useWatch$() to execute a function before the initial render and whenever the tracking values change. The function executes before rendering, but it can't delay rendering, so if
useWatch$() is asynchronous, the rendering will happen before the
useWatch$() is fully executed.
Tracking store changes
useWatch$() hook receives a
track() function used for setting up subscriptions that will automatically rerun the
useWatch$() hook. The set of
track() properties resets on each
useWatch$() execution, therefore it is important to always use
track() to set up subscriptions anew. Because of this it is possible for the
useWatch$() to subscribe to different properties over time.
useWatch$() hook can return a cleanup callback. This is useful for cleaning up any resources before new execution.