1 files changed, 57 insertions, 0 deletions
diff --git a/railties/lib/rails/application/routes_reloader.rb b/railties/lib/rails/application/routes_reloader.rb
new file mode 100644
index 0000000000..6da903c1ac
--- /dev/null
+++ b/railties/lib/rails/application/routes_reloader.rb
@@ -0,0 +1,57 @@
+module Rails
+  class Application
+    class RoutesReloader < ::ActiveSupport::FileUpdateChecker
+      def initialize
+        super([]) { reload! }
+      end
+
+      def blocks
+        @blocks ||= {}
+      end
+
+      def reload!
+        clear!
+        load_blocks
+        load_paths
+        finalize!
+      ensure
+        revert
+      end
+
+    protected
+
+      def clear!
+        routers.each do |routes|
+          routes.disable_clear_and_finalize = true
+          routes.clear!
+        end
+      end
+
+      def load_blocks
+        blocks.each do |routes, block|
+          routes.draw(&block) if block
+        end
+      end
+
+      def load_paths
+        paths.each { |path| load(path) }
+      end
+
+      def finalize!
+        routers.each do |routes|
+          ActiveSupport.on_load(:action_controller) { routes.finalize! }
+        end
+      end
+
+      def revert
+        routers.each do |routes|
+          routes.disable_clear_and_finalize = false
+        end
+      end
+
+      def routers
+        blocks.keys
+      end
+    end
+  end
+end