Delay does not stop the ajax call for being executed

[acostaf]

Hi Guys

using delay just send the next item when the time is due but still makes the ajax call immediately.

How can I delay the call to the server side ?

[paulpdaniels]

You can use either .delaySubscription or a higher-order Observable to do it.

// With Delay Subscription
ajaxRequest.delaySubscription(500).subscribe(processResult);

// With HOO
Observable.timer(500).flatMapLatest(ajaxRequest).subscribe(processResult);

[acostaf]

Hi Paul, thanks for the quick answer.

Is ajaxRequest an observable ?

I am getting an error with delaySubscription saying that delaySubscription is not found ( https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operators/delaysubscription.md).

[paulpdaniels]

@acostaf yes it is a place holder for whatever your ajax call will be.

What version of RxJS are you using?

[acostaf]

5.0.2

[paulpdaniels]

Ah ok. I need to start leading with that next time. You are in the wrong repo. V5 was moved to https://github.com/ReactiveX/rxjs.

AFAIK v5 does not have delaySubscription so you would be left with the second approach I outlined, but it would be Observable.timer(500).switchMapTo(ajaxRequest).subscribe(processResult); instead.

You can try posting in the other repo or SO as well if you don't feel that adequately answers your question.

[acostaf]

Ok, will try it tomorrow, thanks for your help.

[acostaf]

Thanks Paul that worked.

[maruthi-menlo]

@paulpdaniels I need to stop the obeservable.timer in ngOnDestroy. It is not working for me. Can you please help me on this.

FYI.. Below is the code using in my project. this.serverUrlSubscription = this.serverUrlStream .debounce((val)=> Observable.timer(initial ? 0 : 500))
.filter(val => !!val) .switchMap(val =>{
this.canLeave = false;
this.apiClientService.ocServiceUrl = val; return Observable.fromPromise(this.apiClientService.getHospitals()); }) .catch((err, caught)=>{ console.log(err); return caught;
}).subscribe((hospitals: Hospital[]) => { this.hospitals = hospitals; if (hospitals.length > 0) { this.settings.hospitalInstallId = hospitals[0].InstallId;
this.canLeave = true;
this.cd.detectChanges(); } });

So every 500ms this.apiClientService.getHospitals() http call is firing. This is fine but I need to stop this http call when I move to other page. So I tried in ngOnDestroy to kill that http call . Code: ngOnDestroy(){ this.serverUrlSubscription.unsubscribe(); }

When I move to next page this ngOnDestory is firing but at the same time http call is executing every 500ms. unsuscribe() is not working here. Please suggest.