Right. alert/confirm/prompt are passed to callbacks registered with WebEngine. The reason is that applications may want to handle these calls in different ways: display a dialog box, an overlay sheet, print a console message etc -- so WebEngine delegates the task to client code. However, we should probably add a default implementation for these callbacks once the Alert class is ready.
Yes, I have the same question. For the prompt dialog, I wants to get the prompt dialog and let use input value. Then I got the value. But currently JavaFX seems can't popup the prompt dialog. How can do this?