I personally would like to see it support null, not because null is a valid UI state but just to be consistent with all the other widgets. As far as pectin is concerned the bindings always created before the real value arrives so wigets are aften set to null. I've tried to avoid wiget specific logic in the core bindings as much as possible (it's a slippery slope to ugliness) and CheckBox is the odd one out. As a somewhat silly thought would a marker interface be an option i.e. perhaps something like `CheckBox implements HasValue, BarfsOnNull` so there's at least a mechanism to find out?
On Aug 26, 6:00 pm, Johan Rydberg <johan.rydb...@edgeware.tv> wrote: > On 8/25/10 6:16 PM, Ray Ryan wrote:> The use case is dealing with boolean > values that may benull, and > > really a check box is just the wrong UI there. Withdrawn. > > I know of at least one data binding framework, gwt-pectin, that signals > "no value" usingnull. As a work-around gwt-pectin has it's ownCheckBox > impl that acceptsnull. > > Take this example; We have a master-detail interface. aCheckBoxhas > been bound to "selectedElement.male". If there is not a selected > element, a "no value" signal should be sent down through data binding, > not "False". Right? > > But then again, there's really no way to communicate something like a > placeholder value for acheckbox. But I still thinkCheckBoxshouldacceptnull, > for the interface to be consistent. -- http://groups.google.com/group/Google-Web-Toolkit-Contributors
