Can you elaborate on your case? You could: 1. transact! from the result-action 2. Use state-machines

I'm confused. The code uses append-to and you say that works. So to relocate your problem we need to change that to replace-at? Is tab/ids a single thing or a vector? (In the latter case :what are you trying to do? Do you need to add also an index to ur replace at vector?)

Hey. Sorry about the confusion. :tab/ids is a vector of {:tab/id "<some-id>"}. So the workflow is this: when Main is loaded it will send a query to fetch all the tabs from the server (hence why the df/load in :will-enter uses append-to since at this stage there are no tabs stored locally yet) Now at some point I want to be able to refresh my data, hence why there's a button that will load all the tabs again. But in this case, because I already have all the old tabs stored from the previous load, I want to be able to replace all of them with the new data.

I hope that makes sense.

I see. You are sure the load is happening and returned the data you expected? Try to change the replace at location to something else, eg end with :tab/ids2 - will it appear there?

Hey. Yep the data is loaded correctly. I checked both via Network and the DB as well. The tabs are normalised into their respective table correctly. It's just for some reason I can't replace the edges. I'll give :tab/ids2 a go tmr 🙂

Hey so I tried it. No luck. The edges still aren't being replaced 😞

So you changed the replace-at vector to end with :tab/ids2 but the data is not placed under that key? What if you change the vector to just [:tmp-test/tabids] ? Perhaps st. is wrong with the replace-at syntax? What id you do merge or merge-component instead, does it work there?

Ok, I managed to replicate it... 👀

Noteworthy: if you remove the will-mount load, then the on-refresh load works as expected. So it is not wrong per se.

If I change the refresh load to :target (targeting/replace-at [:component/id ::main :tab/ids2]) then it DOES work and sets tab/ids2 in the Main component

interestingly,

(merge/merge-component!
    
    TabHeader
    [{:tab/id 5 :tab/name "Home 3"} {:tab/id 6 :tab/name "Details 3"}]
    :replace [:component/id ::main :tab/ids])

FYI at the end of load! , finish-load! is called which again calls

(targeting/process-target <current state map>
      :tab/ids [:component/id :com.example.ui/main :tab/ids])

But when I log its output state when triggered by the button then it seems to have done nothing.

I think I see the problem - replace-at seems to DO NOTHING of the target is a vector (you expect it to replace it whole but it only supports prepending / appending to it). See here: https://github.com/fulcrologic/fulcro/blob/develop/src/main/com/fulcrologic/fulcro/algorithms/data_targeting.cljc#L142

@U0CKQ19AQ is ☝️ correct, i.e. replace-at cannot replace a whole to-many property such as :tab/ids [[:tab/id 1] ...] ? I guess the solution would be to add a custom post-mutation that first clears the target property and then applies the normal behavior (which will work for a nil property)

@U013F1Q1R7G a simple solution: `{:target (targeting/replace-at [:component/id main :tab/ids])}` -> {:target [:component/id ::main :tab/ids]} i.e. don't use replace-at

seems an oversight to me

I don’t remember any special case that would make using a replacement on to-many not work right…I think I just missed the case

I can send a fix PR

@U0522TWDA hey sorry for not getting back to you sooner. Somehow when I was testing against both tab/ids and tab/ids2 there were no changes to the state map at all despite transactions were being sent and responded properly. May be I've mucked up somewhere along the way 😅 I'll give {:target [:component/id ::main :tab/ids]} a go when I'm back to my main PC. Thanks a lot for going to the bottom of this! I really appreciate it 🙂

Also I'm a bit confused as to how removing the will-enter load makes the refresh load work again.

In my mind, the workflow is pretty simple: User load Main -> fetch, load and merge data before entering -> user manually refreshes data -> (here I'd expect it's exactly the same as before:) fetch, load and merge data.

Simply: it works if the target is nil

https://github.com/fulcrologic/fulcro/pull/511

@U013F1Q1R7G Tony has release the fix that will make replace-at work for you in Fulcro 3.5.15 so switch to that

@U0522TWDA @U0CKQ19AQ Thank you so much for the help 🙂 I'll give it a go this evening.

there is no such thing as “concurrent” in Fulcro client-side space. Those two clicks will run sequentially. Guaranteed. The mechanism doesn’t “debounce” your requests, as that makes no sense. You asked for it. Fulcro does it. Idempotence or using a debouncer is your answer.

(goog functions has a debounce)

Fulcro cannot do it, it is very use-case specific. In some apps, running the same mutation twice in a sequence is fine (e.g to increase a counter as in the Book). As Tony suggests, if it is not ok for you, use debounce or make the mutation set some toggle to let it know to ignore subsequent calls.....

have no idea what you mean. React hooks are a React feature. Fulcro has nothing to do with them.

If you mean “can I choose to have them change?“, see the React docs

If the answer to my “interpretation” is “yes”, see arity 2

If your question is instead “Can I get them to change after a source code hot reload”, then the answer is probably “no”…unmount/remount the component will do it, and you could change the react key on the component to cause that.

As a hack, you could add a hook to hot reload that simply increments a global atom holding an int, and include that int in your dependency list for use-memo:

(use-memo (fn [] ...) [@hot-reload-counter])

@U0CKQ19AQ Yes, I meant the latter. And the "hack" is exactly what I needed.

thx for sharing!