Binding Basics

Simple Bindings

Within a service provider, you always have access to the container via the $this->app property. We can register a binding using the bind method, passing the class or interface name that we wish to register along with a Closure that returns an instance of the class:

$this->app->bind('HelpSpot\API', function ($app) {
    return new HelpSpot\API($app->make('HttpClient'));
});

Note that we receive the container itself as an argument to the resolver. We can then use the container to resolve sub-dependencies of the object we are building.

Binding A Singleton

The singleton method binds a class or interface into the container that should only be resolved one time. Once a singleton binding is resolved, the same object instance will be returned on subsequent calls into the container:

$this->app->singleton('HelpSpot\API', function ($app) {
    return new HelpSpot\API($app->make('HttpClient'));
});

Binding Instances

You may also bind an existing object instance into the container using the instance method. The given instance will always be returned on subsequent calls into the container:

$api = new HelpSpot\API(new HttpClient);

$this->app->instance('HelpSpot\API', $api);

Binding Primitives

Sometimes you may have a class that receives some injected classes, but also needs an injected primitive value such as an integer. You may easily use contextual binding to inject any value your class may need:

$this->app->when('App\Http\Controllers\UserController')
          ->needs('$variableName')
          ->give($value);

Service Container