Receiving bad :dispatch value

[paolapereira93]

I am using re-graph to both mutate and query and I am facing an intermittent error in production. Here is an example:

re-frame: ignoring bad :dispatch value. Expected a vector, but got:{1 {:response {:data { ... }}}}

Here is a code similar to my application:

(defn my-callback
  "a callback"
  [_ _])

(defn- my-event
  [{:keys [db]} [_ params]]
  {:db db
   :dispatch [::re-graph/mutate {:instance-id :auth
                                 :id          (random-uuid)
                                 :query       my-query
                                 :callback    [::my-callback] ;; if callback is nil, the same error is raised
                                 :variables   {}]})

(reg-event-fx ::my-callback my-callback)
(reg-event-fx ::my-event  my-event)

I noticed that in some points of the re-graph code there are updates that could result in that error, like in here:

(update callback 1 assoc :response response)

Looking at this I can imagine why passing no callback raises the error, since (update nil 1 assoc :response {}) is {1 {:response {}}}. But I can not see how passing a callback can result in this. Also, it would be very useful to be able to omit the callback function in some cases.

[oliyh]

Hi,

What version of re-graph and re-frame are you using?

Cheers

[paolapereira93]

Here is how I am importing both:

re-frame/re-frame {:mvn/version "1.4.3"}
re-graph/re-graph {:mvn/version "0.2.0" :exclusions [re-graph.hato/re-graph.hato]}

Thank you!

[oliyh]

Thanks, I've looked into this a bit but not found anything yet. One thing I can try is to update re-frame on re-graph and run the tests to see if something changed in re-frame.

Are you using websockets or http to talk to the server?

Thanks

[oliyh]

Hi,

Are you sure you don't have a bad event handler that is wiping out the db? re-graph registers the callback against the query id, in order to dispatch it when it receives a response. If it got wiped out you'd probably see the error you get here, and that might also explain how it could be intermittent.

I upgraded most of the deps and all the tests still pass, so I don't think it's that.

Cheers

[paolapereira93]

Hi,
I am using a http server.

I reviewed my code several times. With your suggestion in mind, I noticed a point of improvement. Which was returning an empty map of effects in my callback event.

Before:

(defn my-callback
  "a callback"
  [_ _])

Now:

(defn my-callback
  "a callback"
  [_ _]
  {})

But the error continues to occur in this version. I can not see how this can wip out the db in this case, since my callback event has no effects in it.

Thanks