[MUSIC]

Hi, I'm Jay and today I'm here to teach you how to write web apps using a Ruby

library called Sinatra.

Ruby is great for writing apps that run on the terminal but

it can run apps that people use from their web browsers too.

You've probably heard of Ruby on Rails, which is Ruby's most popular framework for

writing web apps, but there's a much simpler alternative called Sinatra.

Believe it or not, what you see on the left is code for

a complete Sinatra web app and what we see on the right is its output.

Rails uses a complex software development pattern called model view controller to

generate HTML pages for users.

Sinatra just gives you the request and

lets you generate a response any way you want.

It's a great way to understand what web apps are all about before moving on

to the added complexity of Rails.

We'll start the course by showing you how to install the Sinatra library and

how to create a simple app, then we'll move on to a more complex app,

a wiki, that lets users view text pages you've created.

We'll set up a form that allows users to create their own wiki pages, and

then have our app save those pages to text files.

We'll let users edit or delete existing pages and we'll end by using layout files

with CSS to make the entire site look more appealing.

Ready?

Let's get started.