javascript - Angular 2 router event listener

Question

How to listen state change in Angular 2 router?

In Angular 1.x I used this event:

$rootScope.$on('$stateChangeStart',
    function(event,toState,toParams,fromState,fromParams, options){ ... })

So, if I use this eventlistener in Angular 2:

window.addEventListener("hashchange", () => {return console.log('ok')}, false);

it isn't return 'ok', then change state from JS, only then browser history.back() function run.

Use router.subscribe() function as the service:

import {Injectable} from 'angular2/core';
import {Router} from 'angular2/router';

@Injectable()
export class SubscribeService {
    constructor (private _router: Router) {
        this._router.subscribe(val => {
            console.info(val, '<-- subscribe func');
        })
    }
}

Inject service in component which init in routing:

import {Component} from 'angular2/core';
import {Router} from 'angular2/router';

@Component({
    selector: 'main',
    templateUrl: '../templates/main.html',
    providers: [SubscribeService]
})
export class MainComponent {
    constructor (private subscribeService: SubscribeService) {}
}

I inject this service in other components such as in this example. Then I change state, console.info() in service not working.

What I do wrong?

Answer 1

new router

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

old

Inject the Router and subscribe to route change events

import {Router} from 'angular2/router';

class MyComponent {
  constructor(router:Router) {
    router.subscribe(...)
  }
}

NOTE

For the new router, don't forget to import NavigationStart from router module

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

because if you don't import it instanceof will not work and an error NavigationStart is not defined will rise.

See also

• https://angular.io/docs/ts/latest/api/router/index/Router-class.html
• How to detect a route change in Angular 2?