If I wanted some computed value (a level 3 subscription) in an event handler, can I subscribe in the event in the event handler, or should I put re-frame/subscribe in a cofx handler, OR do I have to do it as an argument to the event handler (in the view)

A third alternative would be to make the computation a separate function that can be called by both the reg-sub and by the event handler. If it’s a time-consuming computation, though, I’d probably use one of the two alternatives you mentioned, with probably a slight preference for putting it as an argument in the event vector, on the grounds that it’s probably simpler that way.

If I understand the question the problem can be solved with an interceptor, where you can get value from db which in turn should have a coeffect that you pass to your event handler.

I just put it in a re-frame/reg-cofx

thanks for the help guys!

;; DB
(reg-fx
:computed-val
(// do whatever you want with the vallue in db))
;; events
(def your-interceptor
(re-frame.core/->interceptor
:before (fn [context] 
(let [computed-val (get-in context [:coeffects :event :computed-val ])]))))

(reg-event-fx
:your-event-handler
[your-interceptor]
{:db db
:set-computed-val-coeffect})

I dont think that applies to my situation, but it is an interesting pattern, thanks!

:thumbsup:

What’s your favorite way to debug an http-xhrio event-fx whose :on-success isn’t firing? The network call returns a success and I see return data from the endpoint, but the :on-success isn’t dispatched and nothing shows up in the event trace (using fn-traced)

:on-failure doesn't work either?

Not that I’ve seen, I was just in the process of shoving in some print statements, I’ve been relying on re-frame-tracing tool but maybe one is firing and the tracer isn’t catching it (seems unlikely)

I would probably use an interceptor to print out whatever is happening on the event call

Well damn, looks like the failure dispatch is firing but not showing up in the trace

Just when I was starting to trust the tooling! 😄 Figures

That's weird, but in :after you should be able to see what's happening, or if you use 10x there might be some info

fn-traced FTW!

Oh wait, that's locally defined 😊

Let's see, we cribbed that from re-frame-10x, though IIRC. looks

See https://github.com/Day8/re-frame-10x/blob/master/docs/HyperlinkedInformation/EventCodeTracing.md

Yeah I’m using 10x with fn-traced but it’s not reliably reporting resulting dispatches from http-xhrio event-fx… I somehow got it to show the failure dispatch but then couldn’t reproduce that. Weird!

I’ve explored the trace through :after too and nothing

Is there anything happening in Network tab of the browser?

Oh, sorry, you mentioned it

Maybe worth to reload something like repl, and maybe everything

Yeah I built the repl back up with fresh everything. Weirdness. I’ll keep tinkering

Thanks!

Weird.

@b2berry is it possible that your handler fn's got the wrong arity?

I don’t think so, I injected print statements in them so I know they are firing now, just not seeing them in fn-traced

Cool. Very weird, I've definitely gotten to the point of trusting 10x pretty well.

Yeah me too this is the first time it’s had a hiccup for me. I’m a novice with web-development plumbing so who knows what I’ve messed up (and maybe it’s not me, but I’m going to say it probably is 😄 )

@thmorriss there's an FAQ to answer your question

@mikethompson thanks!

@thmorriss https://github.com/Day8/re-frame/blob/master/docs/FAQs/UseASubscriptionInAnEventHandler.md

@b2berry be sure to do a lein clean too. In my experience, it can sometimes fix the most intractable problems