# Express --- - What is express - How to to install it - How to use it - Live Coding!!!!!! --- ## What is express? Express is a minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications. --- ## The install ``` npm install express ``` --- ## Basic Server Setup ``` const express = require('express'); const app = express(); const PORT = 3000; app.listen(PORT, localhost, ()=> { console.log(`Server listening on port ${PORT}`) }) ``` --- ## Usage and Syntax - GET - POST --- ## GET ``` app.get('/route', (req, res)=>{ res.send('Hello World, How is the world today?') // or res.json('Hello World, How is the world today?') }) ``` --- ## POST ``` app.post('/route', (req, res)=>{ res.send({ status: 200, ok: true, msg:'Hello World, How is the world today?' }) }) ``` --- ## Middleware Middleware are functions that have access to the request and response objects. It also has access the the `next()` middleware function *side note: `next()` is used to continue the on the next middleware call in the repsonse-sequence. To learn more about next visit the [using middleware](https://expressjs.com/en/guide/using-middleware.html) section in the express docs.* --- ## Middleware Usage ``` app.use(/*insert middle ware action here*/) ``` --- ## Examples. ``` const express = require('express'); const bodyParser = require("body-parser"); app.use(express.static(__dirname + '/public')); app.use(bodyParser.urlencoded({ extended: false })); app.use(bodyParser.json()); ``` --- # Lets Go Live --- ## Axios ``` https://cdnjs.cloudflare.com/ajax/libs/axios/0.9.1/axios.js ``` --- ## Templating with express ``` npm install express-es6-template-engine ``` --- # Usage ``` const es6Renderer = require('express-es6-template-engine'); app.engine('html', es6Renderer); app.set('views', 'templates'); app.set('view engine', 'html'); app.get('/route', (req,res)=>{ res.render() }) ``` ---