Written by Jan Kaiponen
on November 30, 2020

Express JS Crash Course

Started to watch the video again. This time working through the examples.

Basic Server Syntax

const express = require('express);

// init express
const app = express();

// create your endpoints / route handlers
app.get('/', function (req, res) {
    // fetch from database...
    // load pages ...
    // return JSON ...
    // full access to request & response
    res.send('Hello World!');
});

// listen on a port
app.listen(5000);

Handling requests

app.get()
app.post()
app.put()
app.delete()

Access to params, query strings, url parts, etc

Express has a router; we can store routes in separate files and export

Can parse incoming data with the body parser

Middleware

Functions that have access to the request and response object.

“A stack of functions that executes when a request is made to the server”

Execute any code
Make changes to the request/response objects
End response cycle
Call next middleware in the stack

Creating a new app

npm init -y

npm i express

Main entry point to the app

index.js

dotenv

Use dotenv for configuration management (REST api tutorial)

const express = require('express')
const app = express();
require('dotenv').config()

.env KEY=VALUE

nodemon

This will watch source files and restart the server when needed.

npm i --save-dev nodemon

package.json

  "scripts": {
    "devStart": "nodemon server.js"
  },

npm run devStart

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