Nola ON Rails Session 3 Welcome To The Jungle 

Rails.root ● Rails.root is the root of the application directory ● It contains 3 major parts: ○ Logic: app/, lib/, & config/ ○ Tools: Gemfile, Gemfile.lock, Rakefile, config.ru, scripts/, db/ ○ Testing: spec/, test/, features/ ● This is where you run your commands, like `rails` or `rake` 

The app directory ● The app directory is where the important application logic is at ● It normally contains: ○ controllers/ ○ models/ ○ helpers/ ○ mailers/ ○ assets/ ○ views/ ● These will be covered in the following classes 

The config directory ● The config directory is where all of our "setup" code is ● It contains things like: ○ Initializers - Logic that runs at the start of your rails application ○ Environment logic - Logic that runs depending on your environment type ○ Settings - Configurations for various external parts of rails, like databases ● Changing any of these requires a restart of the application 

The lib directory ● The lib directory is a catch all place for the rest of your application logic ● You can put various changes to Rails in here ● These are also loaded at the start of Rails ● You probably wont mess with these 

The Gemfile && Gemfile.lock ● The Gemfile is a list of all the gems you'll be using ● It also groups the gems into specific environments ● It also helps you download the gems you need for your application ● The lock file is simply an organized list of dependencies ● Don't edit it, it's auto generated 

Rakefile ● The Rakefile lets you use the `rake` command ● The `rake -T` command shows you all of the possible tasks ● Run: `rake -T` ● Important rake tasks are: ○ rake routes - Shows a list of routes ○ rake db:migrate - For SQL databases ○ rake db:create - Mostly for SQL databases 

The db directory ● This is where migrations are kept (for sql databases) ● This is also where the schema.rb file is kept (for sql databases) ● The seed.rb file is also here, and that's where we can build up some data 

config.ru ● Largely unimportant for developers, but important for rails ● We'll touch on this later 

The scripts directory ● Here you can keep all sorts of custom scripts that do neat things ● It's also where the default rails script is ● Largely not used, unless you need to do special things for your app 

Testing your rails application ● Testing is the practice of writing checks to make sure your program is working correctly ● There are generally two types of testing practices: ○ Behavior ○ Unit ● There are libraries that have strengths in each: ○ Rspec is good at behavior testing ○ Minitest is good at unit testing ● We will only cover some basics 

Starting the server ● First install dependencies with `bundle install` ● To start your server run: `rails server` ● This starts up a local server for your application ● You can now access the site at http: //localhost:3000 ● No one else can go to this, without you turning some things on ● This is the default page of all rails applications