releasing version 1.1, see wiki and changelog for details

CHANGELOG.rdoc

@@ -1,3 +1,26 @@
+1.1.0 (April 17, 2010)
+
+* Supporting arrays, ranges, and nested hashes in ability conditions
+
+* Removing "unauthorized!" method in favor of "authorize!" in controllers
+
+* Adding action, subject and default_message abilities to AccessDenied exception - see issue #40
+
+* Adding caching to current_ability controller method, if you're overriding this be sure to add caching too.
+
+* Adding "accessible_by" method to Active Record for fetching records matching a specific ability
+
+* Adding conditions behavior to Ability#can and fetch with Ability#conditions - see issue #53
+
+* Renaming :class option to :resource for load_and_authorize_resource which now supports a symbol for non models - see issue #45
+
+* Properly handle Admin::AbilitiesController in params[:controller] - see issue #46
+
+* Adding be_able_to RSpec matcher (thanks dchelimsky), requires Ruby 1.8.7 or higher - see issue #54
+
+* Support additional arguments to can? which get passed to the block - see issue #48
+
+
 1.0.2 (Dec 30, 2009)
 
 * Adding clear_aliased_actions to Ability which removes previously defined actions including defaults - see issue #20

README.rdoc

@@ -1,29 +1,26 @@
 = CanCan
 
-RDocs[http://rdoc.info/projects/ryanb/cancan] | Wiki[http://wiki.github.com/ryanb/cancan] | Screencast[http://railscasts.com/episodes/192-authorization-with-cancan] | Metrics[http://getcaliper.com/caliper/project?repo=git%3A%2F%2Fgithub.com%2Fryanb%2Fcancan.git] | Tests[http://runcoderun.com/ryanb/cancan]
+Wiki[http://wiki.github.com/ryanb/cancan] | RDocs[http://rdoc.info/projects/ryanb/cancan] | Screencast[http://railscasts.com/episodes/192-authorization-with-cancan] | Metrics[http://getcaliper.com/caliper/project?repo=git%3A%2F%2Fgithub.com%2Fryanb%2Fcancan.git]
 
-This is a simple authorization solution for Ruby on Rails to restrict what a given user is allowed to access in the application. This is completely decoupled from any role based implementation allowing you to define user roles the way you want. All permissions are stored in a single location for convenience.
+CanCan is an authorization solution for Ruby on Rails. This restricts what a given user is allowed to access throughout the application. It is completely decoupled from any role based implementation and focusses on keeping permission logic in a single location (the +Ability+ class) so it is not duplicated across controllers, views, and database queries.
+
+This assumes you already have authentication (such as Authlogic[http://github.com/binarylogic/authlogic] or Devise[http://github.com/plataformatec/devise]). This will provide a +current_user+ method which CanCan relies on. See {Changing Defaults}[http://wiki.github.com/ryanb/cancan/changing-defaults] if you need different behavior.
 
-This assumes you already have authentication (such as Authlogic[http://github.com/binarylogic/authlogic]) which provides a current_user model.
 
 == Installation
 
-You can set it up as a gem in your environment.rb file.
+CanCan is provided as a gem. Simply include it in your environment.rb or Gemfile.
 
   config.gem "cancan"
 
-And then install the gem.
-
-  sudo rake gems:install
-
-Alternatively you can install it as a Rails plugin.
+Alternatively it can be installed as a plugin.
 
   script/plugin install git://github.com/ryanb/cancan.git
 
 
 == Getting Started
 
-First, define a class called Ability in "models/ability.rb".
+First, define a class called +Ability+ in "models/ability.rb". It should look something like this.
 
   class Ability
     include CanCan::Ability
@@ -39,30 +36,34 @@ First, define a class called Ability in "models/ability.rb".
 
 This is where all permissions will go. See the "Defining Abilities" section below for more information.
 
-You can access the current permissions at any point using the "can?" and "cannot?" methods in the view.
+The current user's permissions can be accessed using the "can?" and "cannot?" methods in the view and controller.
 
   <% if can? :update, @article %>
     <%= link_to "Edit", edit_article_path(@article) %>
   <% end %>
 
-You can also use these methods in a controller along with the "unauthorized!" method to restrict access.
+See {Checking Abilities}[http://wiki.github.com/ryanb/cancan/checking-abilities] for more information
+
+The "authorize!" method in the controller will raise an exception if the user is not able to perform the given action.
 
   def show
     @article = Article.find(params[:id])
-    unauthorized! if cannot? :read, @article
+    authorize! :read, @article
   end
 
-Setting this for every action can be tedious, therefore the load_and_authorize_resource method is also provided to automatically authorize all actions in a RESTful style resource controller. It will set up a before filter which loads the resource into the instance variable and authorizes it.
+Setting this for every action can be tedious, therefore the +load_and_authorize_resource+ method is provided to automatically authorize all actions in a RESTful style resource controller. It will set up a before filter which loads the resource into the instance variable and authorizes it for each action.
 
   class ArticlesController < ApplicationController
     load_and_authorize_resource
     
     def show
-      # @article is already loaded
+      # @article is already loaded and authorized
     end
   end
 
-If the user authorization fails, a CanCan::AccessDenied exception will be raised. You can catch this and modify its behavior in the ApplicationController.
+See {Authorizing Controller Actions}[http://wiki.github.com/ryanb/cancan/authorizing-controller-actions] for more information
+
+If the user authorization fails a CanCan::AccessDenied exception will be raised. You can catch this and modify its behavior in the +ApplicationController+.
 
   class ApplicationController < ActionController::Base
     rescue_from CanCan::AccessDenied do |exception|
@@ -71,132 +72,74 @@ If the user authorization fails, a CanCan::AccessDenied exception will be raised
     end
   end
 
+See {Exception Handling}[http://wiki.github.com/ryanb/cancan/exception-handling] for more information.
+
 
 == Defining Abilities
 
-As shown above, the Ability class is where all user permissions are defined. The user model is passed into the initialize method so you are free to modify the permissions based on the user's attributes. This way CanCan is completely decoupled with how you choose to handle roles.
+As shown above, the +Ability+ class is where all user permissions are defined. The user model is passed into the initialize method so the permissions can be modified based on any user attributes. CanCan makes no assumptions about how roles are handled in your application. See {Role Based Authorization}[http://wiki.github.com/ryanb/cancan/role-based-authorization] for an example.
 
-The "can" method accepts two arguments, the first one is the action you're setting the permission for, the second one is the class of object you're setting it on.
+The +can+ method is used to define permissions and requires two arguments. The first one is the action you're setting the permission for, the second one is the class of object you're setting it on.
 
   can :update, Article
 
-You can pass an array for either of these parameters to match any one.
+You can pass an array for either of these parameters to match any one. In this case the user will have the ability to update or destroy both articles and comments.
 
   can [:update, :destroy], [Article, Comment]
 
-In this case the user has the ability to update or destroy both articles and comments.
+Use :+manage+ to represent any action and :+all+ to represent any class. Here are some examples.
 
-You can pass a block to provide logic based on the article's attributes.
+  can :manage, Article   # has permissions to do anything to articles
+  can :read, :all        # has permission to read any model
+  can :manage, :all      # has permission to do anything to any model
 
-  can :update, Article do |article|
-    article && article.user == user
+You can pass a hash of conditions as the third argument to further restrict what the user is able to access. Here the user will only have permission to read active projects which he owns.
+
+  can :read, Project, :active => true, :user_id => user.id
+
+See {Defining Abilities with Hashes}[http://wiki.github.com/ryanb/cancan/defining-abilities-with-hashes] for more information.
+
+Blocks can also be used if you need more control.
+
+  can :update, Project do |project|
+    project && project.groups.include?(user.group)
   end
 
-If the block returns true then the user has that :update ability for that article, otherwise he will be denied access. It's possible for the passed in model to be nil if one isn't specified, so be sure to take that into consideration.
-
-You can pass :all to reference every type of object. In this case the object type will be passed into the block as well (just in case object is nil).
-
-  can :read, :all do |object_class, object|
-    object_class != Order
-  end
-
-Here the user has permission to read all objects except orders.
-
-You can also pass :manage as the action which will match any action. In this case the action is passed to the block.
-
-  can :manage, Comment do |action, comment|
-    action != :destroy
-  end
-  
-Finally, the "cannot" method works similar to "can" but defines which abilities cannot be done.
-
-  can :read, :all
-  cannot :read, Product
-
-
-== Checking Abilities
-
-Use the "can?" method in the controller or view to check the user's permission for a given action and object.
-
-  can? :destroy, @project
-
-You can also pass the class instead of an instance (if you don't have one handy).
-
-  <% if can? :create, Project %>
-    <%= link_to "New Project", new_project_path %>
-  <% end %>
-
-The "cannot?" method is for convenience and performs the opposite check of "can?"
-
-  cannot? :destroy, @project
+If the block returns true then the user has that :+update+ ability for that project, otherwise he will be denied access. See {Defining Abilities with Blocks}[http://wiki.github.com/ryanb/cancan/defining-abilities-with-blocks] for more information.
 
 
 == Aliasing Actions
 
-You can use the "alias_action" method to alias one or more actions into one.
-
-  alias_action :update, :destroy, :to => :modify
-  can :modify, Comment
-  can? :update, Comment # => true
-
-The following aliases are added by default for conveniently mapping common controller actions.
+You will usually be working with four actions when defining and checking permissions: :+read+, :+create+, :+update+, :+destroy+. These aren't the same as the 7 RESTful actions in Rails. CanCan adds some default aliases for mapping those actions.
 
   alias_action :index, :show, :to => :read
   alias_action :new, :to => :create
   alias_action :edit, :to => :update
 
+Notice the +edit+ action is aliased to +update+. If the user is able to update a record he also has permission to edit it. You can define your own aliases in the +Ability+ class
 
-== Authorizing Controller Actions
+  alias_action :update, :destroy, :to => :modify
+  can :modify, Comment
+  can? :update, Comment # => true
 
-As mentioned in the Getting Started section, you can use the +load_and_authorize_resource+ method in your controller to load the resource into an instance variable and authorize it. If you have a nested resource you can specify that as well.
-
-  load_and_authorize_resource :nested => :author
-
-You can also pass an array to the :+nested+ attribute for deep nesting.
-
-If you want to customize the loading behavior on certain actions, you can do so in a before filter.
-
-  class BooksController < ApplicationController
-    before_filter :find_book_by_permalink, :only => :show
-    load_and_authorize_resource
-  
-    private
-  
-    def find_book_by_permalink
-      @book = Book.find_by_permalink!(params[:id)
-    end
-  end
-
-Here the @book instance variable is already set so it will not be loaded again for that action. This works for nested resources as well.
+See {Custom Actions}[http://wiki.github.com/ryanb/cancan/custom-actions] for information on adding other actions.
 
 
-== Assumptions & Configuring
+== Fetching Records
 
-CanCan makes two assumptions about your application.
+In the controller +index+ action you may want to fetch only the records which the user has permission to read. You can do this with the +accessible_by+ scope.
 
-* You have an Ability class which defines the permissions.
-* You have a current_user method in the controller which returns the current user model.
+  @articles = Article.accessible_by(current_ability)
 
-You can override these by overriding the "current_ability" method in your ApplicationController.
-
-   def current_ability
-     UserAbility.new(current_account) # instead of Ability.new(current_user)
-   end
-
-That's it!
+See {Fetching Records}[http://wiki.github.com/ryanb/cancan/fetching-records] for more information.
 
 
-== Testing Abilities
-
-It is very easy to test the Ability model since you can call "can?" directly on it as you would in the view or controller.
-
-  def test "user can only destroy projects which he owns"
-    user = User.new
-    ability = Ability.new(user)
-    assert ability.can?(:destroy, Project.new(:user => user))
-    assert ability.cannot?(:destroy, Project.new)
-  end
+== Additional Docs
 
+* {Upgrading to 1.1}[http://wiki.github.com/ryanb/cancan/upgrading-to-11]
+* {Testing Abilities}[http://wiki.github.com/ryanb/cancan/testing-abilities]
+* {Accessing Request Data}[http://wiki.github.com/ryanb/cancan/accessing-request-data]
+* {See more}[http://wiki.github.com/ryanb/cancan/]
 
 == Special Thanks
 

cancan.gemspec

@@ -1,22 +1,15 @@
 Gem::Specification.new do |s|
   s.name        = "cancan"
+  s.version     = "1.1.0"
+  s.author      = "Ryan Bates"
+  s.email       = "ryan@railscasts.com"
+  s.homepage    = "http://github.com/ryanb/cancan"
   s.summary     = "Simple authorization solution for Rails."
   s.description = "Simple authorization solution for Rails which is completely decoupled from the user's roles. All permissions are stored in a single location for convenience."
-  s.homepage = "http://github.com/ryanb/cancan"
   
-  s.version = "1.0.2"
-  s.date = "2009-12-30"
+  s.files        = Dir["{lib,spec}/**/*", "[A-Z]*", "init.rb"]
+  s.require_path = "lib"
   
-  s.authors = ["Ryan Bates"]
-  s.email = "ryan@railscasts.com"
-  
-  s.require_paths = ["lib"]
-  s.files = Dir["lib/**/*"] + Dir["spec/**/*"] + ["LICENSE", "README.rdoc", "Rakefile", "CHANGELOG.rdoc", "init.rb"]
-  s.extra_rdoc_files = ["README.rdoc", "CHANGELOG.rdoc", "LICENSE"]
-  
-  s.has_rdoc = true
-  s.rdoc_options = ["--line-numbers", "--inline-source", "--title", "CanCan", "--main", "README.rdoc"]
-  
-  s.rubygems_version = "1.3.4"
-  s.required_rubygems_version = Gem::Requirement.new(">= 1.2")
+  s.rubyforge_project = s.name
+  s.required_rubygems_version = ">= 1.3.4"
 end

lib/cancan.rb

@@ -1,10 +1,6 @@
-module CanCan
-  # This error is raised when a user isn't allowed to access a given
-  # controller action. See ControllerAdditions#unauthorized! for details.
-  class AccessDenied < StandardError; end
-end
-
-require File.dirname(__FILE__) + '/cancan/ability'
-require File.dirname(__FILE__) + '/cancan/controller_resource'
-require File.dirname(__FILE__) + '/cancan/resource_authorization'
-require File.dirname(__FILE__) + '/cancan/controller_additions'
+require 'cancan/ability'
+require 'cancan/controller_resource'
+require 'cancan/resource_authorization'
+require 'cancan/controller_additions'
+require 'cancan/active_record_additions'
+require 'cancan/exceptions'

lib/cancan/ability.rb

@@ -16,8 +16,6 @@ module CanCan
   #   end
   # 
   module Ability
-    attr_accessor :user
-
     # Use to check the user's permission for a given action and object.
     # 
     #   can? :destroy, @project
@@ -26,6 +24,15 @@ module CanCan
     # 
     #   can? :create, Project
     # 
+    # Any additional arguments will be passed into the "can" block definition. This
+    # can be used to pass more information about the user's request for example.
+    # 
+    #   can? :create, Project, request.remote_ip
+    #   
+    #   can :create Project do |project, remote_ip|
+    #     # ...
+    #   end
+    # 
     # Not only can you use the can? method in the controller and view (see ControllerAdditions), 
     # but you can also call it directly on an ability instance.
     # 
@@ -40,15 +47,11 @@ module CanCan
     #     assert ability.cannot?(:destroy, Project.new)
     #   end
     # 
-    def can?(action, noun)
-      (@can_definitions || []).reverse.each do |base_behavior, defined_action, defined_noun, defined_block|
-        defined_actions = expand_actions(defined_action)
-        defined_nouns = [defined_noun].flatten
-        if includes_action?(defined_actions, action) && includes_noun?(defined_nouns, noun)
-          result = can_perform_action?(action, noun, defined_actions, defined_nouns, defined_block)
+    def can?(action, subject, *extra_args)
+      matching_can_definition(action, subject) do |base_behavior, defined_actions, defined_subjects, defined_conditions, defined_block|
+        result = can_perform_action?(action, subject, defined_actions, defined_subjects, defined_conditions, defined_block, extra_args)
         return base_behavior ? result : !result
       end
-      end
       false
     end
     
@@ -71,16 +74,26 @@ module CanCan
     #
     # In this case the user has the ability to update or destroy both articles and comments.
     # 
-    # You can pass a block to provide logic based on the article's attributes.
+    # You can pass a hash of conditions as the third argument.
     #
-    #   can :update, Article do |article|
-    #     article && article.user == user
+    #   can :read, Project, :active => true, :user_id => user.id
+    # 
+    # Here the user can only see active projects which he owns. See ControllerAdditions#conditions for a way to
+    # use this in database queries.
+    # 
+    # If the conditions hash does not give you enough control over defining abilities, you can use a block to
+    # write any Ruby code you want.
+    #
+    #   can :update, Project do |project|
+    #     project && project.groups.include?(user.group)
     #   end
     # 
-    # If the block returns true then the user has that :update ability for that article, otherwise he
+    # If the block returns true then the user has that :update ability for that project, otherwise he
     # will be denied access. It's possible for the passed in model to be nil if one isn't specified,
     # so be sure to take that into consideration.
     # 
+    # The downside to using a block is that it cannot be used to generate conditions for database queries.
+    # 
     # You can pass :all to reference every type of object. In this case the object type will be passed
     # into the block as well (just in case object is nil).
     # 
@@ -103,9 +116,9 @@ module CanCan
     #   can :read, :stats
     #   can? :read, :stats # => true
     # 
-    def can(action, noun, &block)
+    def can(action, subject, conditions = nil, &block)
       @can_definitions ||= []
-      @can_definitions << [true, action, noun, block]
+      @can_definitions << [true, action, subject, conditions, block]
     end
     
     # Define an ability which cannot be done. Accepts the same arguments as "can".
@@ -120,9 +133,9 @@ module CanCan
     #     product.invisible?
     #   end
     # 
-    def cannot(action, noun, &block)
+    def cannot(action, subject, conditions = nil, &block)
       @can_definitions ||= []
-      @can_definitions << [false, action, noun, block]
+      @can_definitions << [false, action, subject, conditions, block]
     end
     
     # Alias one or more actions into another one.
@@ -170,8 +183,37 @@ module CanCan
       @aliased_actions = {}
     end
     
+    # Returns a hash of conditions which match the given ability. This is useful if you need to generate a database
+    # query based on the current ability.
+    # 
+    #   can :read, Article, :visible => true
+    #   conditions :read, Article # returns { :visible => true }
+    # 
+    # Normally you will not call this method directly, but instead go through ActiveRecordAdditions#accessible_by method.
+    # 
+    # If the ability is not defined then false is returned so be sure to take that into consideration.
+    # If the ability is defined using a block then this will raise an exception since a hash of conditions cannot be
+    # determined from that.
+    def conditions(action, subject)
+      matching_can_definition(action, subject) do |base_behavior, defined_actions, defined_subjects, defined_conditions, defined_block|
+        raise Error, "Cannot determine ability conditions from block for #{action.inspect} #{subject.inspect}" if defined_block
+        return defined_conditions || {}
+      end
+      false
+    end
+    
     private
     
+    def matching_can_definition(action, subject, &block)
+      (@can_definitions || []).reverse.each do |base_behavior, defined_action, defined_subject, defined_conditions, defined_block|
+        defined_actions = expand_actions(defined_action)
+        defined_subjects = [defined_subject].flatten
+        if includes_action?(defined_actions, action) && includes_subject?(defined_subjects, subject)
+          return block.call(base_behavior, defined_actions, defined_subjects, defined_conditions, defined_block)
+        end
+      end
+    end
+    
     def default_alias_actions
       {
         :read => [:index, :show],
@@ -190,15 +232,35 @@ module CanCan
       end.flatten
     end
     
-    def can_perform_action?(action, noun, defined_actions, defined_nouns, defined_block)
-      if defined_block.nil?
-        true
-      else
+    def can_perform_action?(action, subject, defined_actions, defined_subjects, defined_conditions, defined_block, extra_args)
+      if defined_block
         block_args = []
         block_args << action if defined_actions.include?(:manage)
-        block_args << (noun.class == Class ? noun : noun.class) if defined_nouns.include?(:all)
-        block_args << (noun.class == Class ? nil : noun)
-        return defined_block.call(*block_args)
+        block_args << (subject.class == Class ? subject : subject.class) if defined_subjects.include?(:all)
+        block_args << (subject.class == Class ? nil : subject)
+        block_args += extra_args
+        defined_block.call(*block_args)
+      elsif defined_conditions
+        if subject.class == Class
+          true
+        else
+          matches_conditions? subject, defined_conditions
+        end
+      else
+        true
+      end
+    end
+    
+    def matches_conditions?(subject, defined_conditions)
+      defined_conditions.all? do |name, value|
+        attribute = subject.send(name)
+        if value.kind_of?(Hash)
+          matches_conditions? attribute, value
+        elsif value.kind_of?(Array) || value.kind_of?(Range)
+          value.include? attribute
+        else
+          attribute == value
+        end
       end
     end
     
@@ -206,8 +268,8 @@ module CanCan
       actions.include?(:manage) || actions.include?(action)
     end
     
-    def includes_noun?(nouns, noun)
-      nouns.include?(:all) || nouns.include?(noun) || nouns.any? { |c| c.kind_of?(Class) && noun.kind_of?(c) }
+    def includes_subject?(subjects, subject)
+      subjects.include?(:all) || subjects.include?(subject) || subjects.any? { |c| c.kind_of?(Class) && subject.kind_of?(c) }
     end
   end
 end

lib/cancan/active_record_additions.rb

@@ -0,0 +1,42 @@
+module CanCan
+  # This module is automatically included into all Active Record.
+  module ActiveRecordAdditions
+    module ClassMethods
+      # Returns a scope which fetches only the records that the passed ability
+      # can perform a given action on. The action defaults to :read. This
+      # is usually called from a controller and passed the +current_ability+.
+      #
+      #   @articles = Article.accessible_by(current_ability)
+      # 
+      # Here only the articles which the user is able to read will be returned.
+      # If the user does not have permission to read any articles then an empty
+      # result is returned. Since this is a scope it can be combined with any
+      # other scopes or pagination.
+      # 
+      # An alternative action can optionally be passed as a second argument.
+      # 
+      #   @articles = Article.accessible_by(current_ability, :update)
+      # 
+      # 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)
+        conditions = ability.conditions(action, self) || {:id => nil}
+        if respond_to? :where
+          where(conditions)
+        else
+          scoped(:conditions => conditions)
+        end
+      end
+    end
+    
+    def self.included(base)
+      base.extend ClassMethods
+    end
+  end
+end
+
+if defined? ActiveRecord
+  ActiveRecord::Base.class_eval do
+    include CanCan::ActiveRecordAdditions
+  end
+end

lib/cancan/controller_additions.rb

@@ -12,7 +12,7 @@ module CanCan
       #   end
       # 
       def load_and_authorize_resource(options = {})
-        before_filter(options.slice(:only, :except)) { |c| ResourceAuthorization.new(c, c.params, options.except(:only, :except)).load_and_authorize_resource }
+        ResourceAuthorization.add_before_filter(self, :load_and_authorize_resource, options)
       end
       
       # Sets up a before filter which loads the appropriate model resource into an instance variable.
@@ -59,8 +59,8 @@ module CanCan
       #   
       #     load_resource :nested => [:publisher, :author]
       #   
-      # [:+class+]
-      #   The class to use for the model.
+      # [:+resource+]
+      #   The class to use for the model (string or constant).
       #   
       # [:+collection+]
       #   Specify which actions are resource collection actions in addition to :+index+. This
@@ -77,7 +77,7 @@ module CanCan
       #     load_resource :new => :build
       # 
       def load_resource(options = {})
-        before_filter(options.slice(:only, :except)) { |c| ResourceAuthorization.new(c, c.params, options.except(:only, :except)).load_resource }
+        ResourceAuthorization.add_before_filter(self, :load_resource, options)
       end
       
       # Sets up a before filter which authorizes the current resource using the instance variable.
@@ -85,7 +85,7 @@ module CanCan
       # and ensure the user can perform the current action on it. Under the hood it is doing
       # something like the following.
       # 
-      #   unauthorized! if cannot?(params[:action].to_sym, @article || Article)
+      #   authorize!(params[:action].to_sym, @article || Article)
       # 
       # Call this method directly on the controller class.
       # 
@@ -102,11 +102,12 @@ module CanCan
       # [:+except+]
       #   Does not apply before filter to given actions.
       # 
-      # [:+class+]
-      #   The class to use for the model.
+      # [:+resource+]
+      #   The class to use for the model (string or constant). Alternatively pass a symbol
+      #   to represent a resource which does not have a class.
       # 
       def authorize_resource(options = {})
-        before_filter(options.slice(:only, :except)) { |c| ResourceAuthorization.new(c, c.params, options.except(:only, :except)).authorize_resource }
+        ResourceAuthorization.add_before_filter(self, :authorize_resource, options)
       end
     end
     
@@ -115,18 +116,21 @@ module CanCan
       base.helper_method :can?, :cannot?
     end
     
-    # Raises the CanCan::AccessDenied exception. This is often used in a
-    # controller action to mark a request as unauthorized.
+    # Raises a CanCan::AccessDenied exception if the current_ability cannot
+    # perform the given action. This is usually called in a controller action or
+    # before filter to perform the authorization.
     # 
     #   def show
     #     @article = Article.find(params[:id])
-    #     unauthorized! if cannot? :read, @article
+    #     authorize! :read, @article
     #   end
     # 
-    # The unauthorized! method accepts an optional argument which sets the
-    # message of the exception.
+    # A :message option can be passed to specify a different message.
     # 
-    # You can rescue from the exception in the controller to define the behavior.
+    #   authorize! :read, @article, :message => "Not authorized to read #{@article.name}"
+    # 
+    # You can rescue from the exception in the controller to customize how unauthorized
+    # access is displayed to the user.
     # 
     #   class ApplicationController < ActionController::Base
     #     rescue_from CanCan::AccessDenied do |exception|
@@ -135,22 +139,35 @@ module CanCan
     #     end
     #   end
     # 
-    # See the load_and_authorize_resource method to automatically add
-    # the "unauthorized!" behavior to a RESTful controller's actions.
-    def unauthorized!(message = "You are not authorized to access this page.")
-      raise AccessDenied, message
+    # See the CanCan::AccessDenied exception for more details on working with the exception.
+    # 
+    # See the load_and_authorize_resource method to automatically add the authorize! behavior
+    # to the default RESTful actions.
+    def authorize!(action, subject, *args)
+      message = nil
+      if args.last.kind_of?(Hash) && args.last.has_key?(:message)
+        message = args.pop[:message]
+      end
+      raise AccessDenied.new(message, action, subject) if cannot?(action, subject, *args)
     end
     
-    # Creates and returns the current user's ability. You generally do not invoke
-    # this method directly, instead you can override this method to change its
-    # behavior if the Ability class or current_user method are different.
+    def unauthorized!(message = nil)
+      raise ImplementationRemoved, "The unauthorized! method has been removed from CanCan, use authorize! instead."
+    end
+    
+    # Creates and returns the current user's ability and caches it. If you
+    # want to override how the Ability is defined then this is the place.
+    # Just define the method in the controller to change behavior.
     # 
     #   def current_ability
-    #     UserAbility.new(current_account) # instead of Ability.new(current_user)
+    #     # instead of Ability.new(current_user)
+    #     @current_ability ||= UserAbility.new(current_account)
     #   end
     # 
+    # Notice it is important to cache the ability object so it is not
+    # recreated every time.
     def current_ability
-      ::Ability.new(current_user)
+      @current_ability ||= ::Ability.new(current_user)
     end
     
     # Use in the controller or view to check the user's permission for a given action
@@ -166,7 +183,7 @@ module CanCan
     # 
     # This simply calls "can?" on the current_ability. See Ability#can?.
     def can?(*args)
-      (@current_ability ||= current_ability).can?(*args)
+      current_ability.can?(*args)
     end
     
     # Convenience method which works the same as "can?" but returns the opposite value.
@@ -174,7 +191,7 @@ module CanCan
     #   cannot? :destroy, @project
     # 
     def cannot?(*args)
-      (@current_ability ||= current_ability).cannot?(*args)
+      current_ability.cannot?(*args)
     end
   end
 end

lib/cancan/controller_resource.rb

@@ -1,6 +1,7 @@
 module CanCan
   class ControllerResource # :nodoc:
     def initialize(controller, name, parent = nil, options = {})
+      raise ImplementationRemoved, "The :class option has been renamed to :resource for specifying the class in CanCan." if options.has_key? :class
       @controller = controller
       @name = name
       @parent = parent
@@ -8,7 +9,13 @@ module CanCan
     end
     
     def model_class
-      @options[:class] || @name.to_s.camelize.constantize
+      if @options[:resource].nil?
+        @name.to_s.camelize.constantize
+      elsif @options[:resource].kind_of? String
+        @options[:resource].constantize
+      else
+        @options[:resource]
+      end
     end
     
     def find(id)

lib/cancan/exceptions.rb

@@ -0,0 +1,43 @@
+module CanCan
+  # A general CanCan exception
+  class Error < StandardError; end
+  
+  # Raised when removed code is called, an alternative solution is provided in message.
+  class ImplementationRemoved < Error; end
+  
+  # This error is raised when a user isn't allowed to access a given controller action.
+  # This usually happens within a call to ControllerAdditions#authorize! but can be
+  # raised manually.
+  # 
+  #   raise CanCan::AccessDenied.new("Not authorized!", :read, Article)
+  # 
+  # The passed message, action, and subject are optional and can later be retrieved when
+  # rescuing from the exception.
+  # 
+  #   exception.message # => "Not authorized!"
+  #   exception.action # => :read
+  #   exception.subject # => Article
+  # 
+  # If the message is not specified (or is nil) it will default to "You are anot authorized
+  # to access this page." This default can be overridden by setting default_message.
+  # 
+  #   exception.default_message = "Default error message"
+  #   exception.message # => "Default error message"
+  # 
+  # See ControllerAdditions#authorized! for more information on rescuing from this exception.
+  class AccessDenied < Error
+    attr_reader :action, :subject
+    attr_writer :default_message
+    
+    def initialize(message = nil, action = nil, subject = nil)
+      @message = message
+      @action = action
+      @subject = subject
+      @default_message = "You are not authorized to access this page."
+    end
+    
+    def to_s
+      @message || @default_message
+    end
+  end
+end

lib/cancan/matchers.rb

@@ -0,0 +1,13 @@
+Spec::Matchers.define :be_able_to do |*args|
+  match do |ability|
+    ability.can?(*args)
+  end
+
+  failure_message_for_should do |ability|
+    "expected to be able to #{args.map(&:inspect).join(" ")}"
+  end
+
+  failure_message_for_should_not do |ability|
+    "expected not to be able to #{args.map(&:inspect).join(" ")}"
+  end
+end

lib/cancan/resource_authorization.rb

@@ -2,6 +2,12 @@ module CanCan
   class ResourceAuthorization # :nodoc:
     attr_reader :params
     
+    def self.add_before_filter(controller_class, method, options = {})
+      controller_class.before_filter(options.slice(:only, :except)) do |controller|
+        new(controller, controller.params, options.except(:only, :except)).send(method)
+      end
+    end
+    
     def initialize(controller, params, options = {})
       @controller = controller
       @params = params
@@ -24,7 +30,7 @@ module CanCan
     end
     
     def authorize_resource
-      @controller.unauthorized! if @controller.cannot?(params[:action].to_sym, resource.model_instance || resource.model_class)
+      @controller.authorize!(params[:action].to_sym, resource.model_instance || resource.model_class)
     end
     
     private
@@ -48,7 +54,7 @@ module CanCan
     end
     
     def model_name
-      params[:controller].split('/').last.singularize
+      params[:controller].sub("Controller", "").underscore.split('/').last.singularize
     end
     
     def collection_actions

spec/cancan/ability_spec.rb

@@ -1,4 +1,4 @@
-require File.dirname(__FILE__) + '/../spec_helper'
+require "spec_helper"
 
 describe CanCan::Ability do
   before(:each) do
@@ -132,4 +132,60 @@ describe CanCan::Ability do
     @ability.clear_aliased_actions
     @ability.aliased_actions[:modify].should be_nil
   end
+  
+  it "should pass additional arguments to block from can?" do
+    @ability.can :read, Integer do |int, x|
+      int > x
+    end
+    @ability.can?(:read, 2, 1).should be_true
+    @ability.can?(:read, 2, 3).should be_false
+  end
+  
+  it "should use conditions as third parameter and determine abilities from it" do
+    @ability.can :read, Array, :first => 1, :last => 3
+    @ability.can?(:read, [1, 2, 3]).should be_true
+    @ability.can?(:read, [1, 2, 3, 4]).should be_false
+    @ability.can?(:read, Array).should be_true
+  end
+  
+  it "should allow an array of options in conditions hash" do
+    @ability.can :read, Array, :first => [1, 3, 5]
+    @ability.can?(:read, [1, 2, 3]).should be_true
+    @ability.can?(:read, [2, 3]).should be_false
+    @ability.can?(:read, [3, 4]).should be_true
+  end
+  
+  it "should allow a range of options in conditions hash" do
+    @ability.can :read, Array, :first => 1..3
+    @ability.can?(:read, [1, 2, 3]).should be_true
+    @ability.can?(:read, [3, 4]).should be_true
+    @ability.can?(:read, [4, 5]).should be_false
+  end
+  
+  it "should allow nested hashes in conditions hash" do
+    @ability.can :read, Array, :first => { :length => 5 }
+    @ability.can?(:read, ["foo", "bar"]).should be_false
+    @ability.can?(:read, ["test1", "foo"]).should be_true
+  end
+  
+  it "should return conditions for a given ability" do
+    @ability.can :read, Array, :first => 1, :last => 3
+    @ability.conditions(:show, Array).should == {:first => 1, :last => 3}
+  end
+  
+  it "should raise an exception when a block is used on condition" do
+    @ability.can :read, Array do |a|
+      true
+    end
+    lambda { @ability.conditions(:show, Array) }.should raise_error(CanCan::Error, "Cannot determine ability conditions from block for :show Array")
+  end
+  
+  it "should return an empty hash for conditions when there are no conditions" do
+    @ability.can :read, Array
+    @ability.conditions(:show, Array).should == {}
+  end
+  
+  it "should return false when performed on an action which isn't defined" do
+    @ability.conditions(:foo, Array).should == false
+  end
 end

spec/cancan/active_record_additions_spec.rb

@@ -0,0 +1,28 @@
+require "spec_helper"
+
+describe CanCan::ActiveRecordAdditions do
+  before(:each) do
+    @model_class = Class.new
+    stub(@model_class).scoped { :scoped_stub }
+    @model_class.send(:include, CanCan::ActiveRecordAdditions)
+    @ability = Object.new
+    @ability.extend(CanCan::Ability)
+  end
+  
+  it "should call where(:id => nil) when no ability is defined so no records are found" do
+    stub(@model_class).where(:id => nil) { :no_where }
+    @model_class.accessible_by(@ability, :read).should == :no_where
+  end
+  
+  it "should call where with matching ability conditions" do
+    @ability.can :read, @model_class, :foo => 1
+    stub(@model_class).where(:foo => 1) { :found_records }
+    @model_class.accessible_by(@ability, :read).should == :found_records
+  end
+  
+  it "should default to :read ability and use scoped when where isn't available" do
+    @ability.can :read, @model_class, :foo => 1
+    stub(@model_class).scoped(:conditions => {:foo => 1}) { :found_records }
+    @model_class.accessible_by(@ability).should == :found_records
+  end
+end

spec/cancan/controller_additions_spec.rb

@@ -1,33 +1,52 @@
-require File.dirname(__FILE__) + '/../spec_helper'
+require "spec_helper"
 
 describe CanCan::ControllerAdditions do
   before(:each) do
     @controller_class = Class.new
     @controller = @controller_class.new
     stub(@controller).params { {} }
+    stub(@controller).current_user { :current_user }
     mock(@controller_class).helper_method(:can?, :cannot?)
     @controller_class.send(:include, CanCan::ControllerAdditions)
   end
   
-  it "should raise access denied with default message when calling unauthorized!" do
-    lambda {
-      @controller.unauthorized!
-    }.should raise_error(CanCan::AccessDenied, "You are not authorized to access this page.")
+  it "should raise ImplementationRemoved when attempting to call 'unauthorized!' on a controller" do
+    lambda { @controller.unauthorized! }.should raise_error(CanCan::ImplementationRemoved)
   end
   
-  it "should raise access denied with custom message when calling unauthorized!" do
-    lambda {
-      @controller.unauthorized! "Access denied!"
-    }.should raise_error(CanCan::AccessDenied, "Access denied!")
+  it "should raise access denied exception if ability us unauthorized to perform a certain action" do
+    begin
+      @controller.authorize! :read, :foo, 1, 2, 3, :message => "Access denied!"
+    rescue CanCan::AccessDenied => e
+      e.message.should == "Access denied!"
+      e.action.should == :read
+      e.subject.should == :foo
+    else
+      fail "Expected CanCan::AccessDenied exception to be raised"
+    end
+  end
+  
+  it "should not raise access denied exception if ability is authorized to perform an action" do
+    @controller.current_ability.can :read, :foo
+    lambda { @controller.authorize!(:read, :foo) }.should_not raise_error
+  end
+  
+  it "should raise access denied exception with default message if not specified" do
+    begin
+      @controller.authorize! :read, :foo
+    rescue CanCan::AccessDenied => e
+      e.default_message = "Access denied!"
+      e.message.should == "Access denied!"
+    else
+      fail "Expected CanCan::AccessDenied exception to be raised"
+    end
   end
   
   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)
   end
   
   it "should provide a can? and cannot? methods which go through the current ability" do
-    stub(@controller).current_user { :current_user }
     @controller.current_ability.should be_kind_of(Ability)
     @controller.can?(:foo, :bar).should be_false
     @controller.cannot?(:foo, :bar).should be_true

spec/cancan/controller_resource_spec.rb

@@ -1,4 +1,4 @@
-require File.dirname(__FILE__) + '/../spec_helper'
+require "spec_helper"
 
 describe CanCan::ControllerResource do
   before(:each) do
@@ -43,7 +43,17 @@ describe CanCan::ControllerResource do
   
   it "should use the model class option if provided" do
     stub(Person).find(123) { :some_resource }
-    CanCan::ControllerResource.new(@controller, :ability, nil, :class => Person).find(123)
+    CanCan::ControllerResource.new(@controller, :ability, nil, :resource => Person).find(123)
     @controller.instance_variable_get(:@ability).should == :some_resource
   end
+  
+  it "should convert string to constant for resource" do
+    CanCan::ControllerResource.new(@controller, :ability, nil, :resource => "Person").model_class.should == Person
+  end
+  
+  it "should raise an exception when specifying :class option since it is no longer used" do
+    lambda {
+      CanCan::ControllerResource.new(@controller, :ability, nil, :class => Person)
+    }.should raise_error(CanCan::ImplementationRemoved)
+  end
 end

spec/cancan/exceptions_spec.rb

@@ -0,0 +1,35 @@
+require "spec_helper"
+
+describe CanCan::AccessDenied do
+  describe "with action and subject" do
+    before(:each) do
+      @exception = CanCan::AccessDenied.new(nil, :some_action, :some_subject)
+    end
+    
+    it "should have action and subject accessors" do
+      @exception.action.should == :some_action
+      @exception.subject.should == :some_subject
+    end
+    
+    it "should have a changable default message" do
+      @exception.message.should == "You are not authorized to access this page."
+      @exception.default_message = "Unauthorized!"
+      @exception.message.should == "Unauthorized!"
+    end
+  end
+  
+  describe "with only a message" do
+    before(:each) do
+      @exception = CanCan::AccessDenied.new("Access denied!")
+    end
+    
+    it "should have nil action and subject" do
+      @exception.action.should be_nil
+      @exception.subject.should be_nil
+    end
+    
+    it "should have passed message" do
+      @exception.message.should == "Access denied!"
+    end
+  end
+end

spec/cancan/matchers_spec.rb

@@ -0,0 +1,33 @@
+require "spec_helper"
+
+describe "be_able_to" do
+  it "delegates to can?" do
+    object = Object.new
+    mock(object).can?(:read, 123) { true }
+    object.should be_able_to(:read, 123)
+  end
+
+  it "reports a nice failure message for should" do
+    object = Object.new
+    mock(object).can?(:read, 123) { false }
+    expect do
+      object.should be_able_to(:read, 123)
+    end.should raise_error('expected to be able to :read 123')
+  end
+
+  it "reports a nice failure message for should not" do
+    object = Object.new
+    mock(object).can?(:read, 123) { true }
+    expect do
+      object.should_not be_able_to(:read, 123)
+    end.should raise_error('expected not to be able to :read 123')
+  end
+
+  it "delegates additional arguments to can? and reports in failure message" do
+    object = Object.new
+    mock(object).can?(:read, 123, 456) { false }
+    expect do
+      object.should be_able_to(:read, 123, 456)
+    end.should raise_error('expected to be able to :read 123 456')
+  end
+end

spec/cancan/resource_authorization_spec.rb

@@ -1,9 +1,8 @@
-require File.dirname(__FILE__) + '/../spec_helper'
+require "spec_helper"
 
 describe CanCan::ResourceAuthorization do
   before(:each) do
     @controller = Object.new # simple stub for now
-    stub(@controller).unauthorized! { raise CanCan::AccessDenied }
   end
   
   it "should load the resource into an instance variable if params[:id] is specified" do
@@ -20,6 +19,13 @@ describe CanCan::ResourceAuthorization do
     @controller.instance_variable_get(:@ability).should == :some_resource
   end
   
+  it "should properly load resource for namespaced controller when using '::' for namespace" do
+    stub(Ability).find(123) { :some_resource }
+    authorization = CanCan::ResourceAuthorization.new(@controller, :controller => "Admin::AbilitiesController", :action => "show", :id => 123)
+    authorization.load_resource
+    @controller.instance_variable_get(:@ability).should == :some_resource
+  end
+  
   it "should build a new resource with hash if params[:id] is not specified" do
     stub(Ability).new(:foo => "bar") { :some_resource }
     authorization = CanCan::ResourceAuthorization.new(@controller, :controller => "abilities", :action => "create", :ability => {:foo => "bar"})
@@ -42,19 +48,15 @@ describe CanCan::ResourceAuthorization do
   
   it "should perform authorization using controller action and loaded model" do
     @controller.instance_variable_set(:@ability, :some_resource)
-    stub(@controller).cannot?(:show, :some_resource) { true }
+    stub(@controller).authorize!(:show, :some_resource) { raise CanCan::AccessDenied }
     authorization = CanCan::ResourceAuthorization.new(@controller, :controller => "abilities", :action => "show")
-    lambda {
-      authorization.authorize_resource
-    }.should raise_error(CanCan::AccessDenied)
+    lambda { authorization.authorize_resource }.should raise_error(CanCan::AccessDenied)
   end
   
   it "should perform authorization using controller action and non loaded model" do
-    stub(@controller).cannot?(:show, Ability) { true }
+    stub(@controller).authorize!(:show, Ability) { raise CanCan::AccessDenied }
     authorization = CanCan::ResourceAuthorization.new(@controller, :controller => "abilities", :action => "show")
-    lambda {
-      authorization.authorize_resource
-    }.should raise_error(CanCan::AccessDenied)
+    lambda { authorization.authorize_resource }.should raise_error(CanCan::AccessDenied)
   end
   
   it "should call load_resource and authorize_resource for load_and_authorize_resource" do
@@ -108,7 +110,7 @@ describe CanCan::ResourceAuthorization do
   
   it "should load the model using a custom class" do
     stub(Person).find(123) { :some_resource }
-    authorization = CanCan::ResourceAuthorization.new(@controller, {:controller => "abilities", :action => "show", :id => 123}, {:class => Person})
+    authorization = CanCan::ResourceAuthorization.new(@controller, {:controller => "abilities", :action => "show", :id => 123}, {:resource => Person})
     authorization.load_resource
     @controller.instance_variable_get(:@ability).should == :some_resource
   end

spec/spec_helper.rb

@@ -4,7 +4,8 @@ require 'active_support'
 require 'active_record'
 require 'action_controller'
 require 'action_view'
-require File.dirname(__FILE__) + '/../lib/cancan.rb'
+require 'cancan'
+require 'cancan/matchers'
 
 Spec::Runner.configure do |config|
   config.mock_with :rr