iterami/Docs.htm/common HTM Repos/core.js/core_handle_beforeunload(event)

• Calls "core_events.beforeunload(event)" if it exists, which allows repos to conditionally determine when to "event.preventDefault()".
• Can be used to ask for confirmation before the user leaves the page.
• Can be used to automatically core storage_save(args) when the user leaves the page for repos with continual progress.