ComboBox validation ( setRequired ) not working in customized form

Hi All,

I have form with customized form field factory, one of the elements is a ComboBox.
In this form, the combobox input is mandatory. so i used the setRequired(true);

The following is the code snippet for the combo box creation.

class BasicFormFieldFactory extends DefaultFieldFactory {

    String PROPERTY_CAPTION_NAME = "name";

    public Field createField(Item item, Object propertyId, Component uiContext) {
        if (propertyId.equals("data2")) {

            ComboBox cbox = new ComboBox();
            cbox.setRequiredError("Select a value.");
            return cbox;
        TextField tf = new TextField();
        tf.setCaption((String) propertyId);
        return tf;

    private Container getContainer() {

        IndexedContainer container = new IndexedContainer();
        container.addContainerProperty(PROPERTY_CAPTION_NAME, String.class, null);

        for (int i = 0; i < 10; i++) {
            Item systemItem = container.addItem("i" + i);
            systemItem.getItemProperty(PROPERTY_CAPTION_NAME).setValue("Data " + i);
        return container;

the form is set to immediate, as well as the combobox.
but still the form is getting submitted without any inputs from combobox.

Not sure what is wrong in my approach.
Attaching a test case for the same. The user is able to submit the form without selecting a value from the combobox, which should not be happening.

Thanks n Regardz
Vasu Patnaik. (1.66 KB)

I guess this is because the ComboBox is initially rendered without a selection, if no selection is made explicitly on the server side, even when the ComboBox has

I would consider this a severe bug, since traditional native select components always render the select with a default selection, usually the first item in the list.

Hi Jouni Koivuviita,

Thanks for the reply.
I have raised a ticket regarding this at this location - >

Thanks n Regardz
Vasu Patnaik.

The issue is not the combobox or the null value but that addField is overriden and fails to call registerField to register the property to the form. As there are no properties registered, validation will not validate anything. You probably meant to override attachField (used to add the field to the layout) instead of addField.

I have a big problem with validation in combobox. It is created by FieldFactory. And validation doesn’t work for this field.
It’s a little strange because the validation works when if you set something and return empty value back. But in initial state not working.

If I understood the property will validate If It was registered.


    public boolean addItemProperty(Object id, Property property) {

        // Checks inputs
        if (id == null || property == null) {
            throw new NullPointerException("Id and property must be non-null");

        // Checks that the property id is not reserved
        if (propertyIds.contains(id)) {
            return false;

        ownProperties.put(id, property);

        // Gets suitable field
        final Field field = fieldFactory.createField(this, id, this);
        if (field == null) {
            return false;

        // Configures the field

        // Register and attach the created field
        addField(id, field);

        return true;

public void addField(Object propertyId, Field field) {
        registerField(propertyId, field);
        attachField(propertyId, field);

Source code shows that combobox field will be registered anyway.
Where do I have mistakes?