[angular] How to determine previous page URL in Angular?

Suppose I am currently on the page which has the URL /user/:id . Now from this page I navigate to next page :id/posts.

Now Is there a way, so that i can check what is the previous URL, i.e. /user/:id.

Below are my routes

export const routes: Routes = [
  { 
    path: 'user/:id', component: UserProfileComponent
  },
  {  
    path: ':id/posts', component: UserPostsComponet 
  }
];

FOR ANGULAR 7+

Actually since Angular 7.2 there is not need to use a service for saving the previous url. You could just use the state object to set the last url before linking to the login page. Here is an example for a login scenario.

@Component({ ... })
class SomePageComponent {
  constructor(private router: Router) {}

  checkLogin() {
    if (!this.auth.loggedIn()) {
      this.router.navigate(['login'], { state: { redirect: this.router.url } });
    }
  }
}

@Component({...})
class LoginComponent {
  constructor(private router: Router) {}

  backToPreviousPage() {
    const { redirect } = window.history.state;

    this.router.navigateByUrl(redirect || '/homepage');
  }
}

Additionally you could also pass the data in the template:

@Component({
  template: '<a routerLink="/some-route" [state]="{ redirect: router.url}">Go to some route</a>'
})
class SomePageComponent {
  constructor(public router: Router) {}
}

This worked for me in angular >= 6.x versions:

this.router.events
            .subscribe((event) => {
              if (event instanceof NavigationStart) {
                window.localStorage.setItem('previousUrl', this.router.url);
              }
            });

All the Above ANSWER will be loads URL multiple times. If user visited any other component also, these code will loads.

So better to use, Service creating concept. https://community.wia.io/d/22-access-the-previous-route-in-your-angular-5-app

This will works well in all versions of Angular. (please Make sure to add it to the providers array in your app.module file! )

Create a injectable service:

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

 /** A router wrapper, adding extra functions. */
@Injectable()
export class RouterExtService {

  private previousUrl: string = undefined;
  private currentUrl: string = undefined;

  constructor(private router : Router) {
    this.currentUrl = this.router.url;
    router.events.subscribe(event => {
      if (event instanceof NavigationEnd) {        
        this.previousUrl = this.currentUrl;
        this.currentUrl = event.url;
      };
    });
  }

  public getPreviousUrl(){
    return this.previousUrl;
  }    
}

Then use it everywhere you need. To store the current variable as soon as possible, it's necessary to use the service in the AppModule.

// AppModule
export class AppModule {
  constructor(private routerExtService: RouterExtService){}

  //...

}

// Using in SomeComponent
export class SomeComponent implements OnInit {

  constructor(private routerExtService: RouterExtService, private location: Location) { } 

  public back(): void {
    this.location.back();
  }

  //Strange name, but it makes sense. Behind the scenes, we are pushing to history the previous url
  public goToPrevious(): void {
    let previous = this.routerExtService.getPreviousUrl();

    if(previous)
      this.routerExtService.router.navigateByUrl(previous);
  }

  //...

}

Pretty simple by using previousNavigation object:

this.router.events
  .pipe(
    filter(e => e instanceof NavigationEnd && this.router.getCurrentNavigation().previousNavigation),
    map(() => this.router.getCurrentNavigation().previousNavigation.finalUrl.toString()),
  )
  .subscribe(previousUrl => {}); 

Angular 6 updated code for getting previous url as string.

import { Router, RoutesRecognized } from '@angular/router';
import { filter, pairwise } from 'rxjs/operators';


export class AppComponent implements OnInit {

    constructor (
        public router: Router
    ) {
    }

    ngOnInit() {
        this.router.events
            .pipe(filter((e: any) => e instanceof RoutesRecognized),
                pairwise()
            ).subscribe((e: any) => {
                console.log(e[0].urlAfterRedirects); // previous url
            });
    }

This simple solution worked for me.

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

export class TempComponent {
    constructor(private router: Router) {
        this.router.events.pairwise().subscribe((event) => {
            console.log(event); // NavigationEnd will have last and current visit url
        });
    };
}

@GünterZöchbauer also you can save it in localstorage but I not prefer it ) better to save in service and get this value from there

 constructor(
        private router: Router
      ) {
        this.router.events
          .subscribe((event) => {
            if (event instanceof NavigationEnd) {
              localStorage.setItem('previousUrl', event.url);
            }
          });
      }

I had similar problem when I had wanted to back to previous page. Solution was easier than I could imagine.

<button [routerLink]="['../']">
   Back
</button>

And it returns to parent url. I hope it will help someone ;)

Maybe all other answers are for angular 2.X.

Now it doesn't work for angular 5.X. I'm working with it.

with only NavigationEnd, you can not get previous url.

because Router works from "NavigationStart", "RoutesRecognized",..., to "NavigationEnd".

You can check with

    router.events.forEach((event) => {
  console.log(event);
});

But still you can not get previous url even with "NavigationStart".

Now you need to use pairwise.

import 'rxjs/add/operator/filter';
import 'rxjs/add/operator/pairwise';

constructor(private router: Router) {
  this.router.events
    .filter(e => e instanceof RoutesRecognized)
    .pairwise()
    .subscribe((event: any[]) => {
      console.log(event[0].urlAfterRedirects);
    });
}
    

With pairwise, You can see what url is from and to.

"RoutesRecognized" is the changing step from origin to target url.

so filter it and get previous url from it.

Last but not least,

put this code in parent component or higher (ex, app.component.ts)

because this code fires after finish routing.

Update angular 6+

The events.filter gives error because filter is not part of events, so change the code to

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

this.router.events
.pipe(filter((evt: any) => evt instanceof RoutesRecognized), pairwise())
.subscribe((events: RoutesRecognized[]) => {
  console.log('previous url', events[0].urlAfterRedirects);
  console.log('current url', events[1].urlAfterRedirects);
});

I'm using Angular 8 and the answer of @franklin-pious solves the problem. In my case, get the previous url inside a subscribe cause some side effects if it's attached with some data in the view.

The workaround I used was to send the previous url as an optional parameter in the route navigation.

this.router.navigate(['/my-previous-route', {previousUrl: 'my-current-route'}])

And to get this value in the component:

this.route.snapshot.paramMap.get('previousUrl')

this.router and this.route are injected inside the constructor of each component and are imported as @angular/router members.

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

Using pairwise from rxjx you can achieve this easier. import { filter,pairwise } from 'rxjs/operators';

previousUrl: string;
constructor(router: Router) {
router.events
  .pipe(filter((evt: any) => evt instanceof RoutesRecognized), pairwise())
  .subscribe((events: RoutesRecognized[]) => {
  console.log('previous url', events[0].urlAfterRedirects);
  console.log('current url', events[1].urlAfterRedirects);
  this.previousUrl = events[0].urlAfterRedirects;
});

}

I had some struggle to access the previous url inside a guard.
Without implementing a custom solution, this one is working for me.

public constructor(private readonly router: Router) {
};

public ngOnInit() {
   this.router.getCurrentNavigation().previousNavigation.initialUrl.toString();
}

The initial url will be the previous url page.

You can use Location as mentioned here.

Here's my code if the link opened on new tab

navBack() {
    let cur_path = this.location.path();
    this.location.back();
    if (cur_path === this.location.path())
     this.router.navigate(['/default-route']);    
  }

Required imports

import { Router } from '@angular/router';
import { Location } from '@angular/common';

Angular 8 & rxjs 6 in 2019 version

I would like to share the solution based on others great solutions.

First make a service to listen for routes changes and save the last previous route in a Behavior Subject, then provide this service in the main app.component in constructor then use this service to get the previous route you want when ever you want.

use case: you want to redirect the user to an advertise page then auto redirect him/her to where he did came from so you need the last previous route to do so.

// service : route-events.service.ts

import { Injectable } from '@angular/core';
import { Router, RoutesRecognized } from '@angular/router';
import { BehaviorSubject } from 'rxjs';
import { filter, pairwise } from 'rxjs/operators';
import { Location } from '@angular/common';

@Injectable()
export class RouteEventsService {

    // save the previous route
  public previousRoutePath = new BehaviorSubject<string>('');

  constructor(
    private router: Router,
    private location: Location
  ) {

    // ..initial prvious route will be the current path for now
    this.previousRoutePath.next(this.location.path());


    // on every route change take the two events of two routes changed(using pairwise)
    // and save the old one in a behavious subject to access it in another component
    // we can use if another component like intro-advertise need the previous route
    // because he need to redirect the user to where he did came from.
    this.router.events.pipe(
      filter(e => e instanceof RoutesRecognized),
      pairwise(),
        )
    .subscribe((event: any[]) => {
        this.previousRoutePath.next(event[0].urlAfterRedirects);
    });

  }
}

provide the service in app.module

  providers: [
    ....
    RouteEventsService,
    ....
  ]

Inject it in app.component

  constructor(
    private routeEventsService: RouteEventsService
  )

finally use the saved previous route in the component you want

  onSkipHandler(){
    // navigate the user to where he did came from
    this.router.navigate([this.routeEventsService.previousRoutePath.value]);
  }