and those elements will trigger elements in next level.

It is a three levels hierarchy so to speak.

but each element will send an ajax request when selected.

Those requests will become out of control especially when I repeatedly click the root element.

Can I queue those XHR request in a queue and send them one by one?

or maybe add a delay before send so that they can collect their information into one batch request and send one request after that.

Please advice. Thank you very much.