[SOLVED] Can I avoid making a synchronous callback, if I want a click to only *sometimes* open a new window?

Can I avoid making a synchronous callback, if I want a click to only *sometimes* open a new window?

In this scenario:

User enters some information into a textbox
User clicks a button
Server-side processing of the entered information takes place
Depending on the result of that server-side processing, either a new window is to be opened, or a message is to be displayed on the current page (and no popup)

I cannot come up with an approach other than to use async: false in the jQuery ajax call, which is strongly discouraged:

Setting this option to false (and thus making the call no longer asynchronous) is strongly discouraged, as it can cause the browser to become unresponsive.

I've tried:

having the call be async and in the callback handler, depending on what the server said, sometimes opening a new window - this gets blocked by popup blockers
another idea, which I've not even bothered with due to its unpleasantness, is to always open a window, and it is this new window that calls the server, and sometimes closes itself (somehow updating text in the parent on its way out)

What I've settled on is what I've described above: in the click handler, do a synchronous server call, and if the server says to do so, open a new window. Popup blockers are happy with this, because the window opening is done in the click handler. But...

Similar (but not duplicate, as I don't always want to open a new window) questions that have not provided a nice solution:

Solution

I tried out my 'unpleasant' idea: to always open a new window, and have that new window make the server call, closing itself if the results of the server call dictated that it was not required.

But that was pretty horrible, so I stuck with the synchronous call.

So for me, the answer to this question is no, you can't avoid being synchronous in this situation.