Creating an express server

First

Create your Hello-World-Server directory and enter it mkdir Hello-World-Server cd Hello-World-Server

Starting a Node project

Run npm init at the root of your project It should look like this: Just keep pressing enter, edit fields as you feel necessary

package.json

cat package.json

It should look like this:

{
  "name": "hello-world-server",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "repository": {
    "type": "git",
    "url": "git+https://github.com/Purdue-ACM-SIGAPP/hello-world-server.git"
  },
  "author": "",
  "license": "ISC",
  "bugs": {
    "url": "https://github.com/Purdue-ACM-SIGAPP/hello-world-server/issues"
  },
  "homepage": "https://github.com/Purdue-ACM-SIGAPP/hello-world-server#readme"
}

Install express

npm i -S express

Create your first server!

Create file Hello-world-Server/index.js and add the following:

var express = require('express')

var app = express();

app.get('/', function(req, res) {
  res.send('Hello, World')
});

app.listen(3000, function() {
  console.log('Listening on port 3000');
});
module.exports = app;

Run your server!

run node index.js at the root of the project (Hello-World-Server/)

Check it out in your favorite browser at localhost:3000

Creating a router

Create an app directory, and place a routes directory inside of it. mkdir -p app/routes

Add the following to this new index.js file:

var express = require('express');

var router = express.Router();

router.get('/', function(req, res) {
  res.send('Hey, I am the root route');
});

router.get('/message', function(req, res) {
  res.send('You asked for a message, so now you have got one!');
});

module.exports = router;

This is a router, which will specify what our server should be returning to a user when they ask for certain routes. In this example, if they request /, it will return the string Hello, World and if they request /message, it will return You asked for a message, so now you have got one!.

Modify Hello-World-Server/index.js

Now we will add this new router to our root index.js file.

Note: This should not be the file you were just editing, but the index.js file at the root of your project.

var express = require('express');
var routes = require('./app/routes');
var app = express();

app.use('/', routes)

app.listen(3000, function() {
  console.log('Listening on port 3000');
});
module.exports = app;

Run it!

yet again, run node index.js at the root of the project, and check out your brand new fancy, schmancy routes at localhost:3000 and localhost:3000/messages

Create a Server