Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

Why do we have install Node.js for Angular 2.0?

I started a tutorial on Angular 2.0, the first step in setting up the workspace is installing Node.js and NPM.

Why do we have install Node.js for Angular 2.0?

I don't remember doing this for angular 1.X.

like image 823
user2572003 Avatar asked May 17 '16 05:05

user2572003


People also ask

Is NodeJS mandatory for Angular 2?

Yes. Node. js required for Angular 2 or Angular apps.

Why do you need NodeJS for installing Angular framework?

you don't need node. js to run your application, but you need node. js to develop your angular app to use necessary tools. NodeJS gives you the tool npm that allows you to download libraries and packages that you use in Angular.

Do I need to install NodeJS for Angular?

However, Angular is a front end technology, so even if you need to install Node. js on your development machine, it is only for running the CLI. Once you build your app for production you won't need Node.

Why do we install npm in AngularJS?

When you run npm install , Node Package Manager, or npm for short, will download those dependencies and put them in node_modules folder. because each angular app might have different dependencies. and dependencies are resolved relative to your angular app.


2 Answers

Technically, Node.js and NPM are not needed to do Angular2 work. It does ease things though. Here's the main reasons I speculate are behind this choice:

  • CLI: Since a while now the de facto way to build and develop new Angular apps is to use the CLI tooling which relies on Node and NPM as well.

  • TypeScript: Examples are .ts, and you need to run a compiler step to get them into .js, which can be done on-the-fly easily with Node.js and NPM (plus it's a way of easily getting typing files);

  • Web Server: Serving your Angular SPA from a "real" albeit light web server prevents probably some nasty issues that come with checking your site using file:// links.

The Quickstart guide itself actually continues to mention some more concrete reasons as well:

Here's what these scripts do:

  • npm start - runs the compiler and a server at the same time, both in "watch mode"

  • npm run tsc - runs the TypeScript compiler once

  • npm run tsc:w - runs the TypeScript compiler in watch mode; the process keeps running, awaiting changes to TypeScript files and re-compiling when it sees them

  • npm run lite - runs the lite-server, a light-weight, static file server with excellent support for Angular apps that use routing

  • npm run typings - runs the typings tool separately

  • npm run postinstall - called by npm automatically after it successfully completes package installation. This script installs the TypeScript definition files defined in typings.json

You can also have a look at the Quickstart source and further dive into where NPM is needed.


Footnote: there's a similar question about needing Node.js for AngularJS (1.x).

like image 52
Jeroen Avatar answered Oct 21 '22 04:10

Jeroen


Because Anglar2 is based on Typescript, Web Components and ES6 which need compilation for performance and broader browser support. Typescript is compiled to ES5 JavaScript and the other features require shims for backwards compatibility.

Since Typescript is a superset of JavaScript, and it's compiled to JavaScript anyway, you can write your code in plain JavaScript but it's not recommended.

For a more detailed explanation check out these videos on YouTube

  • Why Typescript
  • Instalation steps
like image 30
Peter Avatar answered Oct 21 '22 05:10

Peter