/TypeScript/Angular unsubscribe from observable

Angular unsubscribe from observable

//Please note that there are many ways to unsubscribe, this is one of them
import { Subscription } from 'rxjs';

private searchEventSubscription: Subscription;

export class someComponent OnInit, OnDestroy {

    constructor(private someService: SomeService) { }

    ngOnInit() {
      this.searchEventSubscription = this.someService.someMethod.subscribe(result => {  
        doSomething(result);
      });
    }

    ngOnDestroy() {
		this.searchEventSubscription.unsubscribe()
    }

Source: stackoverflow.com

import { Component, OnDestroy, OnInit } from '@angular/core';
// RxJs 6.x+ import paths
import { filter, startWith, takeUntil } from 'rxjs/operators';
import { Subject } from 'rxjs';
import { BookService } from '../books.service';

@Component({
    selector: 'app-books',
    templateUrl: './books.component.html'
})
export class BooksComponent implements OnDestroy, OnInit {
    private ngUnsubscribe = new Subject();

    constructor(private booksService: BookService) { }

    ngOnInit() {
        this.booksService.getBooks()
            .pipe(
               startWith([]),
               filter(books => books.length > 0),
               takeUntil(this.ngUnsubscribe)
            )
            .subscribe(books => console.log(books));

        this.booksService.getArchivedBooks()
            .pipe(takeUntil(this.ngUnsubscribe))
            .subscribe(archivedBooks => console.log(archivedBooks));
    }

    ngOnDestroy() {
        this.ngUnsubscribe.next();
        this.ngUnsubscribe.complete();
    }
}

Source: stackoverflow.com

import { Component, OnInit, OnDestroy } from '@angular/core';
import { HttpClient } from '@angular/common/http';

import { Subject } from 'rxjs';
import { takeUntil } from 'rxjs/operators';

interface User {
  id: string;
  name: string;
  age: number;
}

@Component({
  selector: 'app-foobar',
  templateUrl: './foobar.component.html',
  styleUrls: ['./foobar.component.scss'],
})
export class FoobarComponent implements OnInit, OnDestroy {
  private user: User = null;
  private destroy$ = new Subject();

  constructor(private http: HttpClient) {}

  ngOnInit() {
    this.http
      .get<User>('api/user/id')
      .pipe(takeUntil(this.destroy$))
      .subscribe(user => {
        this.user = user;
      });
  }

  ngOnDestroy(): void {
    this.destroy$.next();  // trigger the unsubscribe
    this.destroy$.complete(); // finalize & clean up the subject stream
  }
}

Source: stackoverflow.com

Similar codes

0 vote91 views1 answer
Automation over manual testing
TypeScript
0 vote141 views1 answer
Les différents types de cours
TypeScript
1 vote104 views1 answer
Replace \n with breakline in type scripte
TypeScript
0 vote143 views1 answer
Use AuthGuard with gRPC Metadata
TypeScript
1 vote97 views1 answer
What project management tool you use
TypeScript
0 vote158 views1 answer
How to get class weights while using keras imagedatagenerator
TypeScript
0 vote105 views1 answer
Admin_enqueue_scripts specific page
TypeScript
0 vote158 views1 answer
Try out the enumerate function for yourself in this quick exercise. Complete the skip_elements function to return every other element from the list, this time using the enumerate function to check if an element is on an even position or an odd positi
TypeScript
-1 vote102 views1 answer
Typescript array count
TypeScript
0 vote112 views1 answer
Vercel react redirects to index html
TypeScript