@restart/hooks/cjs/useRefWithInitialValueFactory.js

A set of utility and general-purpose React hooks.

"use strict";

exports.__esModule = true;
exports.default = useRefWithInitialValueFactory;

var _react = require("react");

var dft = Symbol('default value sigil');
/**
 * Exactly the same as `useRef` except that the initial value is set via a
 * factroy function. Useful when the default is relatively costly to construct.
 *
 *  ```ts
 *  const ref = useRefWithInitialValueFactory<ExpensiveValue>(() => constructExpensiveValue())
 *
 *  ```
 *
 * @param initialValueFactory A factory function returning the ref's default value
 * @category refs
 */

function useRefWithInitialValueFactory(initialValueFactory) {
  var ref = (0, _react.useRef)(dft);

  if (ref.current === dft) {
    ref.current = initialValueFactory();
  }

  return ref;
}