window.locationworks fine, but returns me the whole, absolute path, like http://domain.xyz/punch/lines. But I only need http://domain.xyz/. How can I extract only that first part? And how can I make that dynamic, I mean to be always the same even when the subdirectory path gets longer?
You can get the protocol and the host separately, and then join them to get what you need
window.location.protocol + "//" + window.location.host + "/"
As a sidenote, window.location.pathname would contain the path.