Ruby on Rails Crash Course

Girl Develop It

Instructor: Cecy Correa

Modified from GDI Seattle Ruby on Rails track.

Ruby review!

  • Puts
  • Variables
  • gets.chomp
  • Arrays
  • Hashes
  • Classes
  • Sub-classes

Rails!

Rails

  • Most well-known Ruby gem!
  • Invented by DHH
  • Came out in 2005
  • By 2006, it was already powering Twitter
  • Used by companies like Groupon, Funny or Die, Hulu, Airbnb...

Developing with Rails

You can use Cloud9 or Rails "locally" if you already have it installed.

If you're going to use Cloud9, go ahead and sign up for an account.

Create a new rails app


	rails new app

You just created a new Rails app called "app".

You can call it whatever you want!


	rails new bananas

^^That creates a new Rails app called "bananas"

We're done. Go home.

Let's look at the app.

Rails

Overwhelmed?

There's a lot in a Rails app, let's break it down

Convention over configuration

The reason Rails got so popular is for "convention over configuration." Rails already comes "pre-configured" with a lot of stuff so you don't have to spend time doing set-up.

This means you have to follow convention.

Good news! There's a lot of documentation and resources.

Convention over configuration

The downside is — you have to be careful with what you do / move.

For example, you wouldn't want to delete a folder you don't think you're going to use.

Let's look at the app again

Rails

What you need to know

For now, you really only want to be concerned with:

  • app folder
  • config folder
  • db folder

App folder

The app folder contains, well, the most important elements of your app!

  • Models folder
  • Views folder
  • Controllers folder

More on this later!

This is where you'll spend most of your time in

Config folder

The config folder is good for:

  • Setting up for database (only have to do it once, it's super easy!)
  • Setting up "routes" to direct traffic. (More on this later!)

DB folder

Your Rails app is going to need a database to run and store info.

The db folder will have all of the elements of your database.

Let's take a look!

Model-View-Controller

Also known as MVC

MVC

MVC

Model: the brains (like a class!)

Controller: dispatcher

View: what the user sees

MVC as a recipe

Model: ingredients of a recipe

Controller: directions of a recipe

View: picture of a recipe

MVC

"MVC" is a common "pattern" used in programming and it's what Rails uses.

The Model, View, and Controller all go hand in hand.

Commands to know


rails generate *something*

This is a generator that comes in Rails that helps create necessary files for you.


rake db:migrate

This is always necessecary to generate a database

Databases

sqlite3: the default database that comes with Rails

postgresql: more widely used in "real world" apps. You will need to install postgres in order to deploy your app.

There is an extra step with postgres when creating a database. You need to run rake db:create before rake db:migrate

Starting your Rails app

First steps:

  1. Create a Model
  2. Create a Migration
  3. Run the Migration

Likely you will only do these during project setup.

Starting your Rails app

Ongoing steps:

i.e. you will do these more than once over the course of development:

  1. Generate a Controller
  2. Write methods in your Controller
  3. Generate corresponding Views
  4. Create routes

Let's start coding!

Demo creating a Rails app!

Notes here!

Mind blown.

CRUD

What we just built is called "CRUD"

CREATE

READ

UPDATE

DELETE

This is the most common type of app.

Types of CRUD apps

Facebook

Twitter

Pinterest

A blog

Pretty much any app needs basic CRUD

What if I told you there is an easier way?

Rails scaffolding


	rails generate scaffold *something*

This command generates:

  • Model
  • Migration
  • Controller (filled in!)
  • Views (filled in!)
  • Routes

So why did we just spend so much time doing everything manually?

Because it's important to know the underlying factors of how things work.

Now you can spend your time being more productive!

Next steps: Gems

Gems

Gems are "packages" in Ruby that do things for you.

There are a lot of gems you can take advantage of.

This is great when you're learning! You can see the gem's source code and see how they implemented the feature.

Gems

When choosing a gem, make sure that:

  • The "build" is passing
  • It looks to be recently active
  • Has a fair amount of contributors
  • Is well documented

Adding a gem

Open your "Gemfile" (located at the root of the app)


gem 'name-of-gem'

Usually, the gem documentation will say how to do this

Run 'bundle install' on the command line to install your gems

Resources

Thank you!