1  
   2  ActiveRecord::Base::ClassMethods.class_eval do
   3    # Allows set data it nested way from form for has_one and belongs_to associations
   4    # add <tt>association_data=</tt> method that asset Hash
   5    # Example: <tt>allow_data_update_for :place</tt> to allow saving input fields with names like "organization[place_data][address]"
   6    # Inspired by http://weblog.jamisbuck.org/2007/1/11/moving-associated-creations-to-the-model
   7    def allow_data_update_for(association)
   8      define_method "#{association}_data=" do |data|
   9        if self.send(association)
  10          self.send(association).attributes = data
  11          instance_eval "@update_#{association}_on_save = true"
  12        else
  13          self.send("build_#{association}", data)
  14        end
  15      end
  16      before_update do |obj|
  17        obj.send(association).save if obj.instance_variable_get("@update_#{association}_on_save")
  18      end
  19    end
  20  end