Angular 2 get service by string name

Question

Is there a way get an instance of an injectable service of angular 2 just by the service name?

For Example, in Angular 1 you could write:

var service = $injector.get('ServiceName');

and the service variable would get an instance of the service.

I'd really appreciate your help guys!

Defence

Answer 1

If you provide it by name, you can inject it by name

@NgModule({
  providers: [
      ServiceName, 
      {provide: 'ServiceName', useExisting: ServiceName}
  ],
  ...

Axe

How would I go about getting this service from a component? Using Injector.get is deprecated as of version 4 – Kolk

"Injector.get(token: any, notFoundValue?: any): any is now deprecated use the same method which is now overloaded as Injector.get<T>(token: Type<T>|InjectionToken<T>, notFoundValue?: T): T;" github.com/angular/angular/blob/master/… – Jamshedpur

Thanks for the info, but how would this be used in a component? I'm trying to upgrade the code from this answer to the 'new' format, but I can't wrap my head around the whole InjectionToken thing – Kolk

InjectionToken is just a key used to register a provider with and then to request an instance for this key with .get(...). – Jamshedpur

How would I get the key if it's passed as a string variable from a template? Example of what I mean (check out hello.component.ts) – Kolk

I see what you mean. Should work as explained in angular.io/api/core/InjectionToken#description. – Jamshedpur

Let us continue this discussion in chat. – Kolk

I'd suggest you create a new question. I'm quite out of practice with Angular. – Jamshedpur

downvoting answer, as it's incomplete - does not show how to access such service, only how to define name for a service. – Abalone

@MaciejMiklas that's shown in the question. – Jamshedpur

Answer 2

You can use Explicit injector creation using the Injector Class

injector = ReflectiveInjector.resolveAndCreate([ServiceClass, Dependency1Class, Dependency2Class]);

let service= injector.get(ServiceClass); //pass the type not the name

Network

That wasn't what the OP asked. – Pentagram

It's another option! I haven't contribute with stackoverflow anymore because of this kind of behavior. Options should be given. – Network

Unfortunately, this is not an option. The question clearly asks "just by the service name?", so offering a solution that just ignores that restriction is not helpful. – Unrestraint