How to hook into model attribute changes?

rubyonrails-talk
1

Hi John

Hi,

What's the best way to hook into any changes made to the value of a single model attribute? I need to know when the encrypted_password attribute on my User model changes i.e. when the user has changed their password. I'm not interested in the actual changed value, I just need to know when it's been changed so that I can regenerate their API key as well.

cch: You should look into callbacks. For example, I use

  def after_update(record)     log(record, "UPDATE")   end

to record whether a change has been made

2

You could try using this plugin and a callback (after_update maybe?) to determine when to regenerate the API key:

http://svn.viney.net.nz/things/rails/plugins/acts_as_modified/README