title: Angular2 How can I Inject all interface implementation to service as list?
body: <p>I'm learning Angular2 with Typescript and I have a problem.</p>
  
  <p>I have two classe that imprements same interface. How can I inject them to a service as a list ?</p>
  
  <p>I read about opaquetoken <a href="https://angular.io/docs/ts/latest/guide/dependency-injection.html#opaquetoken" rel="noreferrer">https://angular.io/docs/ts/latest/guide/dependency-injection.html#opaquetoken</a> </p>
  
  <p>But I don't know if I need to use it and how to use it.</p>
  
  <pre><code>export interface CheckerInterface {
      check(text : string) : boolean
  }
  
  export class Checker1 implements CheckerInterface {
      check(text : string) : boolean {
      //do something 
      return true;
  }
  
  export class Checker2 implements CheckerInterface {
      check(text : string) : boolean {
      //do something 
      return true;
  }
  
  @Injectable()
  export class Service {
  
    constructor(private checkers: CheckerInterface[]) {  //??
        checkers.foreach( checker =&gt; checker.check(somestring));
    }
  
  }
  </code></pre>
  
  <p>Thanks for any help !</p>