'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
}
];
Solution 1:[1]
You can subscribe to route changes and store the current event so you can use it when the next happens
previousUrl: string;
constructor(router: Router) {
router.events
.pipe(filter(event => event instanceof NavigationEnd))
.subscribe((event: NavigationEnd) => {
console.log('prev:', event.url);
this.previousUrl = event.url;
});
}
Solution 2:[2]
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);
});
Solution 3:[3]
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);
}
//...
}
Solution 4:[4]
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
});
}
Solution 5:[5]
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]);
}
Solution 6:[6]
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);
}
});
Solution 7:[7]
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) {}
}
Solution 8:[8]
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';
Solution 9:[9]
@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);
}
});
}
Solution 10:[10]
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';
Solution 11:[11]
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 => {});
Solution 12:[12]
Easiest way
As mentioned here, please simply use Location which come from @angular/common.
Example
In your component.ts
import { Location } from '@angular/common';
@Component({...})
export class AuthenticationComponent {
constructor(private _location: Location) {}
public returnPreviousUrl(): void {
this._location.back();
}
}
In your component.html
<div (click)="returnPreviousUrl()">return</div>
Solution 13:[13]
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.
Solution 14:[14]
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
});
};
}
Solution 15:[15]
import { Router, RoutesRecognized } from '@angular/router';
import { filter, pairwise } from 'rxjs/operators';
constructor(
private router: Router
) {
}
ngOnInit(){
this.router.events
.pipe(filter((evt: any) => evt instanceof RoutesRecognized), pairwise())
.subscribe((events: RoutesRecognized[]) => {
let prevUrl = events[0].urlAfterRedirects;
console.log('previous url', prevUrl);
console.log('current url', events[1].urlAfterRedirects);
});
}
Solution 16:[16]
Reference : Get Previous URL in Angular
Using as part of a service is better approach
@Injectable({
providedIn: 'root'
})
export class RoutingStateService
{
private history = [];
constructor(private router: Router)
{
this.loadRouting();
}
public loadRouting(): void
{
this.router.events
.pipe(filter(event => event instanceof NavigationEnd))
.subscribe(({urlAfterRedirects}: NavigationEnd) => {
this.history = [...this.history, urlAfterRedirects];
});
}
public getHistory(): string[]
{
return this.history;
}
public getPreviousUrl(): string
{
return this.history[this.history.length - 2];
}
}
Next in your component on init
ngOnInit(): void {
this.routingStateService.loadRouting()
}
Now you can get the previous url by calling getPreviousUrl() method from service
Solution 17:[17]
Most up-to-date complete answer including refreshes.
the service
import { Injectable} from '@angular/core';
import { Router, NavigationEnd } from '@angular/router';
import { filter, pairwise } from 'rxjs/operators';
@Injectable()
export class RouterService{
private prevUrl?: any = undefined;
constructor(private router: Router){
router.events.pipe(
filter(e => e instanceof NavigationEnd),
pairwise()
).subscribe(x=>{
this.prevUrl = x[0].urlAfterRedirects;
localStorage.setItem("prevUrl", this.prevUrl);
})
}
public getPrevUrl(){
console.log(this.prevUrl)
return this.prevUrl;
}
public getCurrUrl(){
return this.router.url;
}
public checkStorage(){
console.log("checkign storage")
this.prevUrl= localStorage.getItem("prevUrl")
}
}
app.component
import { RouterService } from './shared/services/router-service';
export class AppComponent {
constructor(private routerSvc: RouterService ) {}
ngOnInit() {
this.routerSvc.checkStorage()
}
}
inlcuse service in App.module
@NgModule({
...
providers: [
RouterService
],
in component
import { RouterService } from '../services/router-service';
export class MyComponent implements OnInit {
constructor(private routerSvc: RouterService) { }
ngOnInit(): void {
console.log(this.routerSvc.getPrevUrl())
}
}
Solution 18:[18]
You can try this sample code:
import {Router, RoutesRecognized, Event} from '@angular/router';
import {filter, pairwise} from 'rxjs/operators';
previousUrl = '';
constructor(
private readonly location: Location, private readonly router: Router) {
this.router.events
.pipe(filter((evt: Event): evt is RoutesRecognized => evt instanceof RoutesRecognized), pairwise())
.subscribe((events: RoutesRecognized[]) => {
this.previousUrl = events[0].urlAfterRedirects;
});
}
Type declaration of 'any' loses type-safety. It's better to provide a more specific type.
TypeScript's any type is a super and subtype of all other types, and allows dereferencing all properties. As such, any is dangerous - it can mask severe programming errors, and its use undermines the value of having static types in the first place.
Solution 19:[19]
There is an issue in the Angular GitHub that's being considered right now that would make this super easy, i.e., Router.previousUrl. Please put your ? on the issue to make it cross the required 20 in order to make it into the backlog:
Solution 20:[20]
You can simply use the solution with RXJX exemple inspiration
app.componennt.html
<p>Previous URL: {{ previousUrl }}</p>
<p>Current URL: {{ currentUrl }}</p>
app.component.ts
previousUrl: string = null
currentUrl: string = null
ngOnInit() {
this.router.events.pipe(
filter((event) => event instanceof NavigationEnd)
).subscribe((event: NavigationEnd) => {
this.previousUrl = this.currentUrl;
this.currentUrl = event.url;
this.urlService.setPreviousUrl(this.previousUrl);
});
}
injector service
import { Injectable } from '@angular/core';
import { BehaviorSubject, Observable, take } from 'rxjs';
@Injectable()
export class UrlService {
private previousUrl: BehaviorSubject<string> = new BehaviorSubject<string>(null);
public previousUrl$: Observable<string> = this.previousUrl.asObservable();
constructor() { }
setPreviousUrl(previousUrl: string) {
this.previousUrl.next(previousUrl);
}
}
wanted.component.ts, just implement previous function to navigate
public goToPrevious(): void {
let obsValue = undefined;
const sub = this.urlService.previousUrl$.pipe(take(1)).subscribe(value => obsValue = value);
sub.unsubscribe();
console.log('url', obsValue)
this.router.navigateByUrl(obsValue)
}
You can also show the in previous value in template with pipe async
other.component.html
<p>Previous URL: {{ previousUrl | async }}</p>
other.component.ts
export class OtherComponent implements OnInit {
previousUrl: Observable<string> = this.urlService.previousUrl$;
constructor(private urlService: UrlService) { }
ngOnInit() {
this.urlService.previousUrl$.subscribe((previousUrl: string) => {
console.log('previous url: ', previousUrl);
});
}
}
Solution 21:[21]
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! )
Sources
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Source: Stack Overflow