lennythedev

Your first Web Server with Node and Express in 5 minutes

Build your first Server with Node and Express in 6 steps / 5 minutes
Dec 08, 2019

Originally posted in dev.to

I know, I know... Another Node Express tutorial 😑. But if you still haven't got around to learning Node and building a server, maybe this super-quick tutorial is the one you're waiting for! 😆

Step 1: Install node

Ok, this must take more than 5 minutes, but if you have Node already, skip this and let's go!

Install latest LTS version for your OS

https://nodejs.org/en/download/

To test if it works, create a file server.js in your project root

// server.js
console.log("Hello World!");

And test it out

$ node server.js
Hello world!

Nice! We're ready to do some backend-fu!

Step 2: Setup npm

We use NPM to manage our node packages. Initialize npm and let it take defaults.

$ npm init -y

Step 3: Install and import express middleware

A middleware is a piece of code that has access to the request and response object. For now, think about express making things easier for us by being a "middle-man" 🕵️ between our code and Node's HTTP stuff.

$ npm install express
// server.js
const express = require("express");
const server = express();

Step 4: Add a JSON route handler

Whenever client requests/accesses "/json" (localhost:4000/json), send JSON which is "Hello world" message

// server.js
...
server.get("/json", (req, res) => {
   res.json({ message: "Hello world" });
});

Step 5: Add a HTML route handler

Whenever client requests/accesses "/" (localhost:4000), send file which is an HTML page

__dirname holds the directory of current module (server.js)

// server.js
...
server.get("/", (req, res) => {
   res.sendFile(__dirname + '/index.html');
});

Create index.html in same level as server.js Go to town with the HTML! Or you can copy-paste this if you like blue headings.

<!DOCTYPE html>
<html lang="en">
 <head>
   <title>Node Workshop</title>
 </head>
 <body>
     <h1 style="color: blue;">
        Express: HELLO WORLD
     </h1>
 </body>
</html>

Step 5: Start server

// server.js
...
const port = 4000;

server.listen(port, () => {
    console.log(`Server listening at ${port}`);
});
# CTRL+C to stop server if currently running
$ npm start

Step 6: Test

# on another terminal

$ curl http://localhost:4000/json
{"message":"Hello world"}

$ curl http://localhost:4000
<!-- index.html --> ...

Or open a browser and go to

hackerman

Complete Code

const express = require("express");
const server = express();
const port = 4000;

server.get("/", (req, res) => {
  res.sendFile(__dirname + "/index.html");
});

server.get("/json", (req, res) => {
  res.json({ message: "Hello world" });
});

server.listen(port, () => {
  console.log(`Server listening at ${port}`);
});

"Okay, that was nice. But what can I do with this? "

Add a few more routes and HTML pages and you got yourself an HTML + JSON server!

...
server.get("/items", (req, res) => {
   res.json({ items: [{ "id": 1, "name": "banana" },
                      { "id": 2, "name": "apple" }
                     ]
           });
});

server.get("/info", (req, res) => {
   res.sendFile(__dirname + '/info.html');
});
...

We will need to cover more stuff to

  • build a REST(ful) API Server that implements GET / POST / PUT / DELETE
  • serve templates that accept data (instead of static HTML)
  • much more!

Next up:

Part 2 - REST API with Node and Express

This article is part of a Node+Express series I'm working on.

For the meantime, if you can't get enough of Node+Express 🤓, checkout my Node workshop (Gihub repo and slides):

{% github lenmorld/node_workshop %} Here we discussed:

  • Using Node and Express
  • Routing, request and response
  • Building a REST API
  • Server-rendered templates
  • Connecting to a NoSQL (mongo) database
  • Using external APIs, such as Spotify
  • and much more!

Thanks for reading my first Dev post! Happy server-ing!

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