fx:classParameters attribute
The fx:classParameters
attribute specifies the constructor parameters of the generated class. If omitted, the generated class has a parameterless constructor.
The fx:classParameters
attribute can only be set on the root element.
Usage
<BorderPane xmlns="http://javafx.com/javafx" xmlns:fx="http://jfxcore.org/fxml/2.0"
fx:classParameters="String, MyClass<Double>">
</BorderPane>
In XML files, the < character can only be used as a markup delimiter, and must be escaped using < in attribute text. However, the FXML 2.0 compiler accepts the non-standard literal form for better code readability.