I am building my first electron desktop app. It creates a formatted document/book from spreadsheet data to either be printed or made into a PDF. I am trying to figure out the best way to prevent performance loss from reflow/repaint when having a large document(lots of divs). I have found that if I have the book in an iframe then I do not suffer reflows/repaints from UI changes and can control when to have it loaded. If I try to create a PDF however I will only get the amount of the iframe that is visible.
Simply, I'm looking for the best solution to prevent reflow in a complex HTML element while still being able to print it to PDF.
I've found a solution to the problem.
As far as I understand, for an electron desktop app, that is not running a server, you cannot directly access myIframe.contentDocument on elements for actions such as append, innerHTML, or offsetHeight etc. The only thing you can do is contentDocument.write(), however once you have used this method, you have access to all of the other regular DOM methods. The best I can understand is that when you use contentDocument.write() it essentially creates a virtual HTML document. This is my workaround at the moment which is working like a charm in giving me control over what elements reflow and what ones do not.
Hope this helps anyone dealing with the same issue.