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JavaScript Express Basics (2015) Doing more with Express Where do I go from here?

Christoph Ruepprich
Christoph Ruepprich
2,887 Points
Posted by Christoph Ruepprich
Christoph Ruepprich
2,887 Points

I have seen examples where express.js is used with http. Instead of app.listen(3000), an http server is created. Why?

Example from http://bit.ly/2ktVtIq http://bit.ly/2jCNIAr var express = require('express'); var http = require('http'); var app = express();

app.use(app.router);

app.get('/', function (req, res, next) { console.log(req.socket.server); });

app.server = http.createServer(app); app.server.listen(3000);

What is the purpose of creating app.server?

4 Answers

Michael Liendo
Michael Liendo
15,326 Points
Michael Liendo
Michael Liendo
15,326 Points

good question. The short answer is that Express is "unopinionated" meaning that it doesn't care how you set it up. It's kind of nice because it gives versatility, but as you've noticed, the downside is that it doesn't help in creating a standard. In regards to your specific code, one way to set up express is to use it's build in methods to create the server. I prefer this way because I can bootstrap a server in 4 lines of code:

const express = require('express')
const app = express()
app.get('/',(req,res) => res.send('Hello')
app.listen(3000,() => console.log('express app listening on port 3000')

But someone not completely familiar with express can fall back to using Node built in server module "HTTP" and "HTTPS" to build their server.

Christoph Ruepprich
Christoph Ruepprich
2,887 Points
Christoph Ruepprich
Christoph Ruepprich
2,887 Points

Thanks Michael, but what does http have that express doesn't?

Michael Liendo
Michael Liendo
15,326 Points
Michael Liendo
Michael Liendo
15,326 Points

Nothing. But some prefer less frills so they stick what they learned first/ are more accustomed to using. Another reason why express is so popular, it caters to lots of personal preferences.

Christopher Debove
PLUS
Christopher Debove
Courses Plus Student 18,373 Points
Christopher Debove
Christopher Debove
Courses Plus Student 18,373 Points

For example you could attach a socket server to this http server.

Express is built on top of an http server. But what if you would like to manipulate the server itself?