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The Application Shell

Install the Angular CLI

Install the Angular CLI, if you haven't already done so.

npm install -g @angular/cli

Create a new application

Create a new project named angular-tour-of-heroes with this CLI command.

ng new angular-tour-of-heroes

The Angular CLI generated a new project with a default application and supporting files.

Serve the application

Go to the project directory and launch the application.

cd angular-tour-of-heroes
  ng serve --open

The ng serve command builds the app, starts the development server, watches the source files, and rebuilds the app as you make changes to those files.

The --open flag opens a browser to http://localhost:4200/.

You should see the app running in your browser.

Angular components

The page you see is the application shell. The shell is controlled by an Angular component named AppComponent.

Components are the fundamental building blocks of Angular applications. They display data on the screen, listen for user input, and take action based on that input.

Change the application title

Open the project in your favorite editor or IDE and navigate to the src/app folder.

You'll find the implementation of the shell AppComponent distributed over three files:

  1. app.component.ts— the component class code, written in TypeScript.
  2. app.component.html— the component template, written in HTML.
  3. app.component.css— the component's private CSS styles.

Open the component class file (app.component.ts) and change the value of the title property to 'Tour of Heroes'.

app.component.ts (class title property)
title = 'Tour of Heroes';

Open the component template file (app.component.html) and delete the default template generated by the Angular CLI. Replace it with the following line of HTML.

app.component.html (template)
<h1>{{title}}</h1>

The double curly braces are Angular's interpolation binding syntax. This interpolation binding presents the component's title property value inside the HTML header tag.

The browser refreshes and displays the new application title.

Add application styles

Most apps strive for a consistent look across the application. The CLI generated an empty styles.css for this purpose. Put your application-wide styles there.

Here's an excerpt from the styles.css for the Tour of Heroes sample app.

src/styles.css (excerpt)
/* Application-wide Styles */
h1 {
  color: #369;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 250%;
}
h2, h3 {
  color: #444;
  font-family: Arial, Helvetica, sans-serif;
  font-weight: lighter;
}
body {
  margin: 2em;
}
body, input[text], button {
  color: #888;
  font-family: Cambria, Georgia;
}
/* everywhere else */
* {
  font-family: Arial, Helvetica, sans-serif;
}

Final code review

The source code for this tutorial and the complete Tour of Heroes global styles are available in the live example.

Here are the code files discussed on this page.

src/app/app.component.ts
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  title = 'Tour of Heroes';
}
src/app/app.component.html
<h1>{{title}}</h1>
src/styles.css (excerpt)
/* Application-wide Styles */
h1 {
  color: #369;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 250%;
}
h2, h3 {
  color: #444;
  font-family: Arial, Helvetica, sans-serif;
  font-weight: lighter;
}
body {
  margin: 2em;
}
body, input[text], button {
  color: #888;
  font-family: Cambria, Georgia;
}
/* everywhere else */
* {
  font-family: Arial, Helvetica, sans-serif;
}

Summary

  • You created the initial application structure using the Angular CLI.
  • You learned that Angular components display data.
  • You used the double curly braces of interpolation to display the app title.

© 2010–2018 Google, Inc.
Licensed under the Creative Commons Attribution License 4.0.
https://angular.io/tutorial/toh-pt0