function waitFor(selector, callback, timeout) {
const element = document.querySelector(selector);
if (element) {
callback(element);
} else {
if (timeout) {
return window.setTimeout(() => {
return window.requestAnimationFrame(() => {
waitFor(selector, callback);
});
}, timeout);
}
return window.requestAnimationFrame(() => {
waitFor(selector, callback);
});
}
}
new Function( argument1, argument2, implementationString )
типа такого.