Ruby Rails ON 2 Monday, February 27, 12

About Me Mike Skalnik github.com/skalnik @skalnik Monday, February 27, 12

Where did we stop? We have posts! Monday, February 27, 12

ActiveRecord Associations Monday, February 27, 12

4 Kinds Monday, February 27, 12 has_one, has_many, habtm/has_many :through, belongs_to

has_one Georgia Tech A School Buzz Mascot has_one Monday, February 27, 12

has_one class School < ActiveRecord::Base has_one :mascot end Monday, February 27, 12

has_many id title body 1 First Post! … 2 The Value of… … id author body post_id 1 Mike … 1 2 Eric … 1 3 Kyle … 2 Monday, February 27, 12

has_many class Post < ActiveRecord::Base has_many :comments end Monday, February 27, 12

belongs_to class Comment < ActiveRecord::Base belongs_to :post end Monday, February 27, 12

belongs_to class Mascot < ActiveRecord::Base belongs_to :school end Monday, February 27, 12

has_many :through has_and_belongs_to vs Monday, February 27, 12

expose join table hide join table vs Monday, February 27, 12 Exposed as a model

class Category < ActiveRecord::Base has_many :categorizations has_many :posts, :through => categorizations end class Categorization < ActiveRecord::Base belongs_to :post belongs_to :category end class Post < ActiveRecord::Base has_many :categorizations has_many :categories, :through => categorizations end Monday, February 27, 12 Allows for validations, along with attaching data to the association. How about Users with Ratings & Songs?

vs Monday, February 27, 12

class Post < ActiveRecord::Base has_and_belongs_to_many :categories end class Category < ActiveRecord::Base has_and_belongs_to_many :posts end Monday, February 27, 12 No touching the table, just a link. Still need to write migration though!

Usage @post.comments #=> [#, …] @post.categories #=> [#, …] @comment.post #=> # @school.mascot #=> # Monday, February 27, 12

$ terminal_time Monday, February 27, 12

ActiveRecord Validations ✖ ✓ Monday, February 27, 12 Not a full list, but the more common ones

validates :terms, :acceptance => true Monday, February 27, 12 Accept TOS

validates :password, :confirmation => true Monday, February 27, 12 confirm password

validates :username, :exclusion => { :in => [‘user’] } Monday, February 27, 12 reserved usernames

validates :email, :format => { :with => /.*@.*/ } Monday, February 27, 12 validate email format

validates :size, :inclusion => { :in => [‘small’, …] } Monday, February 27, 12 size is in list

validates :name, :length => { :minimum => 2, :maximum => 500, :in => 2..500, :is => 12 } Monday, February 27, 12 Lots of options

validates :points, :numericality => true Monday, February 27, 12

validates :email, :presence => true Monday, February 27, 12 Ensure it’s there

validates :email, :uniqueness => true Monday, February 27, 12 Ensure they haven’t registered before

Usage @post.save #=> false if not valid @post.valid? Monday, February 27, 12

More Resources Monday, February 27, 12 Not a full list, but the more common ones

RailsGuides http://guides.rubyonrails.org Monday, February 27, 12 Not a full list, but the more common ones

RailsCasts http://railscasts.com Monday, February 27, 12 Not a full list, but the more common ones

Ruby Toolbox http://ruby-toolbox.com Monday, February 27, 12 Not a full list, but the more common ones

Me [email protected] Monday, February 27, 12 Not a full list, but the more common ones

@ Web Tech Innovators Monday, February 27, 12

ATLRUG Monday, February 27, 12

THANKS Monday, February 27, 12