[TIL] 20201222 Express Router & Cookies

Router

• An isolated instance of middleware and routes.
• Helps grouping routes into separate files.

express.Router()

• Example

//index.js

const express = require('express');
const app = express();
const shelterRoutes = require('./shelters');

app.use('/shelters', shelterRoutes);

//shelters.js

const express = require('express');
const router = express.Router();

router.get('/', (req, res) => { //'/' is actually '/shelters'
    res.send('All Shelters');
})

router.get('/:id', (req, res) => {
    res.send('One Shelter');
})

module.exports = router;

Express Router & Middleware

• Each router can have its own middleware
• Example

//index.js

//for every route
app.use((req, res, next) => {
    res.send('Middleware?'); 
})



//shelters.js

//for /shelters routes only
router.use((req, res, next) => {
    res.send('Middleware?');
})

 

 

Cookies

• Little bits of information that are stored in a user's browser when browsing a particular website.
• Once a cookie is set, a user's browser will send the cookie on every subsequent request to the site.
• Cookes allow us to make HTTP stateful.
• Acts as a unique identifier

Setting up cookies - Example

//index.js

const express = require('express');
const app = express();

app.get('/setname', (req, res) => {
    res.cookie('name', 'Stevie Chicks');
    res.send('Sent you a cookie!');
})

• Cookies can have many different kinds of values, not just a key-value pair.
• One route can have many cookies.

Cookies Parser Middleware

• install : npm i cookie-parser
• How to use - Example

//index.js

const cookieParser = require('cookie-parser');
app.use(cookieParser());

app.get('/greet', (req, res) => {
    console.log(req.cookies); //prints the cookies
    res.send("Hey There");
})

Signing Cookies

• 'Signing' in programming refers to digital signiture or cryptographic signiture.
• For verifying its integrity, that comething hasn't changed.
• Example - Signing cookies with cookie parser

//index.js

app.use(cookieParser('Thisissecret'));
app.get('/getsignedcookie', (req, res) => {
    res.cookie('fruit', 'grape', {signed: true});
    res.send('Grape?');
})

• Example - Unsigning cookies with cookie parser

//index.js

app.get('/verifycookies', (req, res) => {
    res.send(req.signedCookies); //prints signed cookie
})

 

 

 

 

* This post is a summary of Udemy Course "The Web Developer Bootcamp" by Colt Steele.