Dependent execution

[StorytellerCZ]

I was recently looking at React Query and found in their docs that they have something called dependent queries: https://tanstack.com/query/latest/docs/framework/react/guides/dependent-queries

I found this very interesting and something that I often find myself needing with the hooks, especially as it relates to user based content where I don't want to trigger a subscription and everything else if the user is not logged in or at least until that data is available. This could also be used with other conditional data and could help in reducing lot of boilerplate code to handle such scenarios or wait with execution until the given data is available so that I don't have a flash of 404 page and similar issues.

[radekmie]

Do you have anything in particular in mind? For example, useSubscribe already supports it, since the name (1st argument) is optional, and there's no subscription made if it's undefined.

[StorytellerCZ]

Interesting, that can be a workaround for the subscribe:

const userId = useUserId()
useSubscribe(userId ? undefined : 'get.profile')

But even with this the useFind or useTracker that follows would still execute, so it would be nice to prevent that if the condition isn't met.

[radekmie]

useFind also supports that via undefined and null in the result of the first argument. And useTrcker can just do an early return. Sure, there’s no extra prop, but it’s clear when read (I see and use it often).

[StorytellerCZ]

I'll experiment with it a bit and then I think we can add that to the documentation or guide.