NPE in initialize - javafx-2

Question

After reading introduction_to_fxml I got an impression that an initialize method can be used as spring's afterPropertiesSet or EJB's a #PostConstruct method - that is expected all member variables set when it is invoked. But when I tried I got NPE. The code I tried looks like following.
Main app:
public class MyApp extends Application {
#Override
public void start(Stage stage) throws Exception {
Parent root = FXMLLoader.load(getClass().getResource("/myapp.fxml"));///MAIN LOAD
Scene scene = new Scene(root, 320, 240);
scene.getStylesheets().add("/myapp.css");
stage.setScene(scene);
stage.setTitle("my app");
stage.show();
}
public static void main(String[] args) { launch(); }
}
myapp.fxml:
...
<VBox fx:id="root" xmlns:fx="http://javafx.com/fxml" >
<ControlA>
<SomeClass>
</SomeClass>
</ControlA>
</VBox>
ControlA.java:
#DefaultProperty("aproperty")
public class ControlA extends StackPane {
private SomeClass aproperty;
public ContentPane(){
try {
FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("/controls/ControlA.fxml"));
fxmlLoader.setRoot(this);
fxmlLoader.setController(this);
fxmlLoader.load();//ControlA LOAD
} catch (IOException exception) {
throw new RuntimeException(exception);
}
}
public void initialize() {
//aproperty is null here, called from ControlA LOAD
}
//aproperty get/set
public void setAproperty(SomeClass p){//it is called from MAIN LOAD
....
}
The component's initialize method is called from its load method and its property is being set from parent's load method which is called later. And it looks understandable, a component's property values can't be constructed until parent fxml is read. But if so, what is best practice to init a component before it will be used and after all the props were initialized?
Best regards, Eugene.

Answer 1

You need to implement the Initializable interface in a controller. I was under the impression that this was for controllers only.