return void
     */
    public function register()
    {
        //
    }
}