switching mongoid over to new adapter

lib/cancan/model_adapters/mongoid_adapter.rb

 module CanCan
-  module Ability
-    # could use alias_method_chain, but it's not worth adding activesupport as a gem dependency
-    alias_method :query_without_mongoid_support, :query
-    def query(action, subject)
-      if defined?(::Mongoid) && subject <= CanCan::MongoidAdditions
-        query_with_mongoid_support(action, subject)
-      else
-        query_without_mongoid_support(action, subject)
+  module ModelAdapters
+    class MongoidAdapter < AbstractAdapter
+      def self.for_class?(model_class)
+        model_class <= CanCan::MongoidAdditions # there should be a better class to detect with this
       end
-    end
-
-    def query_with_mongoid_support(action, subject)
-      MongoidQuery.new(subject, relevant_rules_for_query(action, subject))
-    end
-  end
 
-  class MongoidQuery
-    def initialize(sanitizer, rules)
-      @sanitizer = sanitizer
-      @rules = rules
-    end
+      def database_records
+        @model_class.where(conditions)
+      end
 
-    def conditions
-      if @rules.size == 0
-        false_query
-      else
-        @rules.first.instance_variable_get(:@conditions)
+      def conditions
+        if @rules.size == 0
+          false_query
+        else
+          @rules.first.conditions
+        end
       end
-    end
 
-    def false_query
-      # this query is sure to return no results
-      {:_id => {'$exists' => false, '$type' => 7}}  # type 7 is an ObjectID (default for _id)
+      def false_query
+        # this query is sure to return no results
+        {:_id => {'$exists' => false, '$type' => 7}}  # type 7 is an ObjectID (default for _id)
+      end
     end
   end
 
@@ -62,8 +51,6 @@ module CanCan
     alias_method :matches_conditions_hash?, :matches_conditions_hash_with_mongoid_subject?
   end
 
-
-
   module MongoidAdditions
     module ClassMethods
       # Returns a scope which fetches only the records that the passed ability
@@ -84,8 +71,7 @@ module CanCan
       # Here only the articles which the user can update are returned. This
       # internally uses Ability#conditions method, see that for more information.
       def accessible_by(ability, action = :read)
-        query = ability.query(action, self)
-        where(query.conditions)
+        ability.model_adapter(self, action).database_records
       end
     end
 
@@ -97,6 +83,7 @@ end
 
 # Info on monkeypatching Mongoid :
 # http://log.mazniak.org/post/719062325/monkey-patching-activesupport-concern-and-you#footer
+# This link is now broken, anyone know what it was referring to?
 if defined?(::Mongoid)
   module Mongoid
     module Components

spec/cancan/model_adapters/mongoid_adapter_spec.rb

@@ -37,7 +37,7 @@ if ENV["MODEL_ADAPTER"] == "mongoid"
     config.master = Mongo::Connection.new('127.0.0.1', 27017).db("cancan_mongoid_spec")
   end
 
-  describe CanCan::MongoidAdditions do
+  describe CanCan::ModelAdapters::MongoidAdapter do
     context "Mongoid not defined" do
       before(:all) do
         @mongoid_class = Object.send(:remove_const, :Mongoid)
@@ -46,6 +46,7 @@ if ENV["MODEL_ADAPTER"] == "mongoid"
       after(:all) do
         Object.const_set(:Mongoid, @mongoid_class)
       end
+
       it "should not raise an error for ActiveRecord models" do
         @model_class = Class.new(Project)
         stub(@model_class).scoped { :scoped_stub }
@@ -72,6 +73,12 @@ if ENV["MODEL_ADAPTER"] == "mongoid"
         end.each(&:drop)
       end
 
+      it "should be for only Mongoid classes" do
+        CanCan::ModelAdapters::MongoidAdapter.should_not be_for_class(Object)
+        CanCan::ModelAdapters::MongoidAdapter.should be_for_class(@model_class)
+        CanCan::ModelAdapters::AbstractAdapter.adapter_class(@model_class).should == CanCan::ModelAdapters::MongoidAdapter
+      end
+
       it "should compare properties on mongoid documents with the conditions hash" do
         model = @model_class.new
         @ability.can :read, @model_class, :id => model.id