gistfile1.txt

module SeoContentable                                                                                                                                                                                                                                                          
  extend ActiveSupport::Concern                                                                                                                                                                                                                                                
                                                                                                                                                                                                                                                                               
  included do                                                                                                                                                                                                                                                                  
    SeoContent.add_seo_contentable_type(self.name) # Register class name                                                                                                                                                                                                       
  end                                                                                                                                                                                                                                                                          
                                                                                                                                                                                                                                                                               
  # Public: Find the SeoContent based on the current class.name and id.                                                                                                                                                                                                        
  #                                                                                                                                                                                                                                                                            
  # Returns an SeoContent or nil.                                                                                                                                                                                                                                              
  def seo_content                                                                                                                                                                                                                                                              
    @seo_content ||= SeoContent.                                                                                                                                                                                                                                               
      find_by_seo_contentable_type_and_seo_contentable_id(self.class.name, self.id)                                                                                                                                                                                            
  end                                                                                                                                                                                                                                                                          
end

# Model
class SeoContent < ActiveRecord::Base                                                                                                                                                                                                                                          
  @@contentable_types = []                                                                                                                                                                                                                                                     
                                                                                                                                                                                                                                                                               
  def self.add_seo_contentable_type(add_seo_contentable_type)                                                                                                                                                                                                                  
    @@contentable_types << add_seo_contentable_type unless @@contentable_types.include?(add_seo_contentable_type)                                                                                                                                                              
  end                                                                                                                                                                                                                                                                          
                                                                                                                                                                                                                                                                               
  def self.seo_contentable_types                                                                                                                                                                                                                                               
    @@contentable_types                                                                                                                                                                                                                                                        
  end                                                                                                                                                                                                                                                                          
end 

class AnyClass
  include SeoContentable
end