moving accessible_by out into ModelAdditions module

lib/cancan.rb

@@ -2,6 +2,7 @@ require 'cancan/ability'
 require 'cancan/rule'
 require 'cancan/controller_resource'
 require 'cancan/controller_additions'
+require 'cancan/model_additions'
 require 'cancan/exceptions'
 require 'cancan/query'
 require 'cancan/inherited_resource'

lib/cancan/exceptions.rb

@@ -2,6 +2,9 @@ module CanCan
   # A general CanCan exception
   class Error < StandardError; end
 
+  # Raised when behavior is not implemented, usually used in an abstract class.
+  class NotImplemented < Error; end
+
   # Raised when removed code is called, an alternative solution is provided in message.
   class ImplementationRemoved < Error; end
 

lib/cancan/model_adapters/abstract_adapter.rb

@@ -19,6 +19,11 @@ module CanCan
         @model_class = model_class
         @rules = rules
       end
+
+      def database_records
+        # This should be overridden in a subclass to return records which match @rules
+        raise NotImplemented, "This model adapter does not support fetching records from the database."
+      end
     end
   end
 end

lib/cancan/model_adapters/active_record_adapter.rb

@@ -6,7 +6,7 @@ module CanCan
       end
 
       # Returns conditions intended to be used inside a database query. Normally you will not call this
-      # method directly, but instead go through ActiveRecordAdditions#accessible_by.
+      # method directly, but instead go through ModelAdditions#accessible_by.
       #
       # If there is only one "can" definition, a hash of conditions will be returned matching the one defined.
       #
@@ -44,7 +44,7 @@ module CanCan
       end
 
       # Returns the associations used in conditions for the :joins option of a search.
-      # See ActiveRecordAdditions#accessible_by for use in Active Record.
+      # See ModelAdditions#accessible_by
       def joins
         joins_hash = {}
         @rules.each do |rule|
@@ -114,40 +114,6 @@ module CanCan
   end
 end
 
-module CanCan
+ActiveRecord::Base.class_eval do
-  # This module is automatically included into all Active Record models.
+  include CanCan::ModelAdditions
-  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)
-        ability.model_adapter(self, action).database_records
-      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/model_adapters/data_mapper_adapter.rb

@@ -20,35 +20,6 @@ module CanCan
   end
 end
 
-module CanCan
+DataMapper::Model.class_eval do
-  module DataMapperAdditions
+  include CanCan::ModelAdditions::ClassMethods
-    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)
-        ability.model_adapter(self, action).database_records
-      end
-    end
-  end
-end
-
-if Object.const_defined?('DataMapper')
-  DataMapper::Model.class_eval do
-    include CanCan::DataMapperAdditions::ClassMethods
-  end
 end

lib/cancan/model_adapters/mongoid_adapter.rb

@@ -2,7 +2,7 @@ module CanCan
   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
+        model_class <= Mongoid::Document
       end
 
       def database_records
@@ -50,35 +50,6 @@ module CanCan
     alias_method :matches_conditions_hash_without_mongoid_subject?, :matches_conditions_hash?
     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
-      # 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)
-        ability.model_adapter(self, action).database_records
-      end
-    end
-
-    def self.included(base)
-      base.extend ClassMethods
-    end
-  end
 end
 
 # Info on monkeypatching Mongoid :
@@ -90,7 +61,7 @@ if defined?(::Mongoid)
       old_block = @_included_block
       @_included_block = Proc.new do
         class_eval(&old_block) if old_block
-        include CanCan::MongoidAdditions
+        include CanCan::ModelAdditions
       end
     end
   end

lib/cancan/model_additions.rb

@@ -0,0 +1,31 @@
+module CanCan
+
+  # This module adds the accessible_by class method to a model. It is included in the model adapters.
+  module ModelAdditions
+    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.
+      def accessible_by(ability, action = :read)
+        ability.model_adapter(self, action).database_records
+      end
+    end
+
+    def self.included(base)
+      base.extend ClassMethods
+    end
+  end
+end

lib/cancan/query.rb

@@ -1,7 +1,7 @@
 module CanCan
 
   # Generates the sql conditions and association joins for use in ActiveRecord queries.
-  # Normally you will not use this class directly, but instead through ActiveRecordAdditions#accessible_by.
+  # Normally you will not use this class directly, but instead through ModelAdditions#accessible_by.
   class Query
     def initialize(sanitizer, rules)
       @sanitizer = sanitizer
@@ -9,7 +9,7 @@ module CanCan
     end
 
     # Returns conditions intended to be used inside a database query. Normally you will not call this
-    # method directly, but instead go through ActiveRecordAdditions#accessible_by.
+    # method directly, but instead go through ModelAdditions#accessible_by.
     #
     # If there is only one "can" definition, a hash of conditions will be returned matching the one defined.
     #

spec/cancan/model_adapters/mongoid_adapter_spec.rb

@@ -3,14 +3,14 @@ if ENV["MODEL_ADAPTER"] == "mongoid"
 
   class MongoidCategory
     include Mongoid::Document
-    include CanCan::MongoidAdditions
+    include CanCan::ModelAdditions
 
     references_many :mongoid_projects
   end
 
   class MongoidProject
     include Mongoid::Document
-    include CanCan::MongoidAdditions
+    include CanCan::ModelAdditions
 
     referenced_in :mongoid_category