@wordpress/edit-post/build-module/components/editor-initialization/utils.js

Edit Post module for WordPress.

/**
 * Given a selector returns a functions that returns the listener only
 * if the returned value from the selector changes.
 *
 * @param  {Function} selector Selector.
 * @param  {Function} listener Listener.
 * @param  {boolean}  initial  Flags whether listener should be invoked on
 *                             initial call.
 * @return {Function}          Listener creator.
 */
export const onChangeListener = (selector, listener, initial = false) => {
  let previousValue = selector();

  if (initial) {
    listener(selector());
  }

  return () => {
    const selectedValue = selector();

    if (selectedValue !== previousValue) {
      previousValue = selectedValue;
      listener(selectedValue);
    }
  };
};
//# sourceMappingURL=utils.js.map