👀 Views: 0 💬 Answers: 1 📅 Created: 2025-06-16

angular rxjs httpclient typescript

Hey everyone, I'm running into an issue that's driving me crazy... I tried several approaches but none seem to work. I'm working on an Angular 15 application where I have a service that fetches user data and their associated posts from two different APIs. The question arises when I try to combine these two observables to return a single observable that has both user data and their posts. I want to ensure that the resulting observable only emits once both API calls have completed, but I'm running into issues with subscriptions and potential memory leaks. I've tried using `forkJoin` to wait for both requests to complete: ```typescript import { Injectable } from '@angular/core'; import { HttpClient } from '@angular/common/http'; import { forkJoin, Observable } from 'rxjs'; @Injectable({ providedIn: 'root' }) export class UserService { constructor(private http: HttpClient) {} getUserAndPosts(userId: string): Observable<any> { const userRequest = this.http.get(`https://api.example.com/users/${userId}`); const postsRequest = this.http.get(`https://api.example.com/users/${userId}/posts`); return forkJoin([userRequest, postsRequest]); } } ``` In my component, I'm subscribing to this service method: ```typescript import { Component, OnInit } from '@angular/core'; import { UserService } from './user.service'; @Component({ selector: 'app-user', templateUrl: './user.component.html' }) export class UserComponent implements OnInit { userData: any; userPosts: any[]; constructor(private userService: UserService) {} ngOnInit() { this.userService.getUserAndPosts('123').subscribe( ([user, posts]) => { this.userData = user; this.userPosts = posts; }, behavior => { console.behavior('behavior fetching user data and posts', behavior); } ); } } ``` While this seems to work fine, I'm worried that if the `UserComponent` gets destroyed while the HTTP requests are still in progress, it could lead to memory leaks or unexpected behaviors. I have considered using the `takeUntil` operator with a Subject to manage the subscription lifecycle, but I'm unsure of the best implementation pattern in this case. Additionally, I want to ensure that I handle any errors effectively and avoid any unhandled promise rejections. How can I safely handle this scenario while ensuring that I clean up subscriptions properly, and are there any best practices to follow for handling multiple nested observables in Angular? For context: I'm using Typescript on Ubuntu. Any ideas what could be causing this? My team is using Typescript for this desktop app. What's the correct way to implement this? Could this be a known issue?