moving can definition into ability instance instead of class, this removes ugly instance_exec command

lib/cancan.rb

@@ -2,6 +2,5 @@ module CanCan
   class AccessDenied < StandardError; end
 end
 
-require File.dirname(__FILE__) + '/cancan/instance_exec'
 require File.dirname(__FILE__) + '/cancan/ability'
 require File.dirname(__FILE__) + '/cancan/controller_additions'

lib/cancan/ability.rb

@@ -2,15 +2,8 @@ module CanCan
   module Ability
     attr_accessor :user
     
-    def self.included(base)
-      base.extend ClassMethods
-      base.alias_action :index, :show, :to => :read
-      base.alias_action :new, :to => :create
-      base.alias_action :edit, :to => :update
-    end
-    
     def can?(original_action, target) # TODO this could use some refactoring
-      (self.class.can_history || []).reverse.each do |can_action, can_target, can_block|
+      (@can_history || []).reverse.each do |can_action, can_target, can_block|
         possible_actions_for(original_action).each do |action|
           if (can_action == :manage || can_action == action) && (can_target == :all || can_target == target || target.kind_of?(can_target))
             if can_block.nil?
@@ -20,7 +13,7 @@ module CanCan
               block_args << action if can_action == :manage
               block_args << (target.class == Class ? target : target.class) if can_target == :all
               block_args << (target.class == Class ? nil : target)
-              return instance_exec(*block_args, &can_block)
+              return can_block.call(*block_args)
             end
           end
         end
@@ -30,32 +23,33 @@ module CanCan
     
     def possible_actions_for(initial_action)
       actions = [initial_action]
-      (self.class.aliased_actions || []).each do |target, aliases|
+      (@aliased_actions || default_alias_actions).each do |target, aliases|
         actions += possible_actions_for(target) if aliases.include? initial_action
       end
       actions
     end
       
-    module ClassMethods
+    def can(action, target, &block)
-      attr_reader :can_history
+      @can_history ||= []
-      attr_reader :aliased_actions
+      @can_history << [action, target, block]
+    end
     
-      def can(action, target, &block)
+    def alias_action(*args)
-        @can_history ||= []
+      @aliased_actions ||= default_alias_actions
-        @can_history << [action, target, block]
+      target = args.pop[:to]
-      end
+      @aliased_actions[target] = args
+    end
     
-      def alias_action(*args)
+    def default_alias_actions
-        @aliased_actions ||= {}
+      {
-        target = args.pop[:to]
+        :read => [:index, :show],
-        @aliased_actions[target] = args
+        :create => [:new],
-      end
+        :update => [:edit],
+      }
+    end
     
-      def for_user(user)
+    def prepare(user)
-        ability = new
+      # to be overriden by included class
-        ability.user = user
-        ability
-      end
     end
   end
 end

lib/cancan/controller_additions.rb

@@ -9,7 +9,9 @@ module CanCan
     end
     
     def current_ability
-      ::Ability.for_user(current_user)
+      ability = ::Ability.new
+      ability.prepare(current_user)
+      ability
     end
     
     def can?(*args)

lib/cancan/instance_exec.rb

@@ -1,15 +0,0 @@
-# see http://eigenclass.org/hiki.rb?instance_exec
-class Object
-  module InstanceExecHelper; end
-  include InstanceExecHelper
-  def instance_exec(*args, &block) # !> method redefined; discarding old instance_exec
-    mname = "__instance_exec_#{Thread.current.object_id.abs}_#{object_id.abs}"
-    InstanceExecHelper.module_eval{ define_method(mname, &block) }
-    begin
-      ret = send(mname, *args)
-    ensure
-      InstanceExecHelper.module_eval{ undef_method(mname) } rescue nil
-    end
-    ret
-  end
-end

spec/cancan/ability_spec.rb

@@ -8,7 +8,7 @@ describe CanCan::Ability do
   end
   
   it "should be able to :read anything" do
-    @ability_class.can :read, :all
+    @ability.can :read, :all
     @ability.can?(:read, String).should be_true
     @ability.can?(:read, 123).should be_true
   end
@@ -18,8 +18,8 @@ describe CanCan::Ability do
   end
   
   it "should return what block returns on a can call" do
-    @ability_class.can :read, :all
+    @ability.can :read, :all
-    @ability_class.can :read, Symbol do |sym|
+    @ability.can :read, Symbol do |sym|
       sym
     end
     @ability.can?(:read, Symbol).should be_nil
@@ -27,21 +27,21 @@ describe CanCan::Ability do
   end
   
   it "should pass class with object if :all objects are accepted" do
-    @ability_class.can :preview, :all do |object_class, object|
+    @ability.can :preview, :all do |object_class, object|
       [object_class, object]
     end
     @ability.can?(:preview, 123).should == [Fixnum, 123]
   end
   
   it "should pass class with no object if :all objects are accepted and class is passed directly" do
-    @ability_class.can :preview, :all do |object_class, object|
+    @ability.can :preview, :all do |object_class, object|
       [object_class, object]
     end
     @ability.can?(:preview, Hash).should == [Hash, nil]
   end
   
   it "should pass action and object for global manage actions" do
-    @ability_class.can :manage, Array do |action, object|
+    @ability.can :manage, Array do |action, object|
       [action, object]
     end
     @ability.can?(:stuff, [1, 2]).should == [:stuff, [1, 2]]
@@ -49,8 +49,8 @@ describe CanCan::Ability do
   end
   
   it "should alias update or destroy actions to modify action" do
-    @ability_class.alias_action :update, :destroy, :to => :modify
+    @ability.alias_action :update, :destroy, :to => :modify
-    @ability_class.can :modify, :all do |object_class, object|
+    @ability.can :modify, :all do |object_class, object|
       :modify_called
     end
     @ability.can?(:update, 123).should == :modify_called
@@ -58,7 +58,7 @@ describe CanCan::Ability do
   end
   
   it "should return block result for action, object_class, and object for any action" do
-    @ability_class.can :manage, :all do |action, object_class, object|
+    @ability.can :manage, :all do |action, object_class, object|
       [action, object_class, object]
     end
     @ability.can?(:foo, 123).should == [:foo, Fixnum, 123]
@@ -66,22 +66,19 @@ describe CanCan::Ability do
   end
   
   it "should automatically alias index and show into read calls" do
-    @ability_class.can :read, :all
+    @ability.can :read, :all
     @ability.can?(:index, 123).should be_true
     @ability.can?(:show, 123).should be_true
   end
   
   it "should automatically alias new and edit into create and update respectively" do
-    @ability_class.can(:create, :all) { :create_called }
+    @ability.can(:create, :all) { :create_called }
-    @ability_class.can(:update, :all) { :update_called }
+    @ability.can(:update, :all) { :update_called }
     @ability.can?(:new, 123).should == :create_called
     @ability.can?(:edit, 123).should == :update_called
   end
   
-  it "should be able to access given user" do
+  it "should respond to prepare" do
-    @ability_class.can(:preview, :all) { user }
+    @ability.should respond_to(:prepare)
-    ability = @ability_class.for_user(:some_user)
-    ability.user.should == :some_user
-    ability.can?(:preview, 123).should == :some_user
   end
 end

spec/cancan/controller_additions_spec.rb

@@ -21,7 +21,6 @@ describe CanCan::ControllerAdditions do
   it "should have a current_ability method which generates an ability for the current user" do
     stub(@controller).current_user { :current_user }
     @controller.current_ability.should be_kind_of(Ability)
-    @controller.current_ability.user.should == :current_user
   end
   
   it "should provide a can? method which goes through the current ability" do