Angular 2: getting RouteParams from parent component

UPDATE:

Now that Angular2 final was officially released, the correct way to do this is the following:

export class ChildComponent {

    private sub: any;

    private parentRouteId: number;

    constructor(private route: ActivatedRoute) { }

    ngOnInit() {
        this.sub = this.route.parent.params.subscribe(params => {
            this.parentRouteId = +params["id"];
        });
    }

    ngOnDestroy() {
        this.sub.unsubscribe();
    }
}

---

ORIGINAL:

Here is how i did it using the "@angular/router": "3.0.0-alpha.6" package:

export class ChildComponent {

    private sub: any;

    private parentRouteId: number;

    constructor(
        private router: Router,
        private route: ActivatedRoute) {
    }

    ngOnInit() {
        this.sub = this.router.routerState.parent(this.route).params.subscribe(params => {
            this.parentRouteId = +params["id"];
        });
    }

    ngOnDestroy() {
        this.sub.unsubscribe();
    }
}

In this example the route has the following format: /parent/:id/child/:childid

export const routes: RouterConfig = [
    {
        path: '/parent/:id',
        component: ParentComponent,
        children: [
            { path: '/child/:childid', component: ChildComponent }]
    }
];

You shouldn't try to use RouteParams in your ChildOneComponent.

Use RouteRegistry, instead!

@Component({
  ...
})

export class ChildOneComponent {

  public username: string;

  constructor(registry: RouteRegistry, location: Location) {
    route_registry.recognize(location.path(), []).then((instruction) => {
      console.log(instruction.component.params['username']);
    })
  }


  ...
}

UPDATE: As from this pull request (angular beta.9): https://github.com/angular/angular/pull/7163

You can now access to the current instruction without recognize(location.path(), []).

Example:

@Component({
  ...
})

export class ChildOneComponent {

  public username: string;

  constructor(_router: Router) {
    let instruction = _router.currentInstruction();
    this.username = instruction.component.params['username'];
  }

  ...
}

I haven't tried it, yet

Further details here:

https://github.com/angular/angular/blob/master/CHANGELOG.md#200-beta9-2016-03-09 https://angular.io/docs/ts/latest/api/router/Router-class.html

UPDATE 2: A small change as from angular 2.0.0.beta15:

Now currentInstruction is not a function anymore. Moreover, you have to load the root router. (thanks to @Lxrd-AJ for reporting)

@Component({
  ...
})

export class ChildOneComponent {

  public username: string;

  constructor(_router: Router) {
    let instruction = _router.root.currentInstruction;
    this.username = instruction.component.params['username'];
  }

  ...
}