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/design_doc.rb

@@ -0,0 +1,63 @@
+require 'digest/md5'
+
+module CouchRest
+  module Mixins
+    module DesignDoc
+      
+      def self.included(base)
+        base.extend(ClassMethods)
+      end
+      
+      module ClassMethods
+        def design_doc_id
+          "_design/#{design_doc_slug}"
+        end
+
+        def design_doc_slug
+          return design_doc_slug_cache if design_doc_slug_cache && design_doc_fresh
+          funcs = []
+          design_doc['views'].each do |name, view|
+            funcs << "#{name}/#{view['map']}#{view['reduce']}"
+          end
+          md5 = Digest::MD5.hexdigest(funcs.sort.join(''))
+          self.design_doc_slug_cache = "#{self.to_s}-#{md5}"
+        end
+
+        def default_design_doc
+          {
+            "language" => "javascript",
+            "views" => {
+              'all' => {
+                'map' => "function(doc) {
+                  if (doc['couchrest-type'] == '#{self.to_s}') {
+                    emit(null,null);
+                  }
+                }"
+              }
+            }
+          }
+        end
+
+        def refresh_design_doc
+          did = design_doc_id
+          saved = database.get(did) rescue nil
+          if saved
+            design_doc['views'].each do |name, view|
+              saved['views'][name] = view
+            end
+            database.save_doc(saved)
+            self.design_doc = saved
+          else
+            design_doc['_id'] = did
+            design_doc.delete('_rev')
+            design_doc.database = database
+            design_doc.save
+          end
+          self.design_doc_fresh = true
+        end
+        
+      end # module ClassMethods
+      
+    end
+  end
+end