While Active Resource still seems to be lightly maintained, I’m wondering why there doesn’t seem to be much use of it. At a certain scale / complexity, a centralized application for certain core functions like 37signals’ Launchpad or Shopify’s accounts.shopify.com might make scene in some cases, and I imagine AR would fit for internal integrations like that as opposed to managing multiple sets of database configurations, credentials, etc. Is this typically what’s it’s used for? If not, what is?
My recollection of it was that it was meant to allow you to wrap around something like another app, or an API somewhere, and have the result quack like an ActiveRecord.
The original implementation happened before ActiveModel was a thing, and the whole refactor around the difference between a Model and an ActiveRecord. (Original Gangster Rails considered ActiveRecord – alone – to be the M in MVC.)
I suspect that one of the reasons ActiveResource was taken out of the core was to simplify the lift of that separation.
Another might be that ActiveRecord sets the developer expectations quite high when it comes to performance, the need (or lack thereof) to cache things, etc. If you reference two objects in a view, and one of them has to go through two oatmeal boxes and some twine, you’re going to have a bad day, performance-wise, unless you’ve planned for that. ActiveResource made them look too much alike, and might lead you to some bad decisions.
All just my supposition…
Walter