JavaFX Input Validation Textfield

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I'm using JavaFX and Scene Builder and I have a form with textfields. Three of these textfields are parsed from strings to doubles.

I want them to be school marks so they should only be allowed to be between 1.0 and 6.0. The user should not be allowed to write something like "2.34.4" but something like "5.5" or "2.9" would be ok.

Validation for the parsed fields:

public void validate(KeyEvent event) {
    String content = event.getCharacter();
    if ("123456.".contains(content)) {
            // No numbers smaller than 1.0 or bigger than 6.0 - How?
    } else {
        event.consume();
    }
}

How can I test if the user inputs a correct value?

I already searched on Stackoverflow and on Google but I didn't find a satisfying solution.

textField.focusedProperty().addListener((arg0, oldValue, newValue) -> {
        if (!newValue) { //when focus lost
            if(!textField.getText().matches("[1-5]\\.[0-9]|6\\.0")){
                //when it not matches the pattern (1.0 - 6.0)
                //set the textField empty
                textField.setText("");
            }
        }

    });

you could also change the pattern to [1-5](\.[0-9]){0,1}|6(.0){0,1} then 1,2,3,4,5,6would also be ok (not only 1.0,2.0,...)

update Here is a small test application with the values 1(.00) to 6(.00) allowed:

public class JavaFxSample extends Application {

@Override
public void start(Stage primaryStage) {
    primaryStage.setTitle("Enter number and hit the button");
    GridPane grid = new GridPane();
    grid.setAlignment(Pos.CENTER);
    Label label1To6 = new Label("1.0-6.0:");
    grid.add(label1To6, 0, 1);
    TextField textField1To6 = new TextField();

    textField1To6.focusedProperty().addListener((arg0, oldValue, newValue) -> {
        if (!newValue) { // when focus lost
                if (!textField1To6.getText().matches("[1-5](\\.[0-9]{1,2}){0,1}|6(\\.0{1,2}){0,1}")) {
                    // when it not matches the pattern (1.0 - 6.0)
                    // set the textField empty
                    textField1To6.setText("");
                }
            }
        });
    grid.add(textField1To6, 1, 1);
    grid.add(new Button("Hit me!"), 2, 1);
    Scene scene = new Scene(grid, 300, 275);
    primaryStage.setScene(scene);
    primaryStage.show();
}

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

}

JavaFX TextField text validation, If you want to do input validation when the text is changing, you could use a listener on the textProperty of the TextField : textField.textProperty(). SIMPLE JAVAFX TEXTFIELD INPUT VALIDATION SIMPLE JAVAFX TEXTFIELD INPUT VALIDATION "ON KEY RELEASED" In this example we will validate the user name with the following

I would not advise you to use KeyEvent for that.

You should use a more classical way such as validated the user input when the user finish to fill the text field or click on a save button.

/**
 * Called this when the user clicks on the save button or finish to fill the text field.
 */
private void handleSave() {
        // If the inputs are valid we save the data
        if(isInputValid()){
            note=(DOUBLE.parseDouble(textField.getText()));
        }else // do something such as notify the user and empty the field
}

/**
 * Validates the user input in the text fields.
 * 
 * @return true if the input is valid
 */
private boolean isInputValid() {
    Boolean b= false;
    if (!(textField.getText() == null || textFiled.getText().length() == 0)) {
        try {
            // Do all the validation you need here such as
            Double d = Double.parseInt(textFiled.getText());
            if ( 1.0<d<6.0){
                b=true;
            }
        } catch (NumberFormatException e) { 
        }
    return b;
}

JavaFx JFoenix Tutorial #3 : JFXTextField With Input Validation , A "Validator" can be associated with these TextFields so as to check whether the given input Duration: 13:41 Posted: Jun 9, 2016 Introduction to JavaFX TextField. In the JavaFX package, a class known as TextField helps the users to enter the unformatted text that can be read by the application. The text should not be of multiple lines as it allows only a single line of the input text. This JavaFX TextField control can be instantiated from the class javafx.scene.control

In case you can use a third party library:

Similar question has been aswered here: Form validator message .

For your case, you would choose a RegexValidator to check the textfield input, and pass the regex that you arrived to from previous answers:

    JFXTextField validationField = new JFXTextField();
    validationField.setPromptText("decimal between 1.0 and 6.0");
    RegexValidator validator = new RegexValidator();
    validator.setRegexPattern("[1-5](\\.[0-9]{1,2}){0,1}|6(\\.0{1,2}){0,1}");
    validator.setMessage("Please enter proper value");
    validationField.getValidators().add(validator);
    validationField.focusedProperty().addListener((observable, oldValue, newValue) -> {
        if(!newValue)
                validationField.validate();
    });

SIMPLE JAVAFX TEXTFIELD INPUT VALIDATION, SIMPLE JAVAFX TEXTFIELD INPUT. VALIDATION. "ON KEY RELEASED". In this example we will validate the user name with the following� JavaFX Input Validation Textfield. Tag: java,javafx. I'm using JavaFX and Scene Builder and I have a form with textfields. Three of these textfields are parsed from

You can prevent illegal input using TextFormatter:

final Pattern pattern = Pattern.compile("(6\\.0)|([1-5]\\.[0-9])");
textField.setTextFormatter(new TextFormatter<>(new DoubleStringConverter(), 0.0, change -> {
        final Matcher matcher = pattern.matcher(change.getControlNewText());
        return (matcher.matches() || matcher.hitEnd()) ? change : null;
}));

Using JavaFX UI Controls: Text Field, This chapter discusses the capabilities of the text field control. The TextField class implements a UI control that accepts and displays text input. It provides� Text input component that allows a user to enter a single line of unformatted text. Unlike in previous releases of JavaFX, support for multi-line input is not available as part of the TextField control, however this is the sole-purpose of the TextArea control.

Validation in java (javafx), Validation is one thing that's missing from the core javafx framework. snippet I define a textfield and password field for entering the login details. This validators, check whether the input in question is empty and if so they� The TextField class implements a UI control that accepts and displays text input. It provides capabilities to receive text input from a user. Along with another text input control, PasswordField, this class extends the TextInput class, a super class for all the text controls available through the JavaFX API.

JavaFX Email Validation using JFoenix TextField, So here's full example of how to validate email in JavaFX text field. import com. jfoenix.controls.JFXButton; import com.jfoenix.controls.JFXTextField; import� TextField class is a part of JavaFX package. It is a component that allows the user to enter a line of unformatted text, it does not allow multi-line input it only allows the user to enter a single line of text. The text can then be used as per requirement. Constructor of the TextField class: TextField(): creates a new TextField with empty text

Validation in JavaFX, Validation is one thing that's missing from the core javafx framework. I define a textfield and password field for entering the login details. All you have to do is validate the input string against the desired string pattern. In this case, the pattern seems to be one or more digits, followed by a period, AND exactly 4 digits after the decimal point.

Comments
  • Thank you very much @griFlo but there is still an issue. I can't enter a value like "5.0", "4.7", "2.8" or "1.9". And do you know how I can tell the program that there should only be two decimal places?
  • @BRsmover all the values you said, should be allowed (in fact, i just tested it with the above code and it works just find). What do you mean by two decimal places? you could use this regex for that [1-5](\.[0-9]{1,2}){0,1}|6(.0{1,2}){0,1} (if I understood you correctly)
  • I'm sorry I must have misunderstood something... Everything works perfectly fine! Thank you very much!
  • I would elaborate on this. I would call the validation method 3 times: on the save action, on the action event of the text field and on losing the focus. This way the user gets an immediate response in case of error, in addition to preventing the saving of bad data.