JavaFX is a great toolkit for quickly building UIs that look and feel good. But if you have implemente UIs with JSF or JQuery etc, you might be used to a simple way of defining validation rules on UI input elements. fx-validation is an extension to fx-actions that lets you do just that: declaratively define validation rules on UI controls.
At present, fx-validation supports these validation rules:
- @FXRequired
- @FXNumber(min=?, max=?)
- @FXString(minLength=?, maxLength=?)
- @FXNotNull
- @FXValidation // for custom validator classes
The validation rules are applied to the fields in the controller. A sample controller might look like this one from the aeFXValidationTest demo application:
/**
* An example controller that illustrates the use of the aeFXValidation
* framework.
*
* @author Robert Rohm <r.rohm@aeonium-systems.de>
*/
public class FXMLDocumentController implements Initializable {
/**
* This textfield requires any input. It is provided a custom message.
*/
@FXML
@FXRequired(required = true, message = "bitte eingeben!")
private TextField tf1;
/**
* If you need internationalized messages, provide a resource bundle to the
* ValidatorService: This annotation uses a key from the resource bundle as
* message text.
*/
@FXML
@FXRequired(message = "validation.messages.required")
private TextField tf2;
/**
* This textfield uses string validation with a minimum and a maximum length.
*/
@FXML
@FXString(minLength = 2, maxLength = 5)
private TextField tf3;
/**
* This textfield is validated against a regular expresion and uses the
* <code>messagePattern</code> attribute.
*/
@FXML
@FXString(pattern = "[a-z]*", messagePattern = "Lowercase only ;-)")
private TextField tf14;
/**
* This textfield requires input that can be parsed as a integer or float
* value. The range of <code>double</code> is supported.
*/
@FXML
@FXNumber
private TextField tf4;
/**
* This textfield requires the input to be a number within a given range. You
* may specify minima and maxima also as double values.
*/
@FXML
@FXNumber(min = 5, max = 15)
private TextField tf6;
/**
* The visibility of this textfield can be toggled, so it is only validated
* conditionally when it is visible.
*/
@FXML
@FXString(minLength = 2, maxLength = 5)
private TextField tfVisible2;
@FXML
private Label label;
@FXML
private CheckBox cbEnableTf5;
@FXML
private CheckBox cbToggleVisibilityTf2;
/**
* Example: Message ID from the resource bundle gets picked up if present.
*/
@FXML
@FXRequired(message = "validation.messages.required")
private TextField tf5;
/**
* "NotNull" Validation for ChoiceBoxes is supported.
*/
@FXML
@FXNotNull
private ChoiceBox chb1;
/**
* "NotNull" Validation for ComboBoxes is supported.
*/
@FXML
@FXNotNull
private ComboBox cmb1;
/**
* "NotNull" Validation for DatePickers is supported.
*/
@FXML
@FXNotNull
private DatePicker dp1;
/**
* You can also apply custom validators to a control, and implement your own
* validation logic.
*/
@FXML
@FXValidation(validation = CustomValidator.class)
private TextField tfCustom;
/**
* This button is the "submit" button of the form - therefore it must be
* constrained to be enabled only when all validation constraints have been
* checked successfully.
*/
@FXML
@FXValidationChecked
private Button button;
/**
* Alternatively to binding a submit button directly to the validation
* results, you may bind a boolean property to them, that is used to bind
* several control's "disable" properties to.
*/
@FXValidationChecked
private BooleanProperty isOK = new SimpleBooleanProperty(false);
This example show the loading and initialization of a FXML UI with internationalization. If you need I18N support, you might provide separate property bundles, one for the FXML UI and one for the validation messages.
@Override
public void start(Stage stage) throws Exception {
// Get the pre-configured controller factory:
FXActionManager myActionControllerFactory = ValidatorService.createActionManager();
// Load the FXMl with the controller factory
FXMLLoader fxmlLoader = new FXMLLoader();
fxmlLoader.setLocation(getClass().getResource("FXMLDocument.fxml"));
fxmlLoader.setResources(ResourceBundle.getBundle("com.aeonium.aefxvalidationtest.text"));
fxmlLoader.setControllerFactory(myActionControllerFactory);
Parent root = (Parent) fxmlLoader.load();
Scene scene = new Scene(root);
// Add the validation stylesheet - if you have not done so in the FXML
scene.getStylesheets().add("/com/aeonium/javafx/validation/aeFXValidation.css");
// Load and set the resource bundle
ValidatorService.setBundle(ResourceBundle.getBundle("com.aeonium.aefxvalidationtest.messages"));
// Register all Label instances with the LabelService
LabelService.initialize(scene);
myActionControllerFactory.initActions();
ValidatorService.initialize(fxmlLoader.getController());
stage.setTitle("fx-validation I18N Test");
stage.setScene(scene);
stage.show();
}