rc-hooks
Version:
React Hooks Library.
27 lines (26 loc) • 833 B
JavaScript
// from swr
import { isDocumentVisible, isOnline } from './dom';
var listeners = [];
function subscribe(listener) {
listeners.push(listener);
return function unsubscribe() {
var index = listeners.indexOf(listener);
listeners.splice(index, 1);
};
}
var eventsBinded = false;
if (typeof window !== 'undefined' && window.addEventListener && !eventsBinded) {
var revalidate = function () {
if (!isDocumentVisible() || !isOnline())
return;
for (var i = 0; i < listeners.length; i++) {
var listener = listeners[i];
listener();
}
};
window.addEventListener('visibilitychange', revalidate, false);
window.addEventListener('focus', revalidate, false);
// only bind the events once
eventsBinded = true;
}
export default subscribe;