the new and create actions will now build the resource with attributes based on ability conditions hash - closes #114

lib/cancan/ability.rb

@@ -206,6 +206,14 @@ module CanCan
       message.blank? ? nil : message
     end
 
+    def attributes_for(action, subject)
+      attributes = {}
+      relevant_can_definitions(action, subject).map do |can_definition|
+        attributes.merge!(can_definition.new_attributes) if can_definition.base_behavior
+      end
+      attributes
+    end
+
     private
 
     def unauthorized_message_keys(action, subject)

lib/cancan/can_definition.rb

@@ -67,6 +67,14 @@ module CanCan
       hash
     end
 
+    def new_attributes
+      attributes = {}
+      @conditions.each do |key, value|
+        attributes[key] = value unless [Array, Range, Hash].include? value.class
+      end
+      attributes
+    end
+
     private
 
     def subject_class?(subject)

lib/cancan/controller_resource.rb

@@ -51,7 +51,15 @@ module CanCan
 
     def build_resource
       method_name = @options[:singleton] ? "build_#{name}" : "new"
-      resource_base.send(*[method_name, @params[name]].compact)
+      resource = resource_base.send(*[method_name, @params[name]].compact)
+      initial_attributes.each do |name, value|
+        resource.send("#{name}=", value)
+      end
+      resource
+    end
+
+    def initial_attributes
+      @controller.current_ability.attributes_for(@params[:action].to_sym, resource_class)
     end
 
     def find_resource