useChangeObserver

import { useChangeObserver } from "@prestojs/util";

useChangeObserver(value,onChange,?options)

Call a function whenever a value changes.

This works by monitoring a value passed in and tracking it's last value. Whenever the value changes the provided callback will be called with the last and current value.

export default function Example() {
  const [count, setCount] = useState(0);
  useChangeObserver(count, () => {
    console.log(`Changed from ${prev} to ${next}.`));
  }
  return <>
    Count: {count}
    <button onClick={() => setCount(c => c+1)}>+1</button>
  </>;
}

	Parameter	Type	Description
*	value	T	The value to monitor for changes. This can be any type but for complex types you will need to provide your own `isEqual` function. For simple shallow comparisons the default function will suffice (eg. it will compare each element in an array or each value on an object 1 level deep).
*	onChange	Function	The function to call when `value` changes. This is passed the previous value and the current value.
	options.disabled	boolean	If true then no changes will be detected. When this changes from true to false the callback won't be called until the next change in value. This is useful for disabling the callback when no value is yet available eg. when waiting for first response from an API.
	options.isEqual	Function	Function to determine equality between items. If not provided the default will do shallow equality checks with specific support for an `isEqual` function on objects (eg. if an object implements `isEqual` it will be called instead of doing any other comparisons. This is supported by ViewModel.

Returns

void

Has no return value