How to detect a route change in Angular?

Question

I am looking to detect a route change in my AppComponent.

Thereafter I will check the global user token to see if he is logged in. Then I can redirect t

Answer 1

RxJS 6

router.events.pipe(filter(event => event instanceof NavigationStart))

Thanks to Peilonrayz (see comments below)

new router >= RC.3

import { Router, NavigationStart, NavigationEnd, NavigationError, NavigationCancel, RoutesRecognized } from '@angular/router';

constructor(router:Router) {
  router.events.forEach((event) => {
    if(event instanceof NavigationStart) {
    }
    // NavigationEnd
    // NavigationCancel
    // NavigationError
    // RoutesRecognized
  });
}

You can also filter by the given event:

import 'rxjs/add/operator/filter';

constructor(router:Router) {
  router.events
    .filter(event => event instanceof NavigationStart)
    .subscribe((event:NavigationStart) => {
      // You only receive NavigationStart events
    });
}

Using the pairwise operator to get the previous and current event also is an nice idea. https://github.com/angular/angular/issues/11268#issuecomment-244601977

import 'rxjs/add/operator/pairwise';
import { Router } from '@angular/router;

export class AppComponent {
    constructor(private router: Router) {
        this.router.events.pairwise().subscribe((event) => {
            console.log(event);
        });
    };
}

Answer 2

Angular 7, if you want to subscribe to router

import { Router, NavigationEnd } from '@angular/router';

import { filter } from 'rxjs/operators';

constructor(
  private router: Router
) {
  router.events.pipe(
    filter(event => event instanceof NavigationEnd)  
  ).subscribe((event: NavigationEnd) => {
    console.log(event.url);
  });
}

Answer 3

In the component, you might want to try this:

import {NavigationEnd, NavigationStart, Router} from '@angular/router';

constructor(private router: Router) {
router.events.subscribe(
        (event) => {
            if (event instanceof NavigationStart)
                // start loading pages
            if (event instanceof NavigationEnd) {
                // end of loading paegs
            }
        });
}

Answer 4

Location works...

import {Component, OnInit} from '@angular/core';
import {Location} from '@angular/common';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss']
})

export class AppComponent implements OnInit {

    constructor(private location: Location) {
        this.location.onUrlChange(x => this.urlChange(x));
    }

    ngOnInit(): void {}

    urlChange(x) {
        console.log(x);
    }
}

Answer 5

above most of solutions correct , but i am facing issue this emit multiple times 'Navigation emit' event.when i was change any route this event is triggered. So hear is the complete solution for Angular 6.

import { Subscription } from 'rxjs/Subscription';
import 'rxjs/add/operator/do';
import 'rxjs/add/operator/filter';    

export class FooComponent implements OnInit, OnDestroy {
   private _routerSub = Subscription.EMPTY;
   constructor(private router: Router){}

   ngOnInit(){
     this._routerSub = this.router.events
      .filter(event => event instanceof NavigationEnd)
      .subscribe((value) => {
         //do something with the value
     });
  }

  ngOnDestroy(){
   this._routerSub.unsubscribe();
  }
} 

Answer 6

I do it like this since RC 5

this.router.events
  .map( event => event instanceof NavigationStart )
  .subscribe( () => {
    // TODO
  } );