Issue collection that may need a big refactoring of the FXML loading process

[manuel-mauky]

This issue should be used to gather other issues and ideas that can't be implemented with the current FXML loading mechanism.

At the moment we are wrapping javafx's FXMLLoader when we load our Views. But maybe this approach isn't sufficient because the FXMLLoader isn't implemented in a modular way and don't provide hooks to modify or configure the live cycle and loading process.

Therefore a possible workaround would be to fork the FXMLLoader and provde our own extended FXMLLoader. Of cause this would have many negative impacts like the effort of porting back upstream bugfixes into our version. Another downside is the usage of private APIs in the FXMLLoader that won't be available for us with Java 9.

This issue can be used to discuss other solutions and a general architecture of a more flexible loading process.

Issues that are effected:

• Injection of nested ViewModels #215
• automatic ResourceBundle loading? #207
• Can't access Viewmodel after Include. #190
• Make it possible to register custom BuilderFactories #131
• Injection of root element #236
• No exception when fx:controller points to wrong codebehind class #433