Angular TypeScript Tutorial In Visual Studio Code

Edit Using Angular in Visual Studio Code

Angular is a popular web development platform developed and maintained by Google. Angular uses TypeScript as its main programming language. The Visual Studio Code editor supports TypeScript IntelliSense and code navigation out of the box, so you can do Angular development without installing any other extension.

Note: To help get you started with Angular development, you can use the Angular profile template that includes useful extensions, settings, and code snippets.

Welcome to Angular

We'll be using the Angular CLI for this tutorial. To install and use the command line interface as well as run the Angular application server, you'll need the Node.js JavaScript runtime and npm (the Node.js package manager) installed. npm is included with Node.js which you can install from Node.js downloads.

Tip: To test that you have Node.js and npm correctly installed on your machine, you can type node --version and npm --version.

To install the Angular CLI, in a terminal or command prompt type:

npm install -g @angular/cli

This may take a few minutes to install. You can now create a new Angular application by typing:

ng new my-app

my-app is the name of the folder for your application. The ng new command prompts you with options for the generated application. Accept the defaults by pressing the Enter key. This may take a few minutes to create the Angular application in TypeScript and install its dependencies.

Let's quickly run our Angular application by navigating to the new folder and typing ng serve to start the web server and open the application in a browser:

cd my-app ng serve

You should see "Welcome to app!!" on http://localhost:4200 in your browser. We'll leave the web server running while we look at the application with VS Code.

To open your Angular application in VS Code, open another terminal (or command prompt) and navigate to the my-app folder and type code .:

cd my-app code .

Syntax highlighting and bracket matching

Now expand the src\app folder and select the app.component.ts file. You'll notice that VS Code has syntax highlighting for the various source code elements and, if you put the cursor on a parenthesis, the matching bracket is also selected.

IntelliSense

As you hover your mouse over text in the file, you'll see that VS Code gives you information about key items in your source code. Items such as variables, classes and Angular decorators are a few examples where you'll be presented with this information.

As you start typing in app.component.ts, you'll see smart suggestions and code snippets.

You can click the information button (i) to see a flyout with more documentation.

VS Code uses the TypeScript language service for code intelligence (IntelliSense) and it has a feature called Automatic Type Acquisition (ATA). ATA pulls down the npm Type Declaration files (*.d.ts) for the npm modules referenced in the package.json.

Go to Definition, Peek definition

Through the TypeScript language service, VS Code can also provide type definition information in the editor through Go to Definition (F12) or Peek Definition (⌥F12 (Windows Alt+F12, Linux Ctrl+Shift+F10)). Open the app.module.ts file and put the cursor over AppComponent in the bootstrap property declaration, right click and select Peek Definition. A Peek window will open showing the AppComponent definition from app.component.ts.

Press Escape to close the Peek window.

Hello World

Let's update the sample application to "Hello World". Go back to the app.component.ts file and change the title string in AppComponent to "Hello World".

import { Component } from'@angular/core'; @Component({ selector:'app-root', templateUrl:'./app.component.html', styleUrls: ['./app.component.css'] }) exportclassAppComponent { title='Hello World'; }

Once you save the app.component.ts file, the running instance of the server will update the web page and you'll see "Welcome to Hello World!!".

Tip: VS Code supports Auto Save, which by default saves your files after a delay. Check the Auto Save option in the File menu to turn on Auto Save or directly configure the files.autoSave user setting.

Debugging Angular

To debug the client side Angular code, we'll use the built-in JavaScript debugger.

Note: This tutorial assumes you have the Edge browser installed. If you want to debug using Chrome, replace the launch type with chrome. There is also a debugger for the Firefox browser.

Set a breakpoint

To set a breakpoint in app.component.ts, click on the gutter to the left of the line numbers. This will set a breakpoint which will be visible as a red circle.

Configure the debugger

We need to initially configure the debugger. To do so, go to the Run and Debug view (⇧⌘D (Windows, Linux Ctrl+Shift+D)) and select the create a launch.json file link to create a launch.json debugger configuration file. Choose Web App (Edge) from the Select debugger dropdown list. This will create a launch.json file in a new .vscode folder in your project which includes a configuration to launch the website.

We need to make one change for our example: change the port of the url from 8080 to 4200. Your launch.json should look like this:

{ "version": "0.2.0", "configurations": [ { "type": "msedge", "request": "launch", "name": "Launch Edge against localhost", "url": "http://localhost:4200", "webRoot": "${workspaceFolder}" } ] }

Press F5 or the green arrow to launch the debugger and open a new browser instance. The source code where the breakpoint is set runs on startup before the debugger was attached so we won't hit the breakpoint until we refresh the web page. Refresh the page and you should hit your breakpoint.

You can step through your source code (F10), inspect variables such as AppComponent, and see the call stack of the client side Angular application.

For more information about the debugger and its available options, check out our documentation on browser debugging.

Angular profile template

Profiles let you quickly switch your extensions, settings, and UI layout depending on your current project or task. To help you get started with Angular development, you can use the Angular profile template, which is a curated profile with useful extensions and settings. You can use the profile template as is or use it as a starting point to customize further for you own workflows.

You select a profile template through the Profiles > Create Profile... dropdown:

Once you select a profile template, you can review the settings and extensions, and remove individual items if you don't want to include them in your new profile. After creating the new profile based on the template, changes made to settings, extensions, or UI are persisted in your profile.

Popular Starter Kits

In this tutorial, we used the Angular CLI to create a simple Angular application. There are lots of great samples and starter kits available to help build your first Angular application.

Recipes

The VS Code team has created recipes for more complex debugging scenarios. There you'll find the Debugging with Angular CLI recipe which also uses the Angular CLI and goes into detail on debugging the generated project's unit tests.

MEAN Starter

If you'd like to see a full MEAN (MongoDB, Express, Angular, Node.js) stack example, look at MEAN.JS. They have documentation and an application generator for a sample MEAN project. You'll need to install and start MongoDB, but you'll quickly have a MEAN application running. VS Code also has great MongoDB support through the Azure Databases extension.

React

React is a library for building user interfaces and it is more minimal than angular. If you'd like to see an example of React working with VS Code, check out the Using React in VS Code tutorial. It will walk you through creating an React application and configuring the launch.json file for the JavaScript debugger.

Angular Extensions

In addition to the features VS Code provides out of the box, you can install VS Code extensions for greater functionality.

Click on an extension tile above to read the description and reviews on the Marketplace.

To find other Angular extensions, open the Extensions view (⇧⌘X (Windows, Linux Ctrl+Shift+X)) and type 'angular' to see a filtered list of Angular extensions.

The community has also created "Extension Packs" which bundle useful extensions together (for example, a linter, debugger, and snippets) into a single download. To see available Angular extension packs, add the "extension packs" category to your filter (angular @category:"extension packs").

12/11/2024