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javadesign-patternsmodel-view-controllerjavafx

MVP, JavaFx and components references

I've studied all popular GUI patterns - MVP,MVC,MVVM and finally I decided to implement MVP (Supervising Controller). So I have the following OBJECTS(!). Stage<-View<->Model. It's important Stage!=View, it is another object. Between view and model data binding. Besides I have a presenter(controller) which handles all events and works with view and model, so View<-ViewInterface<-Controller->Model. The problem is now how to get references to labels, textAreas etc in view. Javafx allows to use @FXML annotation to inject these components to controller. However, using MVP I need these components in View, as all logic for view is in View and I don't need them in controller. The only solution I know is:

public class MyView{
 private Button button;
 public MyView(){
  ...
  button=(Button) root.lookup("#myButton");
 }
}

That is to get references by their ID. However I don't like it. Or I do something wrong or I understand something wrong but I think a better solution exist. Please, help me to find it.

Solution

  • JavaFX has been designed to work with the MVC pattern. Hence it is much easier to use MVC than MVP. In MVP Presenter is responsible for formatting the data to be displayed. In JavaFX, it is done automatically by View. Here's a quick overview of JavaFX MVC:

    Model - the domain data / data structure that you work with in your application (e.g. Person, Employer, Coursework, etc)

    View - the UI definition of the application and its Model. The preferred way of creating a view is via an FXML file, which is essentially the View in JavaFX MVC.

    Controller - the bridge between Model and View. The code is typically isolated in XController class (where X is the name of the FXML View). The instance of Controller is automatically injected by FXMLLoader or can be done manually in case you require a custom Controller. The Controller class will have access to UI (View) elements in order to be able to manipulate different properties and also the Model, so that it can perform operations based on the UI (View) input.

    To sum up, in JavaFX you don't need to have class View, the View definition should be entirely in the FXML file. All UI elements should be injected with @FXML into your Controller class. If you absolutely have to use MVP, then AWT/Swing or MVP4j - http://www.findbestopensource.com/product/mvp4j might be a better option.

    For more detailed explanation please have a look at the official Oracle tutorial for JavaFX: http://docs.oracle.com/javase/8/javafx/get-started-tutorial/jfx-overview.htm

    If you require help building UI using FXML: http://docs.oracle.com/javase/8/javafx/api/javafx/fxml/doc-files/introduction_to_fxml.html

    This tutorial covers basics of MVC in JavaFX and how each component communicates with others: http://code.makery.ch/library/javafx-8-tutorial/part1/