Implementing routerLink in New Tab for Angular 6 Applications

Angular Routing Mechanism and Browser Window Operations

In Angular applications, the routerLink directive serves as a core tool for handling internal navigation, managing view transitions within single-page applications through Angular's router. However, when needing to open routes in new browser tabs, the standard routerLink behavior doesn't directly support this functionality, as Angular's routing mechanism was originally designed for no-refresh navigation within the current page.

Limitations of Traditional HTML Approaches

Many developers initially attempt to use HTML's target="_blank" attribute to achieve new tab opening, as shown in the following code:

<a routerLink="/custompage/{{city.id}}" target="_blank">Open</a>

While this approach might work in simple scenarios, it has significant limitations. When Angular applications run in single-page application mode, routerLink intercepts click events and attempts internal navigation through the router, while the target="_blank" attribute may be ignored or produce inconsistent behavior. More importantly, this method cannot fully utilize Angular's URL serialization capabilities, potentially leading to incomplete URL construction or parameter loss.

Best Practice: Combining Router Service with window.open()

The optimal solution based on Angular's routing architecture involves combining the URL building capabilities of the Router service with the browser's window.open() API. The core of this approach lies in using Router.createUrlTree() and Router.serializeUrl() methods to generate complete, serializable URL strings.

First, define a method in the component class to handle new tab opening logic:

import { Component } from '@angular/core';
import { Router } from '@angular/router';

@Component({
  selector: 'app-city-list',
  templateUrl: './city-list.component.html'
})
export class CityListComponent {
  cities = [
    { id: 1, name: 'New York' },
    { id: 2, name: 'London' }
  ];

  constructor(private router: Router) {}

  openCityInNewWindow(cityId: number): void {
    // Create URL tree structure
    const urlTree = this.router.createUrlTree(['/custompage', cityId]);
    
    // Serialize URL tree to string
    const url = this.router.serializeUrl(urlTree);
    
    // Open URL in new tab
    window.open(url, '_blank');
  }
}

In the template, call this method through event binding:

<ul>
  <li *ngFor="let city of cities" (click)="openCityInNewWindow(city.id)">
    {{city.name}}
  </li>
</ul>

Implementation Principle Analysis

The advantage of this method lies in its complete adherence to Angular's routing architecture:

1. URL Construction: The createUrlTree() method creates URL tree objects based on provided route paths and parameters, ensuring proper handling of route parameters, query parameters, and fragments.
2. URL Serialization: serializeUrl() converts URL trees to string format, containing complete routing information that can be directly used for browser navigation.
3. Browser Integration: The window.open() method opens pages in new tabs using serialized URLs while keeping the Angular application state unaffected.

Alternative Approaches Comparison

In addition to the best practice described above, developers can consider the following alternatives:

Simple window.open() Method:

openNewTab(url: string): void {
  window.open(url, '_blank');
}

While straightforward, this approach requires manual URL string construction, is prone to errors, and cannot leverage Angular's routing capabilities.

Traditional Anchor Tags:

<a href="/custompage/{{city.id}}" target="_blank">Open</a>

This method causes complete page reloads, disrupting the single-page application user experience.

Considerations and Best Practices

When implementing new tab navigation, consider the following:

1. Security Considerations: Ensure URLs passed to window.open() come from trusted sources to prevent open redirect vulnerabilities.
2. User Experience: Clearly indicate to users that links will open in new tabs to avoid unexpected navigation.
3. Browser Compatibility: The window.open() method may behave slightly differently across browsers, requiring thorough testing.
4. Angular Version Compatibility: The methods described in this article apply to Angular 2+ versions, including Angular 6 and later.

By combining Angular's Router service with browser APIs, developers can achieve flexible new tab navigation while maintaining the advantages of single-page application architecture. This approach not only addresses the limitations of the target="_blank" attribute but also fully utilizes the powerful capabilities of Angular's routing system, ensuring correct and consistent URL construction.