Currently, I'm working on my first Laravel package. So, it was time to dive into the wonderful world of the service container and service providers.

Laravel has some great docs about, but I wanted to see some real-world examples for myself. And what better way than to have a look at the packages that you already depend on?

This post details the different things that a service provider can be used for, each taken from a real open-source project. I've linked to the source of each example.

Additions:
15/11: defining an alias.
15/11: registering sub-dependencies.
16/11: registering middleware.
16/11: registering an event handler.

First of, you should probably have a look at the docs for the service container, service providers and package development.

You can register a service provider by adding it to the providers array in config/app.php like so:

'providers' => [
    // Other Service Providers
    App\Providers\MyCustomServiceProvider::class,
],

Now, let's look at some common scenario's that you can find in service providers.

Binding

Common binding. Taken from spatie/laravel-glide.

public function register()
{
    $this->app->bind('laravel-glide-image', function () {
        return new GlideImage();
    });
}

Singleton binding. Taken from cviebrock/eloquent-sluggable.

public function register()
{
    $this->app->singleton(SluggableObserver::class, function ($app) {
        return new SluggableObserver(new SlugService(), $app['events']);
     });
}

Instance binding. Taken from spatie/laravel-googletagmanager.

public function register()
{
    $googleTagManager = new GoogleTagManager(config('googletagmanager.id'));

    if (config('googletagmanager.enabled') === false) {
        $googleTagManager->disable();
    }

    $this->app->instance('Spatie\GoogleTagManager\GoogleTagManager', $googleTagManager);
}

Define an alias. Taken from graham-campbell/htmlmin.

public function register()
{
    $this->app->alias('htmlmin.css', CssMinifier::class);
}

Register and alias for a sub-dependency. Found on http://stackoverflow.com/a/22749871/404423.

public function register()
{
    $this->app->register('LucaDegasperi\OAuth2Server\OAuth2ServerServiceProvider');

    $this->app->alias('AuthorizationServer', 'LucaDegasperi\OAuth2Server\Facades\AuthorizationServerFacade');
    $this->app->alias('ResourceServer', 'LucaDegasperi\OAuth2Server\Facades\ResourceServerFacade');
}

Resources

The following examples are about publishing resources so they can be used throughout the application.

Configuration. Taken from mcamara/laravel-localization.

public function boot()
{
    $this->publishes([
        __DIR__ . '/../../config/config.php' => config_path('laravellocalization.php'),
    ], 'config');
}

public function register()
{
    $packageConfigFile = __DIR__ . '/../../config/config.php';

    $this->mergeConfigFrom(
        $packageConfigFile, 'laravellocalization'
    );
}

Views. Taken from laracasts/flash.

public function boot()
{
    $this->loadViewsFrom(__DIR__ . '/../../views', 'flash');

    $this->publishes([
        __DIR__ . '/../../views' => base_path('resources/views/vendor/flash')
    ]);
}

Commands. Taken from jeroen-g/laravel-packager.

protected $commands = [
    'JeroenG\Packager\PackagerNewCommand',
    ...
    'JeroenG\Packager\PackagerTestsCommand',
];

public function register()
{
    $this->commands($this->commands);
}

Migrations. Taken from: waavi/translation.

public function boot()
{
    $this->publishes([
        __DIR__ . '/../database/migrations/' => database_path('migrations'),
    ], 'migrations');
}

Translations. Taken from: laravelrus/localized-carbon.

public function boot()
{
    $this->loadTranslationsFrom(__DIR__.'/../../lang', 'localized-carbon');

    $this->publishes([
        __DIR__.'/../../lang' => base_path('resources/lang'),
    ]);
}

Middleware. Taken from: barryvdh/laravel-cors.

public function boot()
{
    $this->app['router']->middleware('cors', HandleCors::class);
}

Others

Defer loading. Register bindings only if they are requested. Can only be used for registering bindings. Taken from antonioribeiro/google2fa.

protected $defer = true;

public function register()
{
    $this->app->bind(
       'PragmaRX\Google2FA\Contracts\Google2FA',
       'PragmaRX\Google2FA\Google2FA'
    );
}

public function provides()
{
    return ['PragmaRX\Google2FA\Contracts\Google2FA'];
}

Register an event handler. Taken from sentry/sentry-laravel.

public function boot()
{
    ...
    $this->bindEvents($this->app);
    ...
}

protected function bindEvents($app)
{
    $handler = new SentryLaravelEventHandler($app['sentry'], $app['sentry.config']);
    $handler->subscribe($app->events);
}

Set event listener. Taken from: jenssegers/date.

public function boot()
{
    $this->app['events']->listen('locale.changed', function () {
        $this->setLocale();
    });

    $this->setLocale();
}

protected function setLocale()
{
    $locale = $this->app['translator']->getLocale();

    Date::setLocale($locale);
}

Adding a Blade directive. Taken from spatie/laravel-blade-javascript.

public function boot()
{
    Blade::directive('javascript', function ($expression) {
        $expression = $this->makeBackwardsCompatible($expression);

        return "<?= app('\Spatie\BladeJavaScript\Renderer')->render{$expression}; ?>";
    });
}

Do you have more examples of how service providers should be used? Do you think these are the right examples to learn from? Share your opinion in the comments below!

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