previous_url_angular_service

import { Injectable, OnDestroy } from '@angular/core';
import { NavigationEnd, Router, RoutesRecognized } from '@angular/router';
import { filter, pairwise } from 'rxjs/operators';
import { BehaviorSubject } from 'rxjs';
import { Location } from '@angular/common';
import { CommonUtilsService } from './common-utils.service';
import { untilDestroyed } from './until-destroyed';
import { AppConstants } from '../../app.constants';

@Injectable({
    providedIn: 'root'
})
export class RouterEvents implements OnDestroy {
    // save the previous route
    public previousRoutePath = new BehaviorSubject<string>(this.getPreviousRoutePath());

    constructor(
        private router: Router,
        private location: Location,
        private utils: CommonUtilsService
    ) {
        // 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(),
                untilDestroyed(this)
            )
            .subscribe((event: any[]) => {
                this.announcePreviousRoutePath(event[0].urlAfterRedirects);
            });
    }

    announcePreviousRoutePath(path: string) {
        this.setPreviousRoutePath(path);
        this.previousRoutePath.next(path);
    }

    private getPreviousRoutePath(): string {
        const previousRoutePath = sessionStorage.getItem(AppConstants.ROUTER.PREV_URL);
        if (!previousRoutePath) {
            return '';
        }
        console.log('get', this.utils.cryptThis(this.utils.decode(previousRoutePath), 17));
        return this.utils.cryptThis(this.utils.decode(previousRoutePath), 17);
    }

    private setPreviousRoutePath(previousRoutePath: string): void {
        const cryptPreviousRoutePath = this.utils.encode(
            this.utils.cryptThis(previousRoutePath, 17)
        );
        console.log('set', previousRoutePath);
        sessionStorage.setItem(AppConstants.ROUTER.PREV_URL, cryptPreviousRoutePath);
    }

    ngOnDestroy(): void {}
}


add this service in parent component, app.component.ts
constructor(private routerEvents: RouterEvents) {}

and use it in where you redirect after login,
login.component.ts
--> this.router.navigate([this.routeEvents.previousRoutePath.value])