Using JavaScript Promises with CLOG (advanced)

[rabbibotton]

So as most know using javascript with CLOG is fairly easy, you just use the functions js-execute or js-query when a result desired. However "modern" javascript frequently uses promises. So here is a tip on how to use them:

So lets say I setup a panel with two controls a file picker and a button

I set an event on the panel in code or in on-create
(set-on-event-with-data panel "result" (lambda (obj data) (print data)))

In the on-click or some place else, I request the contents of the file picker file which returns a promise of the text of the file. I use .then in JS with a call to trigger to then trigger the custom even "panel":

(js-execute target (format nil "~A[0].files[0].text().then(function(r){~A.trigger('result',r);})" (jquery (file-control panel)) (jquery (file-control panel))))

In general using custom events (set-on-event or set-on-event-with data) are the best way to work with JS's model of async programming.