Introduce after_{create,update,delete}_commit callbacks

Those are actually shortcuts for `after_commit`.

Before:

    after_commit :add_to_index_later, on: :create
    after_commit :update_in_index_later, on: :update
    after_commit :remove_from_index_later, on: :destroy

After:

    after_create_commit  :add_to_index_later
    after_update_commit  :update_in_index_later
    after_destroy_commit :remove_from_index_later

1 files changed, 23 insertions, 3 deletions

diff --git a/activerecord/lib/active_record/transactions.rb b/activerecord/lib/active_record/transactions.rb
index 8de82feae3..38ab1f3fc6 100644
--- a/activerecord/lib/active_record/transactions.rb
+++ b/activerecord/lib/active_record/transactions.rb
@@ -233,6 +233,24 @@ module ActiveRecord
         set_callback(:commit, :after, *args, &block)
       end
 
+      # Shortcut for +after_commit :hook, on: :create+.
+      def after_create_commit(*args, &block)
+        set_options_for_callbacks!(args, on: :create)
+        set_callback(:commit, :after, *args, &block)
+      end
+
+      # Shortcut for +after_commit :hook, on: :update+.
+      def after_update_commit(*args, &block)
+        set_options_for_callbacks!(args, on: :update)
+        set_callback(:commit, :after, *args, &block)
+      end
+
+      # Shortcut for +after_commit :hook, on: :destroy+.
+      def after_destroy_commit(*args, &block)
+        set_options_for_callbacks!(args, on: :destroy)
+        set_callback(:commit, :after, *args, &block)
+      end
+
       # This callback is called after a create, update, or destroy are rolled back.
       #
       # Please check the documentation of #after_commit for options.
@@ -268,9 +286,11 @@ module ActiveRecord
 
       private
 
-      def set_options_for_callbacks!(args)
-        options = args.last
-        if options.is_a?(Hash) && options[:on]
+      def set_options_for_callbacks!(args, enforced_options = {})
+        options = args.extract_options!.merge!(enforced_options)
+        args << options
+
+        if options[:on]
           fire_on = Array(options[:on])
           assert_valid_transaction_action(fire_on)
           options[:if] = Array(options[:if])