I know there's a separate StackExchange site for user experience, but I was wondering if questions related to user interface (not necessarily code, although code might be mentioned) are appropriate to ask on StackOverflow. Specifically, is it okay to ask more "opinion-based" questions about what the user interface should be for a specific web-app I am designing?
So I'm currently designing a web app that involves the user interacting with input boxes, etc. I don't want the user to lose their data if they, for example, close the page by accident, but I also don't want them to be annoyed by popup boxes asking them if they are sure they want to leave the page. I'm considering making it so that the popups only occur when the user closes the tab after interacting with something on the page, similar to what Gmail does, but this would involve a lot of changes to my code and I'm wondering if anyone else has any otther lightweight, more elegant suggestions?