ref.listen + execute setState within the body of listen vs just ref.watch

[IoannisChadjiminas]

Hello,

I would like to ask whether is good practise to execute setState within the body of ref.listen instead of executing ref.watch. I have a case where I don't want to execute ref.watch but just ref.listen and then execute setState within it.

Regards,
John

[daniellampl]

It depends on why you would like to call setState in the ref.listen callback instead of using ref.watch. If you only want your UI to update if the provider's state matches a specific condition, I would use .select to explicitly listen to state changes that are matching a given condition, like so:

final bool roomCapacityReached = ref.watch(peopleCountProvider.select((int peopleCount) => peopleCount >= 250));

This will only update the widget if roomCapacityReached changes, instead of whenever the state of the peopleCountProvider changes.