# Dependency injections

The handle method support dependency injections.

That means, whatever arguments you enter in the handle method, Laravel Actions will try to resolve them from the container but also from its own attributes. Let’s have a look at some examples.

// Resolved from the IoC container.
public function handle(Request $request) {/* ... */}
public function handle(MyService $service) {/* ... */}

// Resolved from the attributes.
// -- $title and $body are equivalent to $action->title and $action->body
// -- When attributes are missing, null will be returned unless a default value is provided.
public function handle($title, $body) {/* ... */}
public function handle($title, $body = 'default') {/* ... */}

// Resolved from the attributes using route model binding.
// -- If $action->comment is already an instance of Comment, it provides it.
// -- If $action->comment is an id, it will provide the right instance of 
//    Comment from the database or fail (just like it would in a controller).
//    This will also update $action->comment to be that instance.
public function handle(Comment $comment) {/* ... */}

// They can all be combined (in no particular order).
public function handle($title, Comment $comment, MyService $service) {/* ... */}

As you can see, both the action’s attributes and the IoC container are used to resolve dependency injections. When a matching attribute is type-hinted, the library will do its best to provide an instance of that class from the value of the attribute.


Note that almost every method that are meant for you to override (e.g. authorize, rules, handle, etc.) support dependency injections.