Widget Ajax - js .onclick button

In reference to the Widget and ajax. I don’t need it to auto reload (make calls at a set amount of secs.)
What I would like to do is refresh the widget with ajax via an javascript .onclick function invoked by a button on the page.
So, would this be possible if time is set to 0 (zero).. and then widget ajax reload on a .onclick from button OR maybe another js event? (I can create the function in functions.php if needed)