MEAN Machine - A beginner's practical guide to the JavaScript stack (2015)

Starting Node

Let’s look at how we can start to build out our Node applications. We’ll go through basic Node configuration, installing npm packages, and creating a simple app.

Configuration (package.json)

Node applications are configured within a file called package.json. You will need a package.json file for each project you create.

This file is where you configure the name of your project, versions, repository, author, and the all important dependencies.

Here is a sample package.json file:

1 {

2 "name": "mean-machine-code",

3 "version": "1.0.0",

4 "description": "The code repository for the book, MEAN Machine.",

5 "main": "server.js",

6 "repository": {

7 "type": "git",

8 "url": "https://github.com/scotch-io/mean-machine-code"

9 },

10 "dependencies": {

11 "express": "latest",

12 "mongoose": "latest"

13 },

14 "author": "Chris Sevilleja & Holly Lloyd",

15 "license": "MIT",

16 "homepage": "https://github.com/scotch-io/mean-machine-code"

17 }

That seems overwhelming at first, but if you take it line by line, you can see that a lot of the attributes created here make it easier for other developers to jump into the project. We’ll look through all these different parts later in the book, but here’s a very simple package.json with only the required parts.

1 {

2 "name": "mean-machine-code",

3 "main": "server.js"

4 }

These are the most basic required attributes.

main tells Node which file to use when we want to start our applications. We’ll name that file server.js for all of our applications and that will be where we start our applications.

For more of the attributes that can be specified in our package.json files, here are the package.json docs.

Initialize Node App

The package.json file is how we will start every application. It can be hard to remember exactly what goes into a package.json file, so npm has created an easy to remember command that let’s you build out your package.json file quickly and easily. That command is npm init.

Let’s create a sample project and test out the npm init command.

1. Create a folder: mkdir awesome-test

2. Jump into that folder: cd awesome-test

3. Start our Node project: npm init

It will give you a few options that you can leave as default or customize as you wish. For now, you can leave everything default except for the main (entry point) file. Ours will be called server.js.

You can see that our new package.json file is built and we have our first Node project!

NPM Init

Since we have a package.json file now, we can go into our command line and type node server.js to start up this Node app! It will just throw an error since we haven’t created the server.js file that we want to use to begin our Node application. Not very encouraging to see an error on our first time starting a Node server! Let’s change that and make an application that does something.

Creating a Very Simple Node App

Open up your package.json file and delete everything except those basic requirements:

1 {

2 "name": "awesome-test",

3 "main": "server.js"

4 }

Now we will need to create the server.js file. The only thing we will do here is console.log out some information. console.log() is the way we dump information to our console. We’re going to use it to send a message when we start up our Node app.

Here is our server.js file’s contents.

1 console.log('ITS MY FIRST NODE APP! OH AND I GUESS HELLO WORLD');

Now we can start up our Node application by going into our command line and typing: node server.js

node server.js

Starting a Node Application

To start a Node application, you just go into the command line and type:

node server.js

server.js is what we defined to be our main file in package.json so that’s the file we will specify when starting. Our server will now be stopped since all we did was console.log(), but in the future, if you would like to stop your Node server, you can just type ‘ctrl c’.