How to detect a route change in Angular?

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);
        });
    };
}

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);
            }
        });

   }
}

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);
  });
}

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){  }

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
            }
        });
   }
}

Router 3.0.0-beta.2 should be

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

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(["https://stackoverflow.com/"]); /*Redirect to Home*/
}
)

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
});

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...
        });
      }
    }

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
            }
        });
}

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);
    }
}

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;
                }
                }
            }
        });
    }
}

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);
    });

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();
  }
} 

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);
               });
        }
    }

@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.

I would write something like this:

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

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

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.

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: "https://stackoverflow.com/", redirectTo: '/home' },
    { path: '/home', component: Todo, as: 'Home' },
    { path: '/about', component: About, as: 'About' }
])

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

I do it like this since RC 5

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

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.

1. npm install @bespunky/angular-zen

2. 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

im using this way:

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

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
 }   
}

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.

Just make changes on AppRoutingModule like

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

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 == "https://stackoverflow.com/") {
        this.baseroute = true;
      } else {
        this.baseroute = false;
      }
    });
  }