adding skip load and authorize behavior - closes #164

lib/cancan/controller_additions.rb

@@ -166,6 +166,52 @@ module CanCan
         cancan_resource_class.add_before_filter(self, :authorize_resource, *args)
       end
 
+      # Skip both the loading and authorization behavior of CanCan for this given controller. This is primarily
+      # useful to skip the behavior of a superclass. You can pass :only and :except options to specify which actions
+      # to skip the effects on. It will apply to all actions by default.
+      #
+      #   class ProjectsController < SomeOtherController
+      #     skip_load_and_authorize_resource :only => :index
+      #   end
+      #
+      # You can also pass the resource name as the first argument to skip that resource.
+      def skip_load_and_authorize_resource(*args)
+        skip_load_resource(*args)
+        skip_authorize_resource(*args)
+      end
+
+      # Skip both the loading behavior of CanCan. This is useful when using +load_and_authorize_resource+ but want to
+      # only do authorization on certain actions. You can pass :only and :except options to specify which actions to
+      # skip the effects on. It will apply to all actions by default.
+      #
+      #   class ProjectsController < ApplicationController
+      #     load_and_authorize_resource
+      #     skip_load_resource :only => :index
+      #   end
+      #
+      # You can also pass the resource name as the first argument to skip that resource.
+      def skip_load_resource(*args)
+        options = args.extract_options!
+        name = args.first
+        cancan_skipper[:load][name] = options
+      end
+
+      # Skip both the authorization behavior of CanCan. This is useful when using +load_and_authorize_resource+ but want to
+      # only do loading on certain actions. You can pass :only and :except options to specify which actions to
+      # skip the effects on. It will apply to all actions by default.
+      #
+      #   class ProjectsController < ApplicationController
+      #     load_and_authorize_resource
+      #     skip_authorize_resource :only => :index
+      #   end
+      #
+      # You can also pass the resource name as the first argument to skip that resource.
+      def skip_authorize_resource(*args)
+        options = args.extract_options!
+        name = args.first
+        cancan_skipper[:authorize][name] = options
+      end
+
       # Add this to a controller to ensure it performs authorization through +authorized+! or +authorize_resource+ call.
       # If neither of these authorization methods are called, a CanCan::AuthorizationNotPerformed exception will be raised.
       # This is normally added to the ApplicationController to ensure all controller actions do authorization.
@@ -209,6 +255,10 @@ module CanCan
           ControllerResource
         end
       end
+
+      def cancan_skipper
+        @_cancan_skipper ||= {:authorize => {}, :load => {}}
+      end
     end
 
     def self.included(base)

lib/cancan/controller_resource.rb

@@ -26,21 +26,38 @@ module CanCan
     end
 
     def load_resource
-      if load_instance?
-        self.resource_instance ||= load_resource_instance
-      elsif load_collection?
-        self.collection_instance ||= load_collection
+      unless skip?(:load)
+        if load_instance?
+          self.resource_instance ||= load_resource_instance
+        elsif load_collection?
+          self.collection_instance ||= load_collection
+        end
       end
     end
 
     def authorize_resource
-      @controller.authorize!(authorization_action, resource_instance || resource_class_with_parent)
+      unless skip?(:authorize)
+        @controller.authorize!(authorization_action, resource_instance || resource_class_with_parent)
+      end
     end
 
     def parent?
       @options.has_key?(:parent) ? @options[:parent] : @name && @name != name_from_controller.to_sym
     end
 
+    def skip?(behavior) # This could probably use some refactoring
+      options = @controller.class.cancan_skipper[behavior][@name]
+      if options.nil?
+        false
+      elsif options == {}
+        true
+      elsif options[:except] && ![options[:except]].flatten.include?(@params[:action].to_sym)
+        true
+      elsif [options[:only]].flatten.include?(@params[:action].to_sym)
+        true
+      end
+    end
+
     protected
 
     def load_resource_instance

spec/cancan/controller_additions_spec.rb

@@ -83,4 +83,34 @@ describe CanCan::ControllerAdditions do
     stub(@controller.class).ancestors { ["InheritedResources::Actions"] }
     @controller.class.cancan_resource_class.should == CanCan::InheritedResource
   end
+
+  it "cancan_skipper should be an empty hash with :authorize and :load options and remember changes" do
+    @controller_class.cancan_skipper.should == {:authorize => {}, :load => {}}
+    @controller_class.cancan_skipper[:load] = true
+    @controller_class.cancan_skipper[:load].should == true
+  end
+
+  it "skip_authorize_resource should add itself to the cancan skipper with given model name and options" do
+    @controller_class.skip_authorize_resource(:project, :only => [:index, :show])
+    @controller_class.cancan_skipper[:authorize][:project].should == {:only => [:index, :show]}
+    @controller_class.skip_authorize_resource(:only => [:index, :show])
+    @controller_class.cancan_skipper[:authorize][nil].should == {:only => [:index, :show]}
+    @controller_class.skip_authorize_resource(:article)
+    @controller_class.cancan_skipper[:authorize][:article].should == {}
+  end
+
+  it "skip_load_resource should add itself to the cancan skipper with given model name and options" do
+    @controller_class.skip_load_resource(:project, :only => [:index, :show])
+    @controller_class.cancan_skipper[:load][:project].should == {:only => [:index, :show]}
+    @controller_class.skip_load_resource(:only => [:index, :show])
+    @controller_class.cancan_skipper[:load][nil].should == {:only => [:index, :show]}
+    @controller_class.skip_load_resource(:article)
+    @controller_class.cancan_skipper[:load][:article].should == {}
+  end
+
+  it "skip_load_and_authore_resource should add itself to the cancan skipper with given model name and options" do
+    @controller_class.skip_load_and_authorize_resource(:project, :only => [:index, :show])
+    @controller_class.cancan_skipper[:load][:project].should == {:only => [:index, :show]}
+    @controller_class.cancan_skipper[:authorize][:project].should == {:only => [:index, :show]}
+  end
 end

spec/cancan/controller_resource_spec.rb

@@ -3,10 +3,12 @@ require "spec_helper"
 describe CanCan::ControllerResource do
   before(:each) do
     @params = HashWithIndifferentAccess.new(:controller => "projects")
-    @controller = Object.new # simple stub for now
+    @controller_class = Class.new
+    @controller = @controller_class.new
     @ability = Ability.new(nil)
     stub(@controller).params { @params }
     stub(@controller).current_ability { @ability }
+    stub(@controller_class).cancan_skipper { {:authorize => {}, :load => {}} }
   end
 
   it "should load the resource into an instance variable if params[:id] is specified" do
@@ -339,4 +341,52 @@ describe CanCan::ControllerResource do
       CanCan::ControllerResource.new(@controller, :nested => :project)
     }.should raise_error(CanCan::ImplementationRemoved)
   end
+
+  it "should skip resource behavior for :only actions in array" do
+    stub(@controller_class).cancan_skipper { {:load => {nil => {:only => [:index, :show]}}} }
+    @params.merge!(:action => "index")
+    CanCan::ControllerResource.new(@controller).skip?(:load).should be_true
+    CanCan::ControllerResource.new(@controller, :some_resource).skip?(:load).should be_false
+    @params.merge!(:action => "show")
+    CanCan::ControllerResource.new(@controller).skip?(:load).should be_true
+    @params.merge!(:action => "other_action")
+    CanCan::ControllerResource.new(@controller).skip?(:load).should be_false
+  end
+
+  it "should skip resource behavior for :only one action on resource" do
+    stub(@controller_class).cancan_skipper { {:authorize => {:project => {:only => :index}}} }
+    @params.merge!(:action => "index")
+    CanCan::ControllerResource.new(@controller).skip?(:authorize).should be_false
+    CanCan::ControllerResource.new(@controller, :project).skip?(:authorize).should be_true
+    @params.merge!(:action => "other_action")
+    CanCan::ControllerResource.new(@controller, :project).skip?(:authorize).should be_false
+  end
+
+  it "should skip resource behavior :except actions in array" do
+    stub(@controller_class).cancan_skipper { {:load => {nil => {:except => [:index, :show]}}} }
+    @params.merge!(:action => "index")
+    CanCan::ControllerResource.new(@controller).skip?(:load).should be_false
+    @params.merge!(:action => "show")
+    CanCan::ControllerResource.new(@controller).skip?(:load).should be_false
+    @params.merge!(:action => "other_action")
+    CanCan::ControllerResource.new(@controller).skip?(:load).should be_true
+    CanCan::ControllerResource.new(@controller, :some_resource).skip?(:load).should be_false
+  end
+
+  it "should skip resource behavior :except one action on resource" do
+    stub(@controller_class).cancan_skipper { {:authorize => {:project => {:except => :index}}} }
+    @params.merge!(:action => "index")
+    CanCan::ControllerResource.new(@controller, :project).skip?(:authorize).should be_false
+    @params.merge!(:action => "other_action")
+    CanCan::ControllerResource.new(@controller).skip?(:authorize).should be_false
+    CanCan::ControllerResource.new(@controller, :project).skip?(:authorize).should be_true
+  end
+
+  it "should skip loading and authorization" do
+    stub(@controller_class).cancan_skipper { {:authorize => {nil => {}}, :load => {nil => {}}} }
+    @params.merge!(:action => "new")
+    resource = CanCan::ControllerResource.new(@controller)
+    lambda { resource.load_and_authorize_resource }.should_not raise_error
+    @controller.instance_variable_get(:@project).should be_nil
+  end
 end

spec/cancan/inherited_resource_spec.rb

@@ -3,10 +3,12 @@ require "spec_helper"
 describe CanCan::InheritedResource do
   before(:each) do
     @params = HashWithIndifferentAccess.new(:controller => "projects")
-    @controller = Object.new # simple stub for now
+    @controller_class = Class.new
+    @controller = @controller_class.new
     @ability = Ability.new(nil)
     stub(@controller).params { @params }
     stub(@controller).current_ability { @ability }
+    stub(@controller_class).cancan_skipper { {:authorize => {}, :load => {}} }
   end
 
   it "show should load resource through @controller.resource" do