redmine_observers.rb

### init.rb

require 'dispatcher'

Dispatcher.to_prepare do
  require 'my_moo_patch'
  Journal.send(:include, ObserverJournalPatch)
end

### lib/observer_journal_patch.rb

require_dependency 'journal'

module ObserverJournalPatch
  def self.included(base) # :nodoc:
    base.extend(ClassMethods)

    base.send(:include, InstanceMethods)

    base.class_eval do
      unloadable # Send unloadable so it will not be unloaded in development
      before_save :check_thing
    end

  end
  
  module ClassMethods
  end
  
  module InstanceMethods
    def check_thing
      return false
    end
  end
end