Prompting the user before exiting with unsaved changes

[alfongj]

If there are unsaved changes, we should prompt the user if he wants to save them, when he clicks to close the browser window.

If it is possible to communicate back which flash in that moment, this could be useful for detecting when the user closed the window on purpose (therefore, eliminating the autosave copy) and when it was closed without user interaction (therefore conersving the copy).

[alfongj]

This tutorial can be useful

[alfongj]

Done using a function inside builder.jsp which runs at the onbeforeunload (when the browser window is closed) event, which calls FileManager.askBeforeExit(). This function eliminates auto-saved trees, and tells the javascript calling function that it should prompt the user if he wants to continue in the web, if there are unsaved changes in the file.