Nwjs Updating Progress Bar During Long Loop Javascript

I'm having some troubles with javascript. I'm trying to do a desktop app with NW.JS. I have a .xml file which I drag and drop in my app then it run a function to read the XML do so

Solution 1:

After trying the same code in NWJS and Electron, I found the problem to be that any long-running process in the 'main' Chromium process blocks rendering. The solution is to spawn a child process that communicates via Node's IPC. More details in this answer.