GoScrobble/web/node_modules/@restart/hooks/cjs/usePrevious.js

31 lines
678 B
JavaScript

"use strict";
exports.__esModule = true;
exports.default = usePrevious;
var _react = require("react");
/**
* Store the last of some value. Tracked via a `Ref` only updating it
* after the component renders.
*
* Helpful if you need to compare a prop value to it's previous value during render.
*
* ```ts
* function Component(props) {
* const lastProps = usePrevious(props)
*
* if (lastProps.foo !== props.foo)
* resetValueFromProps(props.foo)
* }
* ```
*
* @param value the value to track
*/
function usePrevious(value) {
var ref = (0, _react.useRef)(null);
(0, _react.useEffect)(function () {
ref.current = value;
});
return ref.current;
}