ahooks/es/useRequest/src/utils/subscribeFocus.js

react hooks library

// from swr
import isBrowser from '../../../utils/isBrowser';
import isDocumentVisible from './isDocumentVisible';
import isOnline from './isOnline';
const listeners = new Set();
function subscribe(listener) {
    listeners.add(listener);
    return function unsubscribe() {
        listeners.has(listener) && listeners.delete(listener);
    };
}
if (isBrowser) {
    const revalidate = () => {
        if (!isDocumentVisible() || !isOnline())
            return;
        listeners.forEach((listener) => listener());
    };
    window.addEventListener('visibilitychange', revalidate, false);
    window.addEventListener('focus', revalidate, false);
}
export default subscribe;