[knewter]

Sorry for copy-pastaing my reddit comment on this same article, but I think it's relevant to your point.

--- I feel very strongly about this, and I agree entirely. I think projects should go one step further. For something like forem, I think it makes sense to have a gem called forem_auth, and for the installer to give you an option to install the engine as a standalone app. If you choose to, it would include the forem_auth gem in the Gemfile, and you'd get auth built in. Otherwise, you configure it for your own auth.

I think refinery and spree should adopt identical stances to forem in this regard. I also plan to take this a bit further in all of my engines going forward, and defer the persistence decision entirely, making it trivial to switch out ActiveRecord or mongoid or csv files or whatever. Experimenting with this on internal apps presently, and it shows comically awesome amounts of promise.

I think it's a relatively normal thing for lispers to defer decisions like that until they no longer have to decide - that's what we've been doing. ---

I've been thinking about rails engine interoperability for quite a while, as have the spree/refinery/other forem guys, and I've got a very solid mental model of what it needs to be to make plug-and-play a possibility with these style components. It is definitely within reach, and we need some other people to get on board with these ideas to make it the obvious choice for future engine makers.