Subscription usage

[devnaumov]

Hey! I have a few questions about using the onChange method. Does state automatically handle the unsubscribe logic, or do I need to call it manually, for example, from useEffect on component unmount? Also, is it okay to subscribe to certain state changes? For instance, if I have activeTodo: 1, I want to run some effect when activeTodo has changed, like this: todoStore.activeTodo.onChange(someLogic). Or there better alternatives?

[DawidWraga]

Hey @devnaumov , thanks for your questions. I will improve the docs to make this clearer.

Is it okay to subscribe to certain state changes? For instance, if I have activeTodo: 1, I want to run some effect when activeTodo has changed, like this: todoStore.activeTodo.onChange(someLogic)

Yes, using todoStore.activeTodo.onChange(someLogic) is perfectly fine, assuming that activeTodo is state.

Currently, computed values don't have the onChange method, but I'll consider adding it in the future.

Does state automatically handle the unsubscribe logic?

If you are using createStoreContext, the Provider component automatically unsubscribes from all store effects when the component is unmounted.

It is best practice to always call onChange inside effects, as it ensures the onChange logic is called on the right store instance and can be unsubscribed from correctly.

If you are using a global store, there is no automatic unsubscription. I'm not sure if this is possible or desirable - please let me know if you have any ideas on why or how this could be implemented.

For more details on how onChange and effects work together, please refer to the updated onChange and effects documentation.

(I will update the docs now, it should be live shortly)

[devnaumov]

Thanks for the clear explanation!