Rails Observer Alternatives for 4.0

Question

With Observers officially removed from Rails 4.0, I\'m curious what other developers are using in their place. (Other than using the extracted gem.) While Observers were cer

Answer 1

Using active record callbacks simply flips the dependency of your coupling. For instance, if you have modelA and a CacheObserver observing modelA rails 3 style, you can remove CacheObserver with no issue. Now, instead say A has to manually invoke the CacheObserver after save, which would be rails 4. You've simply moved your dependency so you can safely remove A but not CacheObserver.

Now, from my ivory tower I prefer the observer to be dependent on the model it's observing. Do I care enough to clutter up my controllers? For me, the answer is no.

Presumably you've put some thought into why you want/need the observer, and thus creating a model dependent upon its observer is not a terrible tragedy.

I also have a (reasonably grounded, I think) distaste for any sort of observer being dependent on a controller action. Suddenly you have to inject your observer in any controller action (or another model) that may update the model you want observed. If you can guarantee your app will only ever modify instances via create/update controller actions, more power to you, but that's not an assumption I would make about a rails application (consider nested forms, model business logic updating associations, etc.)