riverpod conditional provider state updates

Question

I'm porting my app to river_pod, it's been great so far but I always stumble upon the same problem. There is some situations where I need a provider to update its state only conditionally depending on the new value acquired by the ref.watch .

An example of this is my last road-block:

I have a ChangeNotifier provider that exposes the current user location. This provider is listened to by multiple other providers. One of them is a FutureProvider that fetches the trending posts nearby every time the location changes. The problem here is that this location updates very frequently (every 10s or so) so this fetch is done a very unnecessary amount of time.

What I would like to do in that situation is, in this FutureProvider, be able to get the new position but update only conditionally (here the condition being, if the last fetch was done more than 1km away) to avoid this unnecessary network call and all underlying UI updates it causes.

This implies two things, having access to the last state to make the comparison, and be able to cancel an update (because here even if I don't do the fetch and return the last value, the UI will still read that as an update).

I understand that those mechanisms are not built-in, so I was wondering, was is the river_pod way to approach this problem?

Cheers!

Answer 1

I was having same problem to solve. I had to compare old data and new data and change the state in provider only if there is a change.