Comments on: Making Session Data Available to Models in Ruby on Rails

By: Daniel

Daniel — Wed, 01 Oct 2008 13:26:46 +0000

Instead of cache_sweeper i use a similar implementation. Just include Auditing to your controller and your observer should inherit the Auditing::Observer. This is a lot cleaner approach than using TLS which might be server/implementation specific.

 module Auditing
  def self.included(base)
    ActiveRecord::Base.observers.each do |observer|
      observer = if observer.respond_to?(:to_sym)
        observer.to_s.camelize.constantize.instance
      elsif observer.respond_to?(:instance)
        observer.instance
      else
        raise ArgumentError, "#{observer} is an invalid class name"
      end
      base.around_filter(observer) if observer.is_a?(Auditing::Observer)
    end
  end
 
  class Observer &lt; ActiveRecord::Observer
    attr_accessor :controller
 
    def before(controller)
      self.controller = controller
    end
 
    def after(controller)
      self.controller = nil
    end
  end
 
end

By: Sam

Sam — Thu, 29 Nov 2007 19:04:21 +0000

Is there a simple way to explicitly specify that your app requires mongrel version <= (whatever version is current at the time of writing)? Cause then this is actually not so bad.

By: Prateek

Prateek — Thu, 25 Oct 2007 07:38:02 +0000

I am reading rails recipes and they mention “Cache Sweepers” as a possible solution for this problem. I am yet to try it out, but you can look at that as an alternative too

Regards
Prateek

By: SynTruth

SynTruth — Wed, 05 Sep 2007 14:07:15 +0000

I got around this in another way. I created a lib in the {RAILS_ROOT}/lib directory that was loaded in config/enviroment.rb. It contains helper functions like is_logged_in?() and get_user_id() that checked for @session and @session[:user] and such, and returned things as needed, these are callable from within the model structure since they are global.

By: Niko

Niko — Thu, 16 Aug 2007 12:00:05 +0000

I’ve no idea wether this concern is valid, but will it work with the Evented Mongrel Swiftiply is using? Is it using one thread per request, too?

By: Kai Krakow

Kai Krakow — Thu, 16 Aug 2007 10:14:56 +0000

Very nice article. It helped me tracking the session user in an audit log which would otherwise have been pretty useless. But how safe is this to use on Apache2 mpm-worker with mod-fcgid? As far as I can see, the before_filter stores the session user in a local thread var on each request in the beginning, so the data stored there should be correct throughout the whole request. Does this hold true on Apache2 mpm-worker with mod-fcgid?

By: Geoff Lane

Geoff Lane — Sat, 11 Aug 2007 03:45:55 +0000

Alex,
That’s a very good point. Luckily if you are using Mongrel to deploy your Rails app it creates a new thread to handle each request. If anyone is concerned, then just stick with the ActionController::Caching::Sweeper method mentioned in the article.

By: Alex

Alex — Thu, 09 Aug 2007 07:03:26 +0000

I’ve done similar things in other architectures. This is useful, but if the container reuses threads (as can happen in J2EE) you can have serious security and other issues.