switchmap

问题 I have a situation like the following: myObservable1.pipe( switchMap((result1: MyObservable1) => { if (condition) { return myObservable2; } else { return of(null); } }) ).subscribe(myObservable1 | myObservable2) => { So if condition is false I only have to perform one request, if the condition is true, I have to chain the first request to the following one, they are essentially two requests to the server api. Is there a better solution without returning that null ? Is there any conditional

问题 I have a situation like the following: myObservable1.pipe( switchMap((result1: MyObservable1) => { if (condition) { return myObservable2; } else { return of(null); } }) ).subscribe(myObservable1 | myObservable2) => { So if condition is false I only have to perform one request, if the condition is true, I have to chain the first request to the following one, they are essentially two requests to the server api. Is there a better solution without returning that null ? Is there any conditional

来源： https://stackoverflow.com/questions/63403939/angularfire-switchmap-calling-on-child-added-and-feeding-the-result-into-anoth

问题 I have a use case whenever a new request is triggered, any http requests that are already in flight should be cancelled / ignored. For eg : A request (say #2) comes in while the request #1 takes too long to respond / slow network connectivity. In this case #2 gets a very quick response from server then at any point even if the #1 comes back with a response the HTTP response observable should be ignored. The problem i face is, first the component displays response values from request #2 and

问题 before posting this i went to many other similar questions and not able to find solutions. like Angular 2 - Inject authorization token before each Http request I am using AWS session which provides me Authorization token for makeing HTTP request. Now getting session can be asynchronous operation depending on need to refresh token. Problem: I am not able to chain getting session and then making HTTP calls. Versions Angular 5, RxJs 5.5.2 AuthService's get session function. getSession():

问题 i tried canceling pending http request using subscription.unsubsribe like this: getAgentList(pageNumber: number, filter: string): any { let requestUrl: string = 'api/service/agents_search?ACCT=' +this.accountId; if ( this.subscription ) { this.subscription.unsubscribe(); } this.subscription = this.backEndCommService.getData(requestUrl) .subscribe( (res: any) => { let serverResponse: ServerResponse = new ServerResponse(this.accountId, pageNumber, res.search_results, res.resultRows, res