Introduction to Routing in Angular

If you create projects with the Angular CLI a base tag will be added by default in index.html, but you’ll want to add it yourself if you’re not using the Angular CLI. All you have to do is add this in the head of the document, before any style or script declaration:

<base href="/">

Next you’ll import RouterModule and Routes in your app module (app.module.ts) and define an array containing your routing configuration. RouterModule imported in the main app module makes the router available everywhere in your app. Also keep in mind that when your app grows you’ll probably want to define the routing configuration in a separate routing module to create better separation of concerns:

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { HttpModule } from '@angular/http';
import { RouterModule, Routes }   from '@angular/router';

import { AppComponent } from './app.component';
import { ProfileComponent } from './profile/profile.component';
import { SettingsComponent } from './settings/settings.component';
import { HomeComponent } from './home/home.component';
const routes: Routes = [
  { path: '', component: HomeComponent },
  { path: 'profile', component: ProfileComponent },
  { path: 'settings', component: SettingsComponent }
];

The app component becomes a shell for your app and takes the <router-outlet> tag where the routing should be rendered. Anchor tags use the routerLink binding instead of the href attribute to point to specific routes. Below is what your app.component.ts would look like.

Notice also the use of the routerLinkActive binding, which will add the given class name to the currently active route, making it easy to style the active link with some CSS:

<nav>
  <a routerLink="/"
     routerLinkActive="active">Home</a>
  <a routerLink="/profile"
     routerLinkActive="active">Profile</a>
  <a routerLink="/settings"
     routerLinkActive="active">Settings</a>
</nav>