Implementation of making embedded callbacks optional.

Something to get the discussion started...

lib/mongo_mapper/plugins/embedded_callbacks.rb

@@ -9,22 +9,46 @@ module EmbeddedCallbacks
 
         define_model_callbacks :save, :create, :update, :destroy, :only => [:before, :after]
         define_model_callbacks :touch, :only => [:after]
+
+        embedded_callbacks_on
       end
 
-      def run_callbacks(callback, *args, &block)
-        embedded_docs = []
+      module ClassMethods
+        def embedded_callbacks_on
+          @embedded_callbacks_status = true
+        end
+
+        def embedded_callbacks_off
+          @embedded_callbacks_status = false
+        end
+
+        def embedded_callbacks_on?
+          @embedded_callbacks_status == true
+        end
 
-        embedded_associations.each do |association|
-          embedded_docs += Array(get_proxy(association).send(:load_target))
+        def embedded_callbacks_off?
+          !embedded_callbacks_on?
         end
+      end
+
+      def run_callbacks(callback, *args, &block)
+
+        if self.class.embedded_callbacks_on?
+          embedded_docs = []
 
-        block = embedded_docs.inject(block) do |chain, doc|
-          if doc.class.respond_to?("_#{callback}_callbacks")
-            lambda { doc.run_callbacks(callback, *args, &chain) }
-          else
-            chain
+          embedded_associations.each do |association|
+            embedded_docs += Array(get_proxy(association).send(:load_target))
+          end
+
+          block = embedded_docs.inject(block) do |chain, doc|
+            if doc.class.respond_to?("_#{callback}_callbacks")
+              lambda { doc.run_callbacks(callback, *args, &chain) }
+            else
+              chain
+            end
           end
         end
+
         super callback, *args, &block
       end
     end

test/functional/test_callbacks.rb

@@ -106,7 +106,7 @@ class CallbacksTest < Test::Unit::TestCase
       @child_class       = EDoc { include CallbacksSupport }
       @grand_child_class = EDoc { include CallbacksSupport }
 
-      @root_class.many :children, :class => @child_class
+      @root_class.many  :children, :class => @child_class
       @child_class.many :children, :class => @grand_child_class
     end
 
@@ -156,13 +156,60 @@ class CallbacksTest < Test::Unit::TestCase
     end
   end
 
+  context "Turning embedded callbacks off" do
+    setup do
+      @root_class        = Doc  { include CallbacksSupport; embedded_callbacks_off }
+      @child_class       = EDoc { include CallbacksSupport; embedded_callbacks_off }
+      @grand_child_class = EDoc { include CallbacksSupport; embedded_callbacks_off }
+
+      @root_class.many  :children, :class => @child_class
+      @child_class.many :children, :class => @grand_child_class
+
+      @root_class.many  :children, :class => @child_class
+      @child_class.many :children, :class => @grand_child_class
+    end
+
+    should "not run create callbacks" do
+      grand = @grand_child_class.new(:name => 'Grand Child')
+      child = @child_class.new(:name => 'Child', :children => [grand])
+      root  = @root_class.create(:name => 'Parent', :children => [child])
+
+      root.children.first.history.should == []
+      root.children.first.children.first.history.should == []
+    end
+
+    should "not run update callbacks" do
+      grand = @grand_child_class.new(:name => 'Grand Child')
+      child = @child_class.new(:name => 'Child', :children => [grand])
+      root  = @root_class.create(:name => 'Parent', :children => [child])
+      root.clear_history
+      root.update_attributes(:name => 'Updated Parent')
+
+      root.children.first.history.should == []
+      root.children.first.children.first.history.should == []
+    end
+
+    should "not run destroy callbacks" do
+      grand = @grand_child_class.new(:name => 'Grand Child')
+      child = @child_class.new(:name => 'Child', :children => [grand])
+      root  = @root_class.create(:name => 'Parent', :children => [child])
+      root.destroy
+      child = root.children.first
+      child.history.should == []
+
+      grand = root.children.first.children.first
+      grand.history.should == []
+    end
+  end
+
   context "Running validation callbacks with conditional execution" do
     setup do
       @document = Doc do
         include CallbacksSupport
         key :message, String
 
         before_validation :set_message, :on => 'create'
+
         def set_message
           self['message'] = 'Hi!'
         end
@@ -182,4 +229,4 @@ def set_message
       doc.message.should == 'Ho!'
     end
   end
-end
+end