For your use case, I think that the flatMap operator is what you need: this.userData.getUserPhotos(‘123456’).flatMap(data => { this.userPhotos = data; return this.userData.getUserInfo(); }).subscribe(data => { this.userInfo = data; }); This way, you will execute the second request once the first one is received. The flatMap operator is particularly useful when you want to use the … Read more
Since http calls and the like are async, you get an Observable instead of a synchronous value returned. You have to subscribe to it, and in the callback in there you get the data. There is no way around that. One option would be to place your logic in the subscribe call getSomething() { return … Read more
Please include your view and model next time (app/about/about.html and about.model). If you are returning an array, you can use the asyncPipe, which “subscribes to an Observable or Promise and returns the latest value it has emitted. When a new value is emitted, the async pipe marks the component to be checked for changes” hence … Read more
Update 2016-06-27: instead of using Observables, use either a BehaviorSubject, as recommended by @Abdulrahman in a comment, or a ReplaySubject, as recommended by @Jason Goemaat in a comment A Subject is both an Observable (so we can subscribe() to it) and an Observer (so we can call next() on it to emit a new value). … Read more
TL;DR For this question there are two kinds of Observables – finite value and infinite value. http Observables produce finite (1) values and something like a DOM event listener Observable produces infinite values. If you manually call subscribe (not using async pipe), then unsubscribe from infinite Observables. Don’t worry about finite ones, RxJs will take … Read more
Reason: The reason that it’s undefined is that you are making an asynchronous operation. Meaning it’ll take some time to complete the getEventList method (depending mostly on your network speed). So lets look at the http call. this.es.getEventList() After you actually make (“fire”) your http request with subscribe you will be waiting for the response. … Read more