MEN Lab: URL Shortener

Have you ever wondered how URL shorteners work? In today's lab, you'll build your own bit.ly clone.

Here's the basic idea:

When a user submits a link to your application, you generate a unique, short hash, and store both in the database. When the short URL is requested, your application looks up the long URL and redirects the user to the long URL.

Step 1: The DB

Create a db directory with the following files:

connection.js
  connects to mongodb using mongoose
  exports the connection with module.exports

models.js
  requires the connection file
  defines a Url schema with the following attributes:
    - short
    - long
    - timestamp
  creates a mongoose model from that schema
  exports the Url model

seeds.js
  requires the models file
  creates a few Urls with fake long and short attributes

You did the above correctly if you can seed the database node db/seeds.js

Step 2: The Redirect

Create an index.js file to be the server for your application.

This file should:

require and instantiate express
require the Url model
create a route app.get('/:short') that:
- finds one Url based on req.params.short
- redirects to that url's long attribute

Step 3: The Shortening

Create a POST route for creating new Urls. When a Url is created, redirect to that Url's show page.

When creating a Url, you can use the checksum module to generate the short url.

Here's a demo:

$ npm install --save checksum

var checksum = require("checksum")
checksum("areallylongstring") // '8419ef571ef6d28c9a9e820e70c2defd23b7d948'
checksum("areallylongstring").substr(0,5) // '8419e'

Remember to:

create a route for the show page
set the view engine
- app.set('view engine','hbs')
add a view for the show page, and render it
require and configure the body parser
- app.use(bodyParse.urlencoded({extended: true}))

Step 4: Finish URL Crud

Allow users to view all urls
Allow users to delete Urls
Allow users to edit Urls

Bonus 1

Allow users to customize the short URL, and prevent duplicate entries.

Bonus 2

Allow users to unshorten a URL to see what it would resolve to before redirecting

Bonus 3

Track clicks on the short URL.

chrisjaff / men-lab-url-shortener