Is there something like Thread.local in Marten?

[adb819t]

As per succinctly explained in this article, there are times we want to know who's making some changes to the data. In Rails, we can use Thread.local and store user information there, to later be retrieved from the model just fine. Is there similar or equivalent mechanism in Crystal/Marten? Otherwise, we'll have to always define performer property and then set it out from the route/controller.

I guess there's no other way, but I just want to ensure and discuss, out of my limited knowledge. Thanks :)

[adamnoto]

Rails also wrap Thread.current and Thread.local into readily usable primitive: ActiveSupport::CurrentAttributes. But yeah, it starts with Thread.current or things similar to that first.

[ellmetha]

Hey! I remember you asked a similar question a few months ago: #310
The answer in this other discussion is still relevant here: there is no equivalent to Thread.local in Crystal. You can try adding properties to fibers as mentioned in the other discussion, but I don't think that this is a good practice tbh.

[adb819t]

Ah yes. My bad... got it.

[adb819t]

So... meaning Marten is Fiber-based. How shall we set it from middleware/controller and get it from the model? 🤔 sorry so new here. Thanks.

[ellmetha]

You can access the current fiber with Fiber.current. Assuming you open Fiber to add properties (as highlighted in #310), then all you have to do is implement a custom middleware and mutate the current fiber as intended.

[adb819t]

I see, I got it. That's super helpful.