let data; function getConfig() { if (data) return Promise.resolve(data); return fetch("/config.json?nocache=" + new Date().getUTCMilliseconds()).then(function (response) { data = response.json(); return data; }); } export function enableMultiServer() { return getConfig().then(config => { return config.multiserver; }).catch(error => { console.log("cannot get web config:", error); return false; }); }