Rails Polymorphic Association migrations and models, check "console.rb" to see end result

20100220004952_create_posts.rb

# posts migration
# posts are the parent, have many types

class CreatePosts < ActiveRecord::Migration
  def self.up
    create_table :posts do |t|
      t.integer :user_id
      t.references :content, :polymorphic => true       
      t.timestamps
    end
  end

  def self.down
    drop_table :posts
  end
end

20100224150145_create_quotes.rb

# quotes migration
# quotes are a type of post

class CreateQuotes < ActiveRecord::Migration
  def self.up
    create_table :quotes do |t|
      t.string :text
      t.timestamps
    end
  end

  def self.down
    drop_table :quotes
  end
end

20100227220831_create_schedules.rb

# schedule migration
# schedules are a type of post

class CreateSchedules < ActiveRecord::Migration
  def self.up
    create_table :schedules do |t|
      t.datetime :date
      t.string :title
      t.string :location
      t.string :description

      t.timestamps
    end
  end

  def self.down
    drop_table :schedules
  end
end

console.rb

# showing how the association works through console

:: script/console
Loading development environment (Rails 2.3.4)

>> p = Post.find(:all)
=> [#<Post id: 1, user_id: 1, featured: true, content_id: 1, content_type: "Quote", created_at: nil, updated_at: nil>, #<Post id: 3, user_id: 1, featured: true, content_id: 1, content_type: "Schedule", created_at: nil, updated_at: nil>]

>> for post in p
>> puts post.display_content
>> end
<h2>This is a quote</h2>
<p>Fort Collins Bumbling Bees<br />Fort Collins High School at 2010-02-25 21:00:00 UTC<br />Description</p>

post.rb

# post model

class Post < ActiveRecord::Base  
  belongs_to :user
  belongs_to :content, :polymorphic => true

  def display_content
    return self.content.display_content
  end
end

quote.rb

# quotes model

class Quote < ActiveRecord::Base  
  has_one :post, :as => :content

  def display_content
    return ["<h2>", self.text, "</h2>"].join('')
  end
  
end

schedule.rb

# schedule model

class Schedule < ActiveRecord::Base
  has_one :post, :as => :content
  
  def display_content
     return [
        '<p>', self.title,
        '<br />', self.location, " at ", self.date,
        '<br />', self.description,
        '</p>'
      ].join('')
  end
end

schema.rb

# showing the generated tables
# note "content_type" and "content_id" created from "t.references" in the posts migration
# also, this is auto generated on migration

  create_table "posts", :force => true do |t|
    t.integer  "user_id"
    t.boolean  "featured"
    t.integer  "content_id"
    t.string   "content_type"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "quotes", :force => true do |t|
    t.string   "text"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "schedules", :force => true do |t|
    t.datetime "date"
    t.string   "title"
    t.string   "location"
    t.string   "description"
    t.datetime "created_at"
    t.datetime "updated_at"
  end