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## phase 1 # original code from TheRailsWay example class Item < ActiveRecord::Base belongs_to :asset end class Asset < ActiveRecord::Base # all items, incoming and outgoing has_many :items, :dependent => :destroy_all do def incoming @incoming ||= find(:all, :conditions => "base_amount > 0") end def outgoing @outgoing ||= find(:all, :conditions => "base_amount < 0") end end end ## phase 2 # Lets you do this: # # @asset.items.incoming(:all, :order => 'created_at desc', :limit => 15) class Asset < ActiveRecord::Base # all items, incoming and outgoing has_many :items, :dependent => :destroy_all do def incoming(*args) args = [:all] if args.empty? with_scope(:find => { :conditions => 'base_amount > 0'}) { find(*args) } end def outgoing(*args) args = [:all] if args.empty? with_scope(:find => { :conditions => 'base_amount < 0'}) { find(*args) } end end end ## phase 3 # Now the incoming/outgoing methods are on item, so you can do: # # Item.incoming(:all, :order => 'created_at desc', :limit => 15) # # or # # @asset.items.incoming(:all, :order => 'created_at desc', :limit => 15) class Item < ActiveRecord::Base belongs_to :asset def self.incoming(*args) with_scope(:find => { :conditions => 'base_amount > 0'}) { find(*args) } end def self.outgoing(*args) with_scope(:find => { :conditions => 'base_amount < 0'}) { find(*args) } end end class Asset < ActiveRecord::Base has_many :items, :dependent => :destroy_all end

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