Move creation of scopes to persistence adapaters

- extend the classes with create_scope method
- avoid expensive "klass.ancestors.map" checks
- ORM-specific code is in one place

lib/aasm/persistence/active_record_persistence.rb

@@ -31,6 +31,7 @@ module ActiveRecordPersistence
       def self.included(base)
         base.send(:include, AASM::Persistence::Base)
         base.send(:include, AASM::Persistence::ActiveRecordPersistence::InstanceMethods)
+        base.extend AASM::Persistence::ActiveRecordPersistence::ClassMethods
 
         base.after_initialize do
           aasm_ensure_initial_state
@@ -40,6 +41,23 @@ def self.included(base)
         base.validate :aasm_validate_states
       end
 
+      module ClassMethods
+        def aasm_create_scope(state_machine_name, scope_name)
+          conditions = {
+            table_name => { aasm(state_machine_name).attribute_name => scope_name.to_s }
+          }
+          if ActiveRecord::VERSION::MAJOR >= 3
+            class_eval do
+              scope scope_name, lambda { where(conditions) }
+            end
+          else
+            class_eval do
+              named_scope scope_name, :conditions => conditions
+            end
+          end
+        end
+      end
+
       module InstanceMethods
 
         # Writes <tt>state</tt> to the state column and persists it to the database

lib/aasm/persistence/base.rb

@@ -63,53 +63,11 @@ def state_with_scope(name, *args)
     private
 
     def create_scope?(name)
-      @state_machine.config.create_scopes && !@klass.respond_to?(name)
+      @state_machine.config.create_scopes && !@klass.respond_to?(name) && @klass.respond_to?(:aasm_create_scope)
     end
 
     def create_scope(name)
-      if ancestors_include?("ActiveRecord::Base")
-        create_for_active_record(name)
-      elsif ancestors_include?("Mongoid::Document")
-        create_for_mongoid(name)
-      elsif ancestors_include?("MongoMapper::Document")
-        create_for_mongomapper(name)
-      end
-    end
-
-    def ancestors_include?(class_name)
-      @klass.ancestors.map { |klass| klass.to_s }.include?(class_name)
-    end
-
-    def create_for_active_record(name)
-      conditions = {
-        @klass.table_name => { @klass.aasm(@name).attribute_name => name.to_s }
-      }
-      if ActiveRecord::VERSION::MAJOR >= 3
-        @klass.class_eval do
-          scope name, lambda { where(conditions) }
-        end
-      else
-        @klass.class_eval do
-          named_scope name, :conditions => conditions
-        end
-      end
-    end
-
-    def create_for_mongoid(name)
-      klass = @klass
-      state_machine_name = @name
-      scope_options = lambda {
-        klass.send(
-          :where,
-          { klass.aasm(state_machine_name).attribute_name.to_sym => name.to_s }
-        )
-      }
-      @klass.send(:scope, name, scope_options)
-    end
-
-    def create_for_mongomapper(name)
-      conditions = { @klass.aasm(@name).attribute_name.to_sym => name.to_s }
-      @klass.scope(name, lambda { @klass.where(conditions) })
+      @klass.aasm_create_scope(@name, name)
     end
   end # Base
 

lib/aasm/persistence/mongo_mapper_persistence.rb

@@ -33,13 +33,21 @@ module MongoMapperPersistence
       def self.included(base)
         base.send(:include, AASM::Persistence::Base)
         base.send(:include, AASM::Persistence::MongoMapperPersistence::InstanceMethods)
+        base.extend AASM::Persistence::MongoMapperPersistence::ClassMethods
 
         base.before_create :aasm_ensure_initial_state
 
         # ensure state is in the list of states
         base.validate :aasm_validate_states
       end
 
+      module ClassMethods
+        def aasm_create_scope(state_machine_name, scope_name)
+          conditions = { aasm(state_machine_name).attribute_name.to_sym => scope_name.to_s }
+          scope(scope_name, lambda { where(conditions) })
+        end
+      end
+
       module InstanceMethods
 
         # Writes <tt>state</tt> to the state column and persists it to the database

lib/aasm/persistence/mongoid_persistence.rb

@@ -33,10 +33,23 @@ module MongoidPersistence
       def self.included(base)
         base.send(:include, AASM::Persistence::Base)
         base.send(:include, AASM::Persistence::MongoidPersistence::InstanceMethods)
+        base.extend AASM::Persistence::MongoidPersistence::ClassMethods
 
         base.after_initialize :aasm_ensure_initial_state
       end
 
+      module ClassMethods
+        def aasm_create_scope(state_machine_name, scope_name)
+          scope_options = lambda {
+            send(
+              :where,
+              { aasm(state_machine_name).attribute_name.to_sym => scope_name.to_s }
+            )
+          }
+          send(:scope, scope_name, scope_options)
+        end
+      end
+
       module InstanceMethods
 
         # Writes <tt>state</tt> to the state column and persists it to the database