In Angular 1.x I would sometimes need to make multiple http requests and do something with all the responses. I would throw all the promises in an array and cal
The more straightforward alternative for emulating Promise.all is to use the forkJoin operator (it starts all observables in parallel and join their last elements):
A bit out of scope, but in case it helps, on the subject of chaining promises, you can use a simple flatMap : Cf. RxJS Promise Composition (passing data)