JavaFX 2 and Internationalization

Question

I've just started writing my first JavaFX 2 application after learning the basics and would like to internationalize it.

I notice that in JavaFX 1.x, the scripting language allowed for very simple internationalization of strings. Are there any similar features in JavaFX 2?

Basically: what is the best practice for internationalizing a JavaFX 2 application?

Answer 1

The basic steps (among others) of a java app internationalizing, are Localelizing and resource bundling. In JavaFX, you can use FXMLLoader#setResources() for that purposes. Here a SSCCE demo to demonstrate it. The codes are self-descriptive.
Demo package structure:

bundledemo
    |------ BundleDemo.java
    |------ MyController.java
    |------ MyView.fxml  
bundles
    |------ MyBundle_en.properties
    |------ MyBundle_kg.properties

MyBundle_en.properties

key1=Name Surname
key2=How are you?

MyBundle_kg.properties

key1=Aты Жөнү
key2=Кандайсың?

MyView.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.layout.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.*?>

<BorderPane fx:controller="bundledemo.MyController" xmlns:fx="http://javafx.com/fxml">
    <top>
        <!-- This label's text will be set by the controller -->
        <Label fx:id="lblTextByController"/> 
    </top>
    <center>
        <!-- This label's text will be taken from the bundle automatically -->
        <Label text="%key2"/>
    </center>
</BorderPane>

MyController.java

package bundledemo;

import java.net.URL;
import java.util.ResourceBundle;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Label;

public class MyController implements Initializable {

    @FXML private Label lblTextByController;
    private ResourceBundle bundle;

    @Override
    public void initialize(URL location, ResourceBundle resources) {
        bundle = resources;
        lblTextByController.setText(bundle.getString("key1"));
    }
}

BundleDemo.java

package bundledemo;
// imports are ignored.

public class BundleDemo extends Application {

    private Stage stage;

    @Override
    public void start(Stage primaryStage) {
        stage = primaryStage;
        Button btnEN = new Button();
        btnEN.setText("English");
        btnEN.setOnAction(new EventHandler<ActionEvent>() {
            @Override public void handle(ActionEvent event) {
                loadView(new Locale("en", "EN"));
            }
        });

        Button btnKG = new Button();
        btnKG.setText("Kyrgyz");
        btnKG.setOnAction(new EventHandler<ActionEvent>() {
            @Override public void handle(ActionEvent event) {
                loadView(new Locale("kg", "KG"));
            }
        });

        VBox root = new VBox(20);
        root.getChildren().add(HBoxBuilder.create().spacing(10).style("-fx-background-color: gray").padding(new Insets(5)).children(btnEN, btnKG).build());
        root.getChildren().add(new StackPane());
        primaryStage.setScene(new Scene(root, 300, 250));
        primaryStage.show();
    }

    private void loadView(Locale locale) {
        try {
            FXMLLoader fxmlLoader = new FXMLLoader();
            fxmlLoader.setResources(ResourceBundle.getBundle("bundles.MyBundle", locale));
            Pane pane = (BorderPane) fxmlLoader.load(this.getClass().getResource("MyView.fxml").openStream());
            // replace the content
            StackPane content = (StackPane) ((VBox) stage.getScene().getRoot()).getChildren().get(1);
            content.getChildren().clear();
            content.getChildren().add(pane);
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }

    public static void main(String[] args) {
        launch(args);
    }
}

Screenshot: