add new code type rather than doing hacks based on field name. use code_w_scope instead of code

lib/mongo/query.rb

@@ -16,6 +16,7 @@
 
 require 'mongo/collection'
 require 'mongo/message'
+require 'mongo/types/code'
 
 module XGen
   module Mongo
@@ -70,14 +71,16 @@ module XGen
           self.fields = return_fields
         end
 
-        # Set query selector hash. If sel is a string, it will be used as a
+        # Set query selector hash. If sel is Code/string, it will be used as a
         # $where clause. (See Mongo docs for details.)
         def selector=(sel)
           @selector = case sel
                       when nil
                         {}
-                      when String
+                      when Code
                         {"$where" => sel}
+                      when String
+                        {"$where" => Code.new(sel)}
                       when Hash
                         sel
                       end

lib/mongo/types/code.rb

@@ -0,0 +1,34 @@
+# --
+# Copyright (C) 2008-2009 10gen Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ++
+
+module XGen
+  module Mongo
+    module Driver
+
+      # JavaScript code to be evaluated by MongoDB
+      class Code < String
+        # Hash mapping identifiers to their values
+        attr_accessor :scope
+
+        def initialize(code, scope={})
+          super(code)
+          @scope = scope
+        end
+
+      end
+    end
+  end
+end

lib/mongo/util/bson.rb

@@ -95,9 +95,9 @@ class BSON
   end
 
   def serialize_key_value(k, v)
-      type = bson_type(v, k)
+      type = bson_type(v)
       case type
-      when STRING, CODE, SYMBOL
+      when STRING, SYMBOL
         serialize_string_element(@buf, k, v, type)
       when NUMBER, NUMBER_INT
         serialize_number_element(@buf, k, v, type)
@@ -122,8 +122,7 @@ class BSON
       when UNDEFINED
         serialize_undefined_element(@buf, k)
       when CODE_W_SCOPE
-        # TODO CODE_W_SCOPE unimplemented; may be removed
-        raise "unimplemented type #{type}"
+        serialize_code_w_scope(@buf, k, v)
       else
         raise "unhandled type #{type}"
       end
@@ -198,8 +197,8 @@ class BSON
           key = deserialize_cstr(@buf)
           doc[key] = deserialize_binary_data(@buf)
         when CODE_W_SCOPE
-          # TODO CODE_W_SCOPE unimplemented; may be removed
-          raise "unimplemented type #{type}"
+          key = deserialize_cstr(@buf)
+          doc[key] = deserialize_code_w_scope_data(@buf)
         when EOO
           break
         else
@@ -280,6 +279,24 @@ class BSON
     str
   end
 
+  def deserialize_code_w_scope_data(buf)
+    buf.get_int
+    len = buf.get_int
+    code = buf.get(len)[0..-2]
+    if code.respond_to? "pack"
+      code = code.pack("C*")
+    end
+    if RUBY_VERSION >= '1.9'
+      code.force_encoding("utf-8")
+    end
+
+    scope_size = buf.get_int
+    buf.position -= 4
+    scope = BSON.new().deserialize(buf.get(scope_size))
+
+    Code.new(code, scope)
+  end
+
   def deserialize_oid_data(buf)
     ObjectID.new(buf.get(12))
   end
@@ -416,6 +433,23 @@ class BSON
     buf.position = end_pos
   end
 
+  def serialize_code_w_scope(buf, key, val)
+    buf.put(CODE_W_SCOPE)
+    self.class.serialize_cstr(buf, key)
+
+    # Make a hole for the length
+    len_pos = buf.position
+    buf.put_int(0)
+
+    buf.put_int(val.length + 1)
+    self.class.serialize_cstr(buf, val)
+    buf.put_array(BSON.new.serialize(val.scope).to_a)
+
+    end_pos = buf.position
+    buf.put_int(end_pos - len_pos, len_pos)
+    buf.position = end_pos
+  end
+
   def deserialize_cstr(buf)
     chars = ""
     while true
@@ -429,7 +463,7 @@ class BSON
     chars
   end
 
-  def bson_type(o, key)
+  def bson_type(o)
     case o
     when nil
       NULL
@@ -439,9 +473,10 @@ class BSON
       NUMBER
     when ByteBuffer
       BINARY
+    when Code
+      CODE_W_SCOPE
     when String
-      # magic awful stuff - the DB requires that a where clause is sent as CODE
-      key == "$where" ? CODE : STRING
+      STRING
     when Array
       ARRAY
     when Regexp

lib/mongo/util/xml_to_ruby.rb

@@ -42,8 +42,10 @@ class XMLToRuby
       e.text.to_i
     when 'number'
       e.text.to_f
-    when 'string', 'code'
+    when 'string'
       e.text.to_s
+    when 'code'
+      Code.new (e.text.to_s)
     when 'binary'
       bin = Binary.new
       decoded = Base64.decode64(e.text.to_s)

tests/test_bson.rb

@@ -21,7 +21,7 @@ class BSONTest < Test::Unit::TestCase
   end
 
   def test_code
-    doc = {'$where' => 'this.a.b < this.b'}
+    doc = {'$where' => Code.new('this.a.b < this.b')}
     @b.serialize(doc)
     assert_equal doc, @b.deserialize
   end