active_hash_associations_sinatra_example.rb

require 'rubygems'
require 'sinatra'
require 'active_hash'

### HAS_MANY AND BELONGS_TO

module ActiveHash
  class Base
    class << self
      
      def has_many(association_id, options = {})
      
        define_method(association_id) do       
          options = {
            :class_name => association_id.to_s.classify,
            :foreign_key => self.class.to_s.foreign_key
          }.merge(options)
          
          # all needs to be called prior to dynamic finders being available
          options[:class_name].constantize.all
          options[:class_name].constantize.send("find_all_by_#{options[:foreign_key]}", id)
        end
      
      end
    
      def belongs_to(association_id, options = {})
      
        define_method(association_id) do       
          options = {
            :class_name => association_id.to_s.classify,
            :foreign_key => association_id.to_s.foreign_key
          }.merge(options)
          
          options[:class_name].constantize.find(send(options[:foreign_key]))
        end
      
      end
      
    end
  end 
end

### CLASSES

class Country < ActiveHash::Base
  self.data = [
    {:id => 1, :name => "US"},
    {:id => 2, :name => "Canada"}
  ]
  
  has_many :states
  has_many :provinces, :class_name => "State"
  
end

class State < ActiveHash::Base
  self.data = [
    {:id => 1, :name => "California", :country_id => 1},
    {:id => 2, :name => "Alaska", :country_id => 1},
    {:id => 3, :name => "Iowa", :country_id => 1},
    {:id => 4, :name => "British Columbia", :country_id => 2},
    {:id => 5, :name => "Ontario", :country_id => 2}
    ]
    
  belongs_to :country

end


### ACTIONS

get '/has_many' do
  Country.last.provinces.inspect
end

get '/belongs_to' do
  State.last.country.inspect
end