database trigger and callback

rubyonrails-talk
1

If I wanted to write my own db trigger using a 'before_save" callback, how would I get the before save and after save values?

Thanks!

2

If I wanted to write my own db trigger using a 'before_save" callback,

how would I get the before save and after save values?

Thanks!

By “before save and after save values” do you mean the original, unchanged value(s) of the propert(y|ies) and the new, changed value(s)?

If so, you might be interested in #changed_attributes. If you call this on a model instance, it returns a hash where the keys are the names of the model attributes that have changed and the associated values are original values. For example:

x = User.find(1) => #<User id: 1, name: “Bill”, …> x.changed? => false x.name => “Bill” x.name = “Fred” => “Fred” x.changed? => true x.changed_attributes => { “name” => “Bill” } x.save => true x.changed? => false x.changed_attributes => {}

For more information:

3

I'm now following this method - using a callback to log the changed attributes in my audit table for the model.

The only thing is, I'd like to grab the name of the logged-in user and save it in the audit table. Is there any way of doing that? I can get it in the controller, but not in the model by using current_admin_user.login