There was an error in the code I provided. When the original modelObject is
null and the checkbox is not checked, it should return true, and not false,
in order to consider the model has not changed. Comments are welcome !
if (currentValue == null && !Strings.isTrue(component.
>
> getConverter(compareValue.getClass()).convertToString(compareValue,
> component.getLocale()))){
> return *true*;
> }
Thanks,
Xavier
2010/3/5 Xavier López <[email protected]>
> Hi,
>
> I have a checkbox. The checkbox's Model is a PropertyModel, on a property
> that can be either a Boolean or a String, with values {S, N}. And I want to
> set the user and date in which the checkbox's model has changed, in order to
> provide traceability. The checkbox is using an implementation of IConverter
> when it's about Strings and the standard BooleanConverter otherwise.
>
> Now, the problem is, the value with which the checkbox is initialized *can*
> be null, if it has never been set. So, I can not rely on implementing
> 'onModelChanged()' because it will always fire the first time (in fact,
> having null value would be the same as having negative value as far as this
> requirement is concerned)
>
> I've tried different approaches, and I finally came up with the one that
> seems more logical to me, as it is close to a translation of what I've
> stated before. I'm overriding onModelChanged(), and implementing a custom
> IModelComparator, so that onModelChanged does not fire when changing value
> from null to 'nonselected'.
>
> Here follows the implementation. My question is, can't my custom comparison
> be implemented in a simpler way ? I can't get component.getInput(), because
> it's only a Component. And I'd not like to implement a util method to return
> a boolean from the ModelObject, doing instanceof's...
>
> Maybe I'm asking too much :-)
>
>
> public boolean compare(Component component, Object compareValue)
> {
> final Object currentValue = component.getModelObject();
> if (currentValue == null && compareValue == null) {
> return true;
> }
> if (currentValue == null || compareValue == null) {
> return false;
> }
>
> // MY CUSTOM COMPARISON: Null value equals not checking the
> checkbox
> if (currentValue == null &&
> !Strings.isTrue(component.getConverter(compareValue.getClass()).convertToString(compareValue,
> component.getLocale()))){
> return false;
> }
> else{
> return currentValue.equals(compareValue);
> }
> }
>
>
> Thanks ! feel free to comment :-)
>
