Showcase Start Screen "Data Binding" CheckboxItem validation issue

Smart GWT Technical Q&A
1

Hello,

I discovered a problem with CheckboxItem validation in version 2.4.
When you tick then untick and afterwards validate, the checkbox still tells true.
For proof I tried the showcase here: http://www.smartclient.com/smartgwt/showcase/#layout_form_databinding and its the same happening no matter if using IE or Firefox. Please help. Thanks.

SmartGWT 2.4, Firefox or IE does not matter

2

What is actually happening is that the field (accept checkbox) is set to required which means the user must place a value there. Once the user checks the box (or unchecks it) the field has a value. It may be true or false but it still has a value and thus passes validation. A “required” checkbox does not mean that the box must be checked to be valid. You must use a different validator to enforce that rule.

This sample should be updated with a validator that requires the box to be checked to meet the expected result.

3

Hi david,

thanks for your hint!!
Even though its not logic - my opinion - here is the solution if you need a checkbox being ticked in terms of required:

DynamicForm form = new DynamicForm();
CheckboxItem check = new CheckboxItem();
check.setRequired(true);
check.setValidators(new CustomValidator() {

@Override
protected boolean condition(Object value) {
return (Boolean) (value == null ? false : value);
}
});
form.setFields(check);

Then just call when the form is submitted:
form.validate(false);

Cheers
~limubai

4

Here is another solution.

CheckboxItem checkboxItem = new CheckboxItem();

checkboxItem.addChangeHandler(new ChangeHandler() {
public void onChange(ChangeEvent event) {

			if (checkboxItem.getValueAsBoolean()) 
                                checkboxItem.clearValue();
				}

}