HackTUES 2 Ruby on Rails workshop

Part 1 - Getting comfortable

Introduction

• What is Rails?
• Prerequisites
  • Basic programming knowledge
  • UNIX command line
  • Some HTML, CSS, JS
• The "Google the error message" algorithm

Up and running

• Development environment
• Installing Rails
  • Linux: http://guides.railsgirls.com/install/#setup_for_linux
  • Windows: http://www.railsinstaller.com/
  • Mac: Why are you using one?
• When you are done installing your Rails environment, go try out Ruby

Quick note on scaffolding

• Auto-generated code is overwhelming
• Relying on scaffolding will turn you into a code monkey

First application

• The command line is powerful, don't be afraid!
• Common UNIX commands

Description	Command
list contents	ls
make directory	mkdir
change directory	cd
move file (rename)	mv
copy file	cp
remove file	rm
remove empty directory	rmdir
remove nonempty directory	rm -rf
concatenate & display file contents	cat

• rails new
• Standard directory and file structure

File/Dir	Purpose
app/	Core application (app) code, including models, views, controllers, and helpers
app/assets	Applications assets such as cascading style sheets (CSS), JavaScript files, and images
bin/	Binary executable files
config/	Application configuration
db/	Database files
doc/	Documentation for the application
lib/	Library modules
lib/assets	Library assets such as cascading style sheets (CSS), JavaScript files, and images
log/	Application log files
public/	Data accessible to the public (e.g., via web browsers), such as error pages
bin/rails	A program for generating code, opening console sessions, or starting a local server
test/	Application tests
tmp/	Temporary files
vendor/	Third-party code such as plugins and gems
vendor/assets	Third-party assets such as cascading style sheets (CSS), JavaScript files, and images
README.rdoc	A brief description of the application
Rakefile	Utility tasks available via the rake command
Gemfile	Gem requirements for this app
Gemfile.lock	A list of gems used to ensure that all copies of the app use the same gem versions
config.ru	A configuration file for Rack middleware
.gitignore	Patterns for files that should be ignored by Git

• Bundler
  • Gems are truly outrageous
  • bundle install
  • Gemfile
• rails server
• MVC
  • Architectural pattern
  • Separates internal representation of information from the way the user receives it
  • Interactions
  • Note: HTTP requests
• Hello World!
  • Add a hello action to the Application controller
  • Set the root route

Exercises

• Change the hello action to display a sentence of your choice
• Add a goodbye action that renders "Goodbye, world!" and edit the routes file accordingly

Part 2 - Twitter-style application

Planning

• REST
• Remember note about scaffolding
• rails new
• Models for user and micropost
  • Users - id, name, email
  • Microposts - id, content, user_id

Users resource

• rails generate scaffold
• Migrating our database
• Note: Rake
• MVC in action - let's take a tour
• RESTful routes

HTTP request	URL	Action	Purpose
GET	/users	index	page to list all users
GET	/users/1	show	page to show user with id 1
GET	/users/new	new	page to make a new user
POST	/users	create	create a new user
GET	/users/1/edit	edit	page to edit user with id 1
PATCH	/users/1	update	update user with id 1
DELETE	/users/1	destroy	delete user with id 1

• Weaknesses
• No data validation
• No auth
• No styling
• No real understanding

Microposts resource

• Repeat first steps just like the users resource
• Validations - constraining microposts to 140 characters
• Associations
  • has_many
  • belongs_to

Exercises

• Find out how to validate the presence of micropost content
• When you do, validate the presence of name and email attributes in the User model as well

Conclusion

• Very high-level overview of Rails
• Taste of MVC and REST
• Working simple web app

What next?

• This workshop is based on Chapter 1 & 2 of Michael Hartl's Rails Tutorial
• You can read the whole book to get a great understanding of Rails