Started on the ExtendedDocument class with features moved to mixins.

Properties got added, they define getters, setters and aliases.
They will also be the base of the new validation system.

lib/couchrest/mixins/properties.rb

@@ -0,0 +1,63 @@
+module CouchRest
+  module Mixins
+    module DocumentProperties
+      
+      def self.included(base)
+        base.extend(ClassMethods)
+      end
+      
+      module ClassMethods
+        # Stores the class properties
+        def properties
+          @@properties ||= []
+        end
+
+        # This is not a thread safe operation, if you have to set new properties at runtime
+        # make sure to use a mutex.
+        def property(name, options={})
+          unless properties.map{|p| p.name}.include?(name.to_s)
+            property = CouchRest::Property.new(name, options.delete(:type), options)
+            create_property_getter(property) 
+            create_property_setter(property) unless property.read_only == true
+            properties << property 
+          end
+        end
+        
+        protected
+          # defines the getter for the property
+          def create_property_getter(property)
+            meth = property.name
+            class_eval <<-EOS
+              def #{meth}
+                self['#{meth}']
+              end
+            EOS
+
+            if property.alias
+              class_eval <<-EOS
+                alias #{property.alias.to_sym} #{meth.to_sym}
+              EOS
+            end
+          end
+
+          # defines the setter for the property
+          def create_property_setter(property)
+            meth = property.name
+            class_eval <<-EOS
+              def #{meth}=(value)
+                self['#{meth}'] = value
+              end
+            EOS
+
+            if property.alias
+              class_eval <<-EOS
+                alias #{property.alias.to_sym}= #{meth.to_sym}=
+              EOS
+            end
+          end
+          
+      end # module ClassMethods
+      
+    end
+  end
+end