keeping track of who did what

hello everybody. i need to log "who did what" on some models. i was reading recipe 59 of rails recipes and i created something like that:

class LogSweeper < ActionController::Caching::Sweeper   observe :model1, :model2, :model3, :model4, :model5, ...

  after_save(model)     save_log(model, "save")   end

  after_destroy(model)      save_log(model, "destroy)   end

  private   save_log(model, event, user_id = controller.session[:account_id])     #create the log entry, i want to save the id of the model, the id of the logged user and something to describe the action.     #controller isn't defined here so i can't access the user_id.   end end

in environment.rb i added:   config.active_record.observers = :log_sweeper

the sweeper is called when something happen to the observed models, but i can't access the controller (and so, the user_id) from there. any help?

Why not use one of the versioning/auditing gems (http://ruby- instead?