1 files changed, 37 insertions, 0 deletions
diff --git a/actionpack/lib/action_dispatch/middleware/callbacks.rb b/actionpack/lib/action_dispatch/middleware/callbacks.rb
new file mode 100644
index 0000000000..baf9d5779e
--- /dev/null
+++ b/actionpack/lib/action_dispatch/middleware/callbacks.rb
@@ -0,0 +1,37 @@
+
+module ActionDispatch
+  # Provide callbacks to be executed before and after the request dispatch.
+  class Callbacks
+    include ActiveSupport::Callbacks
+
+    define_callbacks :call
+
+    class << self
+      delegate :to_prepare, :to_cleanup, :to => "ActionDispatch::Reloader"
+
+      def before(*args, &block)
+        set_callback(:call, :before, *args, &block)
+      end
+
+      def after(*args, &block)
+        set_callback(:call, :after, *args, &block)
+      end
+    end
+
+    def initialize(app)
+      @app = app
+    end
+
+    def call(env)
+      error = nil
+      result = run_callbacks :call do
+        begin
+          @app.call(env)
+        rescue => error
+        end
+      end
+      raise error if error
+      result
+    end
+  end
+end