add JsonObject type to facilitate storing object serialized in json t…

…o/from couch

adapters/dm-couchdb-adapter/Manifest.txt

@@ -5,6 +5,7 @@ README.txt
 Rakefile
 TODO
 lib/couchdb_adapter.rb
+lib/couchdb_adapter/json_object.rb
 lib/couchdb_adapter/version.rb
 lib/couchdb_adapter/view.rb
 spec/couchdb_adapter_spec.rb

adapters/dm-couchdb-adapter/lib/couchdb_adapter.rb

@@ -6,6 +6,7 @@
 require 'net/http'
 require 'pathname'
 require 'uri'
+require Pathname(__FILE__).dirname + 'couchdb_adapter/json_object'
 require Pathname(__FILE__).dirname + 'couchdb_adapter/view'
 
 module DataMapper

adapters/dm-couchdb-adapter/lib/couchdb_adapter/json_object.rb

@@ -0,0 +1,35 @@
+require 'json'
+
+# Non-lazy objects that serialize to/from JSON, for use with couchdb
+module DataMapper
+  module Types
+    class JsonObject < DataMapper::Type
+      primitive String
+      size 65535
+
+      def self.load(value, property)
+        if value.nil?
+          nil
+        elsif value.is_a?(String)
+          ::JSON.load(value)
+        else
+          raise ArgumentError.new("+value+ must be nil or a String")
+        end
+      end
+
+      def self.dump(value, property)
+        if value.nil?
+          nil
+        elsif value.is_a?(String)
+          value
+        else
+          ::JSON.dump(value)
+        end
+      end
+
+      def self.typecast(value, property)
+        value
+      end
+    end # class JsonObject
+  end # module Types
+end # module DataMapper