How to wait with function execution until subscription is completed?

Question

I want to subscribe to an Observable and then execute another function. My problem is, it takes a moment until the request is finished. However, the code just continues with its execution immediatly after the subscription has started.

I need some information that will be there after the Subscription is complete. Without that data, transformShopList() will fail. When I run the code, this is what happens.

How can you wait for the Subscription to finish, and then go on with the rest of the statements?

this.observable3.subscribe(
  ...
);
// wait here?
this.transformShopList();

Have you tried a `.then()`? `this.observable3.subscribe().then(function(){ .. })` — Anurag Srivastava, Mar 21 '19 at 14:40
No, would other statements after the then(...) also wait for .then to be finished? — Marie M., Mar 21 '19 at 14:54
You should include the functions you want to execute after the `.subscribe` is complete, inside the `.then()` — Anurag Srivastava, Mar 21 '19 at 15:08

score 0 · Answer 1 · answered Mar 21 '19 at 14:40

0

You'll have this problem whatever you do in Javascript. Asynchronous tasks must be chained. Either with Promise, Observable or callback functions.

The right code is

this.observable3.subscribe((...) => {
  ...
  this.transformShopList();
});

answered Mar 21 '19 at 14:40

Guerric P

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score 0 · Answer 2 · answered Mar 21 '19 at 14:41

0

An observable emits an event and your subscription receives it. Move your transform shop list inside the subscription response and it will execute when the observable emits.

https://angular.io/guide/observables

answered Mar 21 '19 at 14:41

Lockless

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How to wait with function execution until subscription is completed?

2 Answers2

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