Solutions to problems encountered when setting up lazy loading during Laravel Service Provider development

Recently when developing the laravel-database-logger package, I found that setting the ServiceProvider defer property to true will result in registration in the register method. The middleware is invalid. This article mainly shares with you the solutions to the problems encountered when setting up lazy loading during Laravel Service Provider development. I hope it can help everyone.

class ServiceProvider extends \Illuminate\Support\ServiceProvider
{
     protected $defer = true;
     
     public function register()
     {
        $this->mergeConfigFrom(
            __DIR__ . '/../config/config.php', 'ibrand.dblogger'
        );


        $this->app->singleton(DbLogger::class, function ($app) {
            return new DbLogger();
        });

        //当 $defer 设置为 true 时，在路由中引用 databaselogger middleware 会报错，提示 databaselogger class not found.
        $this->app[\Illuminate\Routing\Router::class]->middleware('databaselogger', Middleware::class);

    }
    
    public function provides()
    {
        return [DbLogger::class];
    }
}

When the problem occurred, I suspected that it was caused by setting the defer attribute to true. I immediately modified the source code to protected $defer = true; code is commented out, and the result is still the prompt databaselogger class not found., indicating that Laravel has not registered this ServiceProvder

The next step is what to do To solve this problem, I tried the following methods:

1. Verify whether there is a problem with your own code

Register yourself in the normally registered AppServiceProvider After the ServiceProvider

public function register()
    {
        //
        $this->app->register(\Ibrand\DatabaseLogger\ServiceProvider::class);
    }

was registered, everything was normal.

2. Study the source code
The registration of providers in config/app.php is invalid, but in other ServiceProvider# If the registration in ## is valid, it means there is another problem.

Find the

registerConfiguredProviders method by studying the Illuminate\Foundation\Application source code:

Laravel reads

config/ in this method providers content in app.php and load to ProviderRepository.

(new ProviderRepository($this, new Filesystem, $this->getCachedServicesPath()))
                    ->load($providers->collapse()->toArray());

The key point is

$this->getCachedServicesPath(). Through the source code, we found that Laravel determines how to register based on the bootstrap/cache/services.php fileServiceProvider.

At this time, I thought of the reason why the previously commented

//protected $defer = true; code was still invalid.

So in order for the commented

//protected $defer = true; to be effective, the code needs to be executed.

php artisan clear-compiled 
php artisan optimize

After that, the problem is solved and I have a deeper understanding of ServiceProvider. principle.

So remember: If you plan to use delayed loading

ServiceProvider, it is strictly prohibited to register middleware, route and other series of operations. At the same time, after changing the defer attribute value, you need to execute php artisan clear-compiled and php artisan optimize to update the ServiceProvider cache.

3. Why is registration in AppServiceProvider valid?

It is very simple, because

AppServiceProvider is not delayed loading, so the register method in AppServiceProvider is executed to register a new oneServiceProvider will not be delayed loaded either.

Summary

1. Use lazy loading with caution

   ServiceProvider

2. Change

   defer After setting the attribute value, php artisan clear-compiled and php artisan optimize need to be executed to update the ServiceProvider cache.

3. It is strictly prohibited to register

   middleware and route in lazy-loaded ServiceProvider.

Related recommendations:

Detailed explanation of laravel5's method of creating service provider and facade

Laravel Service Providers question

How to create service provider and facade in laravel5

The above is the detailed content of Solutions to problems encountered when setting up lazy loading during Laravel Service Provider development. For more information, please follow other related articles on the PHP Chinese website!