class AssignmentListItemWidgetViewImpl extends Composite implements AssignmentListItemWidgetView,
                                                                           ComboBoxView.ModelPresenter {

    @PostConstruct
    public void init() {
        name.setRegExp(ALLOWED_CHARS,
                       StunnerFormsClientFieldsConstants.CONSTANTS.Removed_invalid_characters_from_name(),
                       StunnerFormsClientFieldsConstants.CONSTANTS.Invalid_character_in_name());
        name.addChangeHandler(event -> {
            String value = name.getText();
            String notifyMessage = null;
            if (isMultipleInstanceVariable(value)) {
                notifyMessage = StunnerFormsClientFieldsConstants.CONSTANTS.AssignmentNameAlreadyInUseAsMultipleInstanceInputOutputVariable(value);
            } else if (!allowDuplicateNames && isDuplicateName(value)) {
                notifyMessage = duplicateNameErrorMessage;
            }
            if (notifyMessage != null) {
                notification.fire(new NotificationEvent(notifyMessage, NotificationEvent.NotificationType.ERROR));
                name.setValue(EMPTY_VALUE);
                ValueChangeEvent.fire(name, EMPTY_VALUE);
            }
        });
        customDataType.setRegExp(StringUtils.ALPHA_NUM_UNDERSCORE_DOT_REGEXP,
                                 StunnerFormsClientFieldsConstants.CONSTANTS.Removed_invalid_characters_from_name(),
                                 StunnerFormsClientFieldsConstants.CONSTANTS.Invalid_character_in_name());
        customDataType.addKeyDownHandler(event -> {
            int iChar = event.getNativeKeyCode();
            if (iChar == ' ') {
                event.preventDefault();
            }
        });
        dataTypeComboBox.init(this,
                              false,
                              dataType,
                              customDataType,
                              false,
                              true,
                              CUSTOM_PROMPT,
                              ENTER_TYPE_PROMPT);
        processVarComboBox.init(this,
                                false,
                                processVar,
                                expression,
                                true,
                                true,
                                EXPRESSION_PROMPT,
                                ENTER_EXPRESSION_PROMPT);
    }

}