# Know what was updated **URL:** \ **Category:** Rails\ **Created:** [May 28, 2009, 12:42pm UTC](https://www.ruby-forum.com/t/know-what-was-updated/169013 "2009-05-28T12:42:42Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![blueomega](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/e95f7d/32.png) [@blueomega](https://www.ruby-forum.com/u/blueomega)\ **Post date:** [May 28, 2009, 12:42pm UTC](https://www.ruby-forum.com/t/know-what-was-updated/169013/1 "2009-05-28T12:42:42Z")
I am doing a rss feed who reports all the changes in the program. all changes are sent to a database where the afected item, who made changed, time of change and a string reporting the change is kept the problem is that the string who reports the change is too generic, something like: Task ‘xtask’ was updated i would like to know if its possible to know what was changed with update\_attributes (i know it updates all the attributes), without needing to check the before and after in the database the hash parameters for update\_attributes come from a form\_for ---
**Author:** ![blueomega](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/e95f7d/32.png) [@blueomega](https://www.ruby-forum.com/u/blueomega)\ **Post date:** [May 28, 2009, 5:15pm UTC](https://www.ruby-forum.com/t/know-what-was-updated/169013/2 "2009-05-28T17:15:06Z")
First, get familiar with model callbacks if you’re not already because you don’t want to put this logic in the controller: > **[rails.info](http://guides.rails.info/activerecord_validations_callbacks.html#callbacks-overview)** > > Ruby on Rails,Rails Tutorial,Ruby Basics,Rails 4,Bar Rails,Rail Then check out the dirty object feature that ActiveRecord provides and how to use it: [http://api.rubyonrails.org/classes/ActiveRecord/Dirty.html](http://api.rubyonrails.org/classes/ActiveRecord/Dirty.html) > **[\#109 Tracking Attribute Changes - RailsCasts](http://railscasts.com/episodes/109-tracking-attribute-changes)** > > Short Ruby on Rails screencasts containing tips, tricks and tutorials. Great for both novice and experienced web developers. With that said, I’d probably write an “after\_update” callback on whatever model you’re using and interrogate that object with what “model.changed”. ---
**Author:** ![blueomega](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/e95f7d/32.png) [@blueomega](https://www.ruby-forum.com/u/blueomega)\ **Post date:** [May 28, 2009, 5:41pm UTC](https://www.ruby-forum.com/t/know-what-was-updated/169013/3 "2009-05-28T17:41:28Z")
y, i´ve already updated the item model with Callbacks, the controller code was becoming ugly [http://api.rubyonrails.org/classes/ActiveRecord/Dirty.html](http://api.rubyonrails.org/classes/ActiveRecord/Dirty.html) seems to do the job [#109 Tracking Attribute Changes - RailsCasts](http://railscasts.com/episodes/109-tracking-attribute-changes) seems also a good explanation, but i cant listen here, in a library, with no phones i think its solved thx ---
**Author:** ![blueomega](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/e95f7d/32.png) [@blueomega](https://www.ruby-forum.com/u/blueomega)\ **Post date:** [May 28, 2009, 8:02pm UTC](https://www.ruby-forum.com/t/know-what-was-updated/169013/4 "2009-05-28T20:02:26Z")
That’s a great point Philip. I’m actually trying to solve that very problem in a project I’m working on. I want to be able to do exactly what lighthouseapp does when it logs ticket updates. In that case, you have comments that people can make on a ticket. But when someone updates the ticket, I want to create a comment and log who changed what. I’ve now learned you can’t do that with a simple model observer (because I need to know who is updating the ticket, which is part of the session). I searched around on this list and the only thing I’ve found with any substance is people recommending the cache sweeping recipe from the book rails recipes. I’m digging into that now… In your case though, you’re creating a separate model (AuditLog) in the controller…I want to keep this out of the controller. Do you have any experience with cache sweeping for this purpose? ---
**Author:** ![blueomega](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/e95f7d/32.png) [@blueomega](https://www.ruby-forum.com/u/blueomega)\ **Post date:** [May 28, 2009, 6:45pm UTC](https://www.ruby-forum.com/t/know-what-was-updated/169013/5 "2009-05-28T18:45:30Z")
On May 28, 2009, at 8:13 AM, JL Smith wrote: > First, get familiar with model callbacks if you’re not already because > you don’t want to put this logic in the controller: You might… the problem with the callbacks is you don’t get access to the user who did it (depending on how they’ve logged in), nor can you ignore any trivial changes – although that might not be a requirement here… Below was my solution for selectively logging actions… [http://pjkh.com/articles/2009/02/02/creating-an-audit-log-in-rails](http://pjkh.com/articles/2009/02/02/creating-an-audit-log-in-rails) -philip ---
**Author:** ![blueomega](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/e95f7d/32.png) [@blueomega](https://www.ruby-forum.com/u/blueomega)\ **Post date:** [May 28, 2009, 8:45pm UTC](https://www.ruby-forum.com/t/know-what-was-updated/169013/6 "2009-05-28T20:45:20Z")
> I searched around on this list and the only thing I’ve found with any > substance is people recommending the cache sweeping recipe from the > book rails recipes. I’m digging into that now… > > In your case though, you’re creating a separate model (AuditLog) in > the controller…I want to keep this out of the controller. > > Do you have any experience with cache sweeping for this purpose? Honestly it was long enough back I don’t remember 🙂 It might have been that I didn’t want to log all updates, only at certain times that had me keep it out of any cache/observers…