52 lines
1.3 KiB
TypeScript
52 lines
1.3 KiB
TypeScript
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import { Injectable } from '@angular/core';
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import { NavigationEnd, Router } from '@angular/router';
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import { filter } from 'rxjs/operators';
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@Injectable({
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providedIn: 'root',
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})
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export class NavigationService {
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private readonly CURRENT_URL_KEY = 'currentUrl';
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private readonly PREVIOUS_URL_KEY = 'previousUrl';
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currentUrl: string | null;
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previousUrl: string | null;
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constructor(private router: Router) {
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this.currentUrl = sessionStorage.getItem(this.CURRENT_URL_KEY);
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this.previousUrl = sessionStorage.getItem(this.PREVIOUS_URL_KEY);
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this.router.events
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.pipe(filter((event): event is NavigationEnd => event instanceof NavigationEnd))
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.subscribe((event) => {
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const newUrl = event.urlAfterRedirects;
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// Ignore duplicate events
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if (newUrl === this.currentUrl) {
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return;
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}
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this.previousUrl = this.currentUrl;
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this.currentUrl = newUrl;
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if (this.previousUrl) {
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sessionStorage.setItem(this.PREVIOUS_URL_KEY, this.previousUrl);
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}
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sessionStorage.setItem(this.CURRENT_URL_KEY, this.currentUrl);
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});
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}
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canGoBack(): boolean {
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return !!this.previousUrl;
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}
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back(fallbackUrl = '/'): void {
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if (this.canGoBack()) {
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window.history.back();
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} else {
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this.router.navigateByUrl(fallbackUrl);
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}
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}
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}
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