We are developing a Smart Home Dashboard. When the component mounts, we fetch the current 'Thermostat Temperature' from the server and set it to a local React state. We also have a requirement to 'Sync' the temperature back to the cloud whenever the user changes it using a slider.
If we use a standard useEffect to watch the temperature state, the app will fire a 'Sync' request the moment the data arrives from the server during the initial mount. This creates redundant network traffic and potential data conflicts.
The Challenge: How would you implement a custom hook, useUpdateEffect, that allows us to trigger an effect only on subsequent updates (when the user interacts with the slider), but strictly ignores the initial mounting of the component?