Do I need to write a Route Resolver for every service call that implements a new interface?

Question

I have a question about routing in Angular 4, especially dealing with resolving the data.

My app will benefit greatly by implementing a route resolver; however, I am working on a complex web app and In one of my routes (a contact page) there are several components being rendered, each with a different service call to the back end. Each call is implementing a different interface. This is due to database restrictions.

Is their a way I can write 1 resolver for each of my services, or do I need to write a resolver for each service call that implements a new interface?

Answer 1

You can do everything in a single resolver, like so:

resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<any> {

     return Observable.forkJoin(
         this.someService.apiCallA(),
         this.someService.apiCallB(),
         this.someService.apiCallC(),
      )
      .map(([resA, resB, resC]: [ResponseAType, ResponseBType, ResponseCType]) => {
            return {
               aData: resA,
               bData: resB,
               cData: resC
            };

      });

}

Then in your main page component:

constructor(private aRoute: ActivatedRoute) {

      aRoute.data.subscribe((data: any) => {
         // You can find aData, bData, and cData here inside of data
         // Pass them down into the components that need them
      });

   }