Getting Started

Good tools make application development quicker and easier to maintain than if you did everything by hand.

The Angular CLI is a command line interface tool that can create a project, add files, and perform a variety of ongoing development tasks such as testing, bundling, and deployment.

The goal in this guide is to build and run a simple Angular application in TypeScript, using the Angular CLI while adhering to the Style Guide recommendations that benefit every Angular project.

By the end of the chapter, you'll have a basic understanding of development with the CLI and a foundation for both these documentation samples and for real world applications.

And you can also download the example.

Step 1. Set up the Development Environment

You need to set up your development environment before you can do anything.

Install Node.js® and npm if they are not already on your machine.

Verify that you are running at least Node.js version 8.x or greater and npm version 5.x or greater by running node -v and npm -v in a terminal/console window. Older versions produce errors, but newer versions are fine.

Then install the Angular CLI globally.

npm install -g @angular/cli

Step 2. Create a new project

Open a terminal window.

Generate a new project and default app by running the following command:

ng new my-app

The Angular CLI installs the necessary npm packages, creates the project files, and populates the project with a simple default app. This can take some time.

You can add pre-packaged functionality to a new project by using the ng add command. The ng add command transforms a project by applying the schematics in the specified package. For more information, see the Angular CLI documentation.

Angular Material provides schematics for typical app layouts. See the Angular Material documentation for details.

Step 3: Serve the application

Go to the project directory and launch the server.

cd my-app
  ng serve --open

The ng serve command launches the server, watches your files, and rebuilds the app as you make changes to those files.

Using the --open (or just -o) option will automatically open your browser on http://localhost:4200/.

Your app greets you with a message:

Step 4: Edit your first Angular component

The CLI created the first Angular component for you. This is the root component and it is named app-root. You can find it in ./src/app/app.component.ts.

Open the component file and change the title property from 'app' to 'My First Angular App!'.

export class AppComponent {
  title = 'My First Angular App!';
}

The browser reloads automatically with the revised title. That's nice, but it could look better.

Open src/app/app.component.css and give the component some style.

h1 {
  color: #369;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 250%;
}

Looking good!

What's next?

That's about all you'd expect to do in a "Hello, World" app.

You're ready to take the Tour of Heroes Tutorial and build a small application that demonstrates the great things you can build with Angular.

Or you can stick around a bit longer to learn about the files in your brand new project.

Project file review

An Angular CLI project is the foundation for both quick experiments and enterprise solutions.

The first file you should check out is README.md. It has some basic information on how to use CLI commands. Whenever you want to know more about how Angular CLI works make sure to visit the Angular CLI repository and Wiki.

Some of the generated files might be unfamiliar to you.

The src folder

Your app lives in the src folder. All Angular components, templates, styles, images, and anything else your app needs go here. Any files outside of this folder are meant to support building your app.

src
  app
    app.component.css
    app.component.html
    app.component.spec.ts
    app.component.ts
    app.module.ts
  assets
    .gitkeep
  environments
    environment.prod.ts
    environment.ts
  browserslist
  favicon.ico
  index.html
  karma.conf.js
  main.ts
  polyfills.ts
  styles.css
  test.ts
  tsconfig.app.json
  tsconfig.spec.json
  tslint.json

File	Purpose
app/app.component.{ts,html,css,spec.ts}	Defines the AppComponent along with an HTML template, CSS stylesheet, and a unit test. It is the root component of what will become a tree of nested components as the application evolves.
app/app.module.ts	Defines AppModule, the root module that tells Angular how to assemble the application. Right now it declares only the AppComponent. Soon there will be more components to declare.
assets/*	A folder where you can put images and anything else to be copied wholesale when you build your application.
environments/*	This folder contains one file for each of your destination environments, each exporting simple configuration variables to use in your application. The files are replaced on-the-fly when you build your app. You might use a different API endpoint for development than you do for production or maybe different analytics tokens. You might even use some mock services. Either way, the CLI has you covered.
browserslist	A configuration file to share target browsers between different front-end tools.
favicon.ico	Every site wants to look good on the bookmark bar. Get started with your very own Angular icon.
index.html	The main HTML page that is served when someone visits your site. Most of the time you'll never need to edit it. The CLI automatically adds all js and css files when building your app so you never need to add any <script> or <link> tags here manually.
karma.conf.js	Unit test configuration for the Karma test runner, used when running ng test.
main.ts	The main entry point for your app. Compiles the application with the JIT compiler and bootstraps the application's root module (AppModule) to run in the browser. You can also use the AOT compiler without changing any code by appending the--aot flag to the ng build and ng serve commands.
polyfills.ts	Different browsers have different levels of support of the web standards. Polyfills help normalize those differences. You should be pretty safe with core-js and zone.js, but be sure to check out the Browser Support guide for more information.
styles.css	Your global styles go here. Most of the time you'll want to have local styles in your components for easier maintenance, but styles that affect all of your app need to be in a central place.
test.ts	This is the main entry point for your unit tests. It has some custom configuration that might be unfamiliar, but it's not something you'll need to edit.
tsconfig.{app|spec}.json	TypeScript compiler configuration for the Angular app (tsconfig.app.json) and for the unit tests (tsconfig.spec.json).
tslint.json	Additional Linting configuration for TSLint together with Codelyzer, used when running ng lint. Linting helps keep your code style consistent.

The root folder

The src/ folder is just one of the items inside the project's root folder. Other files help you build, test, maintain, document, and deploy the app. These files go in the root folder next to src/.

my-app
  e2e
    src
      app.e2e-spec.ts
      app.po.ts
    tsconfig.e2e.json
    protractor.conf.js
  node_modules/...
  src/...
    karma.conf.js
  .editorconfig
  .gitignore
  angular.json
  package.json
  README.md
  tsconfig.json
  tslint.json

File	Purpose
e2e/	Inside e2e/ live the end-to-end tests. They shouldn't be inside src/ because e2e tests are really a separate app that just so happens to test your main app. That's also why they have their own tsconfig.e2e.json.
node_modules/	Node.js creates this folder and puts all third party modules listed in package.json inside of it.
.editorconfig	Simple configuration for your editor to make sure everyone that uses your project has the same basic configuration. Most editors support an .editorconfig file. See http://editorconfig.org for more information.
.gitignore	Git configuration to make sure autogenerated files are not committed to source control.
angular.json	Configuration for Angular CLI. In this file you can set several defaults and also configure what files are included when your project is built. Check out the official documentation if you want to know more.
package.json	npm configuration listing the third party packages your project uses. You can also add your own custom scripts here.
protractor.conf.js	End-to-end test configuration for Protractor, used when running ng e2e.
README.md	Basic documentation for your project, pre-filled with CLI command information. Make sure to enhance it with project documentation so that anyone checking out the repo can build your app!
tsconfig.json	TypeScript compiler configuration for your IDE to pick up and give you helpful tooling.
tslint.json	Linting configuration for TSLint together with Codelyzer, used when running ng lint. Linting helps keep your code style consistent.

Next Step

If you're new to Angular, continue with the tutorial. You can skip the "Setup" step since you're already using the Angular CLI setup.