How to detect a route change in Angular?

M

Marco

In Angular 2 you can subscribe (Rx event) to a Router instance. So you can do things like

class MyClass {
  constructor(private router: Router) {
    router.subscribe((val) => /*whatever*/)
  }
}

Edit (since rc.1)

class MyClass {
  constructor(private router: Router) {
    router.changes.subscribe((val) => /*whatever*/)
  }
}

Edit 2 (since 2.0.0)

see also : Router.events doc

class MyClass {
  constructor(private router: Router) {
    router.events.subscribe((val) => {
        // see also 
        console.log(val instanceof NavigationEnd) 
    });
  }
}

I am able to get data by event._root.children[0].value._routeConfig.data I hope there can be better way

@Akshay have you seen this article by Todd Motto: [Dynamic page titles in Angular 2 with router events] (toddmotto.com/dynamic-page-titles-angular-2-router-events)

why does it fire 3 times?

you can filter the events easily with RxJS filter operator. router.events.pipe(filter(e => e instanceof NavigationEnd).subscribe((e) => { ... }

@Simon_Weaver iam not sure but i think you forgot a closing bracket before .subscribe(

E

ElliotSchmelliot

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); }); }; }

@GunterZochbauer instead of 'is' I would use 'instanceof'. And 'event: Event' should be in parentheses. Thanks for this, pretty powerful new feature! I like it

This does throw a compilation error on the current versions Argument of type '(event: Event) => void' is not assignable to parameter of type

@RudiStrydom & Günter Zöchbauer - the Argument of type '(event: Event) => void' is not assignable to parameter of type error is because in your filter snippet you are subscribing to an object of type Event instead of NavigationEvent.

Second sample should be NavigationEvent instead of Event. Also dont forget to import "Event as NavigationEvent" from @angular/router

The hint about the import was for anyone looking to solve this error :)

P

Pini Cheyni

For Angular 7 someone should write like:

this.router.events.subscribe((event: Event) => {})

A detailed example can be as follows:

import { Component } from '@angular/core'; 
import { Router, Event, NavigationStart, NavigationEnd, NavigationError } from '@angular/router';

@Component({
    selector: 'app-root',
    template: `<router-outlet></router-outlet>`
})
export class AppComponent {

    constructor(private router: Router) {

        this.router.events.subscribe((event: Event) => {
            if (event instanceof NavigationStart) {
                // Show loading indicator
            }

            if (event instanceof NavigationEnd) {
                // Hide loading indicator
            }

            if (event instanceof NavigationError) {
                // Hide loading indicator

                // Present error to user
                console.log(event.error);
            }
        });

   }
}

This is great! very comprehensive! worked perfectly on Angular 7.

Usually the navigation itself takes very little time if you use preloading strategy. In terms of usability I would use loading indicators only on backend http requests, if at all.

In the constructor, you should not use , your case is for ngOnInit.

Perfect, How can I get exact param.id of url ?

The solution is not component limited, it spreads throughout the app, consuming resources

P

Pini Cheyni

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);
  });
}

it does not capture the redirect event

@AnandhuAjayakumar Of course yes it works ! the event has two properties url and urlAfterRedirects, in case of a redirect the event has url set to from which path redirection is made and urlAfterRedirects set to path after redirect

A

Aravind

Angular 4.x and above :

This can be achieved using url property of ActivatedRoute class as below,

this.activatedRoute.url.subscribe(url =>{
     console.log(url);
});

Note: That you need to import and inject the provider from angular/router package

import { ActivatedRoute } from '@angular/router`

and

constructor(private activatedRoute : ActivatedRoute){  }

P

Pini Cheyni

In Angular 8 you should do like this.router.events.subscribe((event: Event) => {})

Example:

import { Component } from '@angular/core'; 
import { Router, Event } from '@angular/router';
import { NavigationStart, NavigationError, NavigationEnd } from '@angular/router';

@Component({
    selector: 'app-root',
    template: `<router-outlet></router-outlet>`
})
export class AppComponent {

    constructor(private router: Router) {
        //Router subscriber
        this.router.events.subscribe((event: Event) => {
            if (event instanceof NavigationStart) {
                //do something on start activity
            }

            if (event instanceof NavigationError) {
                // Handle error
                console.error(event.error);
            }

            if (event instanceof NavigationEnd) {
                //do something on end activity
            }
        });
   }
}

P

Pini Cheyni

In angular 6 and RxJS6:

import { filter, debounceTime } from 'rxjs/operators';

 this.router.events.pipe(
      filter((event) => event instanceof NavigationEnd),
      debounceTime(40000)
    ).subscribe(
      x => {
      console.log('val',x);
      this.router.navigate(['/']); /*Redirect to Home*/
}
)

you missed import for Router import {Router, NavigationEnd} from "@angular/router"

M

Mike Lallemont

Router 3.0.0-beta.2 should be

this.router.events.subscribe(path => {
  console.log('path = ', path);
});

that works for current path but what about previous?

J

Jeffrey Nicholson Carré

In Angular 10, you can do something like the following...

    import { Component, OnInit } from '@angular/core';
    import { Router, NavigationEnd } from '@angular/router';
    import { filter } from 'rxjs/operators';
    
    @Component({
      selector: 'app-my-class',
      templateUrl: './my-class.component.html',
      styleUrls: ['./my-class.component.scss']
    })
    export class MyClassComponent implements OnInit {
      constructor(private router: Router) {}
    
      ngOnInit(): void {
        this.router.events
        .pipe(filter(event => event instanceof NavigationEnd))  
        .subscribe((event: NavigationEnd) => {
          // code goes here...
        });
      }
    }

sir i have redirect to another page after subscribe but its redirected ?

C

Community

The answers here are correct for router-deprecated. For the latest version of router:

this.router.changes.forEach(() => {
    // Do whatever in here
});

or

this.router.changes.subscribe(() => {
     // Do whatever in here
});

To see the difference between the two, please check out this SO question.

Edit

For the latest you must do:

this.router.events.subscribe(event: Event => {
    // Handle route change
});

Does it provide any data of previous and current route?

The router has been updated again (I haven't updated my answer yet), so I'm not sure how it is for the latest. For the router I wrote about, you couldn't. @akn

Please could you provide some context for this answer? which lines are you replacing in the other solutions with yours?

b

baduker

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
            }
        });
}

w

webmaster_sean

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);
    }
}

N

Narottam Goyal

Capture route change events in the following manner...

import { Component, OnInit, Output, ViewChild } from "@angular/core";
import { Router, NavigationStart, NavigationEnd, Event as NavigationEvent } from '@angular/router';

@Component({
    selector: "my-app",
    templateUrl: "app/app.component.html",
    styleUrls: ["app/app.component.css"]
})
export class AppComponent {

    constructor(private cacheComponentObj: CacheComponent,
        private router: Router) {

        /*  Route event types
            NavigationEnd
            NavigationCancel
            NavigationError
            RoutesRecognized
        */
        router.events.forEach((event: NavigationEvent) => {

            //Before Navigation
            if (event instanceof NavigationStart) {
                switch (event.url) {
                case "/app/home":
                {
                    //Do Work
                    break;
                }
                case "/app/About":
                {
                    //Do Work
                    break;
                }
                }
            }

            //After Navigation
            if (event instanceof NavigationEnd) {
                switch (event.url) {
                case "/app/home":
                {
                    //Do Work
                    break;
                }
                case "/app/About":
                {
                    //Do Work
                    break;
                }
                }
            }
        });
    }
}

Perfect, How can I get exact param.id of url ?

A

Ashique razak

If you're trying to access the current route while listening to route change:

router.events.pipe(filter(r=>r instanceof NavigationEnd)).subscribe(r=>{
      console.log((r as NavigationEnd).url);
    });

y

yala ramesh

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();
  }
}

R

Rebai Ahmed

Updated answer for those who are using Angular9+, By using Router API provided by @angular/router and listening for route changes

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

    @Component({
      selector: 'my-app',
      templateUrl: './app.component.html',
      styleUrls: [ './app.component.css' ]
    })
    export class AppComponent  {
      
      name = 'Get Current Url Route Demo';
      currentRoute: string;
     routeSubscription: subscription;
    
      constructor(private router: Router){
        console.log(router.url);
        
        this.routeSubscription = router.events.filter(event => event instanceof NavigationEnd)
              .subscribe(event => 
               {
                  this.currentRoute = event.url;          
                  console.log(event);
               });
        }
    }

L

LalithSwarna

I would write something like this:

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

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

K

Khaled Al-Ansari

@Ludohen answer is great, but in case you don't want to use instanceof use the following

this.router.events.subscribe(event => {
  if(event.constructor.name === "NavigationStart") {
    // do something...
  }
});

with this way you can check the current event name as a string and if the event occurred you can do what you planned your function to do.

why not use typescript safety?

there is no hate just vote down! thats an atom problem.

@Pascal no it's an Angular problem since the router event is not the same as the browser event and that's why the Event type won't work! they need to create a new interface for this event, I should've said that from the beginning but the unreasonable down vote didn't help :)

since minification is performed in production code you should rather use instanceOf so your example will work in production code too. if(event instanceOf NavigationStart) {

Should be if(event instanceof NavigationStart)

A

Ankit Singh

In Angular 7, I have solved using the below function for enabling and disabling the navbar on specific pages.

First you should import NavigationEnd

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

navbar.component.ts

public isNavbar=false;
ngAfterViewInit() {

    // nabar enable / disable function
    this.router.events.subscribe((event) => {
        if (event instanceof NavigationEnd) {   
            if(event.url.includes('dashboard')){
                this.isNavbar=true;
              }else{
                this.isNavbar=false;
              }
        }
    });
}

navbar.component.html

<mat-toolbar *ngIf="isNavbar" class="mat-elevation-z1 nav-tool-bar">
<button mat-button routerLink="/dashboard" routerLinkActive="active-list-item"><svg aria-hidden="true" focusable="false" data-prefix="fal" data-icon="paper-plane" role="img" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="nav-bar-icon svg-inline--fa fa-paper-plane fa-w-16"><path fill="currentColor" d="M464 4.3L16 262.7C-7 276-4.7 309.9 19.8 320L160 378v102c0 30.2 37.8 43.3 56.7 20.3l60.7-73.8 126.4 52.2c19.1 7.9 40.7-4.2 43.8-24.7l64-417.1C515.7 10.2 487-9 464 4.3zM192 480v-88.8l54.5 22.5L192 480zm224-30.9l-206.2-85.2 199.5-235.8c4.8-5.6-2.9-13.2-8.5-8.4L145.5 337.3 32 290.5 480 32l-64 417.1z" class=""></path></svg>
    Campagnes</button>
<button mat-button routerLink="fake" routerLinkActive="active-list-item"><svg aria-hidden="true" focusable="false" data-prefix="fal" data-icon="box-open" role="img" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 608 512" class="nav-bar-icon svg-inline--fa fa-box-open fa-w-19"><path fill="currentColor" d="M606.4 143.8L557.5 41c-2.7-5.6-8.1-9-13.9-9C543 32 304 64 304 64S65 32 64.4 32c-5.8 0-11.2 3.5-13.9 9L1.6 143.8c-4.4 9.2.3 20.2 9.6 23l49.5 14.9V393c0 14.7 9.5 27.5 23 31l205.4 54.1c13 3.4 23.7 1.5 29.5 0L524.2 424c13.5-3.6 23-16.4 23-31V181.7l49.5-14.9c9.4-2.8 14-13.8 9.7-23zM73 65.3l180.9 24.3-57.1 99.8-159.9-48.1 36.1-76zm18.2 125.6C208.3 226.1 200.5 224 203.6 224c5.4 0 10.5-2.9 13.3-7.9l71.9-125.5V445L91.2 393V190.9zM516.8 393l-197.6 52V90.5L391.1 216c2.9 5 8 7.9 13.3 7.9 3.1 0-5 2.1 112.4-33.1V393zM411.3 189.3l-57.1-99.8L535 65.3l36.1 76-159.8 48z" class=""></path></svg>
    Ressources</button>
<button mat-button routerLink="fake" routerLinkActive="active-list-item"><svg aria-hidden="true" focusable="false" data-prefix="fal" data-icon="life-ring" role="img" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="nav-bar-icon svg-inline--fa fa-life-ring fa-w-16"><path fill="currentColor" d="M256 8C119.033 8 8 119.033 8 256s111.033 248 248 248 248-111.033 248-248S392.967 8 256 8zm168.766 113.176l-62.885 62.885a128.711 128.711 0 0 0-33.941-33.941l62.885-62.885a217.323 217.323 0 0 1 33.941 33.941zM256 352c-52.935 0-96-43.065-96-96s43.065-96 96-96 96 43.065 96 96-43.065 96-96 96zM363.952 68.853l-66.14 66.14c-26.99-9.325-56.618-9.33-83.624 0l-66.139-66.14c66.716-38.524 149.23-38.499 215.903 0zM121.176 87.234l62.885 62.885a128.711 128.711 0 0 0-33.941 33.941l-62.885-62.885a217.323 217.323 0 0 1 33.941-33.941zm-52.323 60.814l66.139 66.14c-9.325 26.99-9.33 56.618 0 83.624l-66.139 66.14c-38.523-66.715-38.5-149.229 0-215.904zm18.381 242.776l62.885-62.885a128.711 128.711 0 0 0 33.941 33.941l-62.885 62.885a217.366 217.366 0 0 1-33.941-33.941zm60.814 52.323l66.139-66.14c26.99 9.325 56.618 9.33 83.624 0l66.14 66.14c-66.716 38.524-149.23 38.499-215.903 0zm242.776-18.381l-62.885-62.885a128.711 128.711 0 0 0 33.941-33.941l62.885 62.885a217.323 217.323 0 0 1-33.941 33.941zm52.323-60.814l-66.14-66.14c9.325-26.99 9.33-56.618 0-83.624l66.14-66.14c38.523 66.715 38.5 149.229 0 215.904z" class=""></path></svg>Support</button></mat-toolbar>

navbar.component.scss

.mat-toolbar {
    padding-top: 2px;
    padding-left: 30px;
    background-color: #fff;
  }
  ::ng-deep .nav-tool-bar{
    button{
     .mat-button-focus-overlay{
       opacity: 0!important;
     }
     .nav-bar-icon{
       width: 16px;
     }
     span{
      font-size: 15px;
     }
    }
    .active-list-item{
        background-color: #c79652;
        span{
          color: #fff;
          font-size: 15px;
          svg{
            path{
              color: #fff;
            }
          }
        }
    }
  }

Important to changes SCSS .active-list-item background color.

B

Bhagvat Lande

I am working with angular5 application and i'm facing the same issue . when i go through Angular Documentation they provide best solution for handling router events.check following documentation.

Router Events in Angular Route events in angular5

But specifically for the case provide in question we need NavigationEnd Event Navigation End Event Angular

Represents an event triggered when a navigation ends successfully

How to use this ?

import { Component, OnInit } from '@angular/core';
import { Router, ActivatedRouteSnapshot, NavigationEnd } from '@angular/router';
@Component({
    selector: 'app-navbar',
    templateUrl: './navbar.component.html',
    styleUrls: ['./navbar.component.css']
})
export class NavbarComponent implements OnInit {
    constructor(private router: Router) { }
    ngOnInit(): void {
        //calls this method when navigation ends
        this.router.events.subscribe(event => {
            if (event instanceof NavigationEnd) {
                //calls this stuff when navigation ends
                console.log("Event generated");
            }
        });
    }
}

When to use this ?

In my case my application share common dashboard for all users such as users , Admins , but i need to show and hides some navbar options as per user types.

That's why whenever url changes i need to call service method which returns logged in user information as per response i will go for further operations.

b

brg

The following KIND of works and may do the tricky for you.

// in constructor of your app.ts with router and auth services injected
router.subscribe(path => {
    if (!authService.isAuthorised(path)) //whatever your auth service needs
        router.navigate(['/Login']);
    });

Unfortunately this redirects later in the routing process than I'd like. The onActivate() of the original target component is called before the redirect.

There is a @CanActivate decorator you can use on the target component but this is a) not centralised and b) does not benefit from injected services.

It would be great if anyone can suggest a better way of centrally authorising a route before it is committed. I'm sure there must be a better way.

This is my current code (How would I change it to listen to the route change?):

import {Component, View, bootstrap, bind, provide} from 'angular2/angular2';
import {ROUTER_BINDINGS, RouterOutlet, RouteConfig, RouterLink, ROUTER_PROVIDERS, APP_BASE_HREF} from 'angular2/router';    
import {Location, LocationStrategy, HashLocationStrategy} from 'angular2/router';

import { Todo } from './components/todo/todo';
import { About } from './components/about/about';

@Component({
    selector: 'app'
})

@View({
    template: `
        <div class="container">
            <nav>
                <ul>
                    <li><a [router-link]="['/Home']">Todo</a></li>
                    <li><a [router-link]="['/About']">About</a></li>
                </ul>
            </nav>
            <router-outlet></router-outlet>
        </div>
    `,
    directives: [RouterOutlet, RouterLink]
})

@RouteConfig([
    { path: '/', redirectTo: '/home' },
    { path: '/home', component: Todo, as: 'Home' },
    { path: '/about', component: About, as: 'About' }
])

class AppComponent {    
    constructor(location: Location){
        location.go('/');
    }    
}    
bootstrap(AppComponent, [ROUTER_PROVIDERS, provide(APP_BASE_HREF, {useValue: '/'})]);

I've seen folks extend the routerOutlet to add their auth code which is one way. There's talk on gitHub about it but no conclusion yet.. Here's Auth0's way: auth0.com/blog/2015/05/14/…

Thank you for your response. Do you know any good videos for learning the authService for angular 2?

j

jirig

I do it like this since RC 5

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

S

Shy Agam

The cleaner way to do this would be to inherit RouteAware and implement the onNavigationEnd() method.

It's part of a library called @bespunky/angular-zen.

npm install @bespunky/angular-zen Make your AppComponent extend RouteAware and add an onNavigationEnd() method.

import { Component     } from '@angular/core';
import { NavigationEnd } from '@angular/router';
import { RouteAware    } from '@bespunky/angular-zen/router-x';

@Component({
    selector   : 'app-root',
    templateUrl: './app.component.html',
    styleUrls  : ['./app.component.css']
})
export class AppComponent extends RouteAware
{    
    protected onNavigationEnd(event: NavigationEnd): void
    {
        // Handle authentication...
    }
}

RouteAware has other benefits such as: ✨ Any router event can have a handler method (Angular's supported router events). ✨ Use this.router to access the router ✨ Use this.route to access the activated route ✨ Use this.componentBus to access the RouterOutletComponentBus service

N

Naeem Bashir

im using this way:

class ClassName {
  constructor(private router: Router) {
    router.events.subscribe((value) => {
        // see this 
        console.log(value instanceof NavigationEnd) 
    });
  }
}

Ö

Ömer Faruk Kırlı

if you just want to check route/query paramater changes like localhost:4200/users/1?edit=1 to localhost:4200/users/2?edit=0 you can use params observable like below.

import { ActivatedRoute, Params } from '@angular/router';
export class SomeClass implements OnInit {

paramFromRoute;

constructor(private route: ActivatedRoute) { }

ngOnInit() {
  this.paramFromRoute = this.route.snapshot.params['paramName']; // this one is required for getting it first time

  this.route.params.subscribe((params:Params)=>{
    this.paramFromRoute =  params['paramName'] // whenever route is changed, this function will triggered.
  });
  // for queryParams you can subscribe to this.route.queryParams
 }   
}

A

Akshay Mondal

You can use the following to detect the route change:

import { Router, ActivatedRoute} from '@angular/router'; constructor(private route: ActivatedRoute) {} this.router.events.subscribe((event) => { if(event) { //do something } });

P

Pullat Junaid

Just make changes on AppRoutingModule like

@NgModule({
imports: [RouterModule.forRoot(routes, { scrollPositionRestoration: 'enabled' })],
  exports: [RouterModule]
})

7

7guyo

Angular 8. Check whether the current route is the base route.

  baseroute: boolean;
  constructor(
    private router: Router,
  ) {
    router.events.subscribe((val: any) => {
      if (val.url == "/") {
        this.baseroute = true;
      } else {
        this.baseroute = false;
      }
    });
  }

e

er-Chaan

simple answer for Angular 8.*

constructor(private route:ActivatedRoute) {
  console.log(route);
}

Isn't this only executed on instantiation, that would be: only once!? This is not a solution.

How to detect a route change in Angular?

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