Add support for Redmine 4 / Rails 5 // fixes #14

init.rb

@@ -32,10 +32,17 @@
 end
 
 
+# Patches to the Redmine core.
+require 'dispatcher' unless Rails::VERSION::MAJOR >= 3
 # Patches to the Redmine core.
 require 'dispatcher' unless Rails::VERSION::MAJOR >= 3
 
-if Rails::VERSION::MAJOR >= 3
+if Rails::VERSION::MAJOR >= 5
+  ActiveSupport::Reloader.to_prepare do
+    require_dependency 'application_controller'
+    AttachmentsController.send(:include, MaintenanceMode)
+  end
+elsif Rails::VERSION::MAJOR >= 3
   ActionDispatch::Callbacks.to_prepare do
     require_dependency 'application_controller'
     ApplicationController.send(:include, MaintenanceMode)

lib/maintenance_mode.rb

@@ -22,7 +22,7 @@ def show_maintenance_mode_page
         end
       end
 
-      before_filter(:show_maintenance_mode_page)
+      before_action(:show_maintenance_mode_page)
 
     end
   end