I have looked into this. The problem is that any type of user themed confirmation prompt is asynchronous. But the browser built in version actually blocks code execution. In the places that TiddlyWiki needs a confirmation it depends on that code blocking. In other words the need to use the browsers built in confirm dialog is deeply embedded in the TW code and would require significant work to change the core design and support asynchronous user input.
Sadly, I don't think Jeremey nor any of the contributors are up to the task with everything else going on. But one could dream because I would love this feature. -- You received this message because you are subscribed to the Google Groups "TiddlyWiki" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/tiddlywiki. To view this discussion on the web visit https://groups.google.com/d/msgid/tiddlywiki/35c016d2-c29d-4559-b30b-7432833eacdb%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.

