Rxjs Observable.concat: How To Know Where Next Result Came From?

My application (Angular 2 with RxJS 5 written in TypeScript) requires me to make 2 calls to a web service in a predefined order. Inspired by this page I decided to try the concat o

Solution 1:

You could mapthe suscriptions to know where it's coming from.

suscription1 = Observable.return({name:'John', age:7})
         .map(person => { person.source = 1; return person };
subscription2 = Observable.return({name:'Mary', age:8})
         .map(person => { person.source = 2; return person };

Then you can easily determine where it comes from:

Observable.concat(subscription1, subscription2).subscribe(
    data=> { if (data.source == 1) /* do whatever */ }
);