Bug 140644 [DataBinding] Binding to ValidationError of DataBindingContext is broken
Hello, I wanted to bind the ValidationError Observable to a Widget, and it doesn't seem to work. I tested with Jface Databinding sample and in TestMasterDetails.java example, instead of binding the simple date error to a label, I bound the ValidationError of DBC to the Label (with a simple converter). dbc.bind(validationError, dbc.getValidationError(), new BindSpec().setUpdateModel(false).setModelToTargetConverter(new IConverter() { public Object convert(Object fromObject) { // TODO Auto-generated method stub if (fromObject == null) return null; return ((ValidationError) fromObject).message; } public Object getFromType() { // TODO Auto-generated method stub return Object.class; } public Object getToType() { // TODO Auto-generated method stub return String.class; } })); After investigating, I saw the ValidationError is a computed value (very interesting concept and useful) on the ValidationErrorList. 1. The ComputedValue mechanism seems to use the StateListener to the Object, but I don't see any management of staleness in ValidationErrorList (or ObservableList). 2. When one of the field gets an error, I debug and saw the ChangedListener on my binding was null (whereas the ValidationErrorList registers listeners on them). At the beginning, it's registered, the removed and not added again when needed. I have not enough time to go deeper in the mechanism, could you help me to understand what I'm doing wrong with this simple binding (With previous releases I was already binding with that mechanism and it worked). Is there an other way to do this? (My workaround is a listener on DBC, but I would prefer to use ValidationError Computed value). Thanks in advance
bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/databinding/DataBindingContext.java
if (bindSpec.getModelToTargetConverter() == null) {
				bindSpec.setModelToTargetConverter(dataBindingContext
						.createConverter(modelType, targetType));
			}
		}
		IConverter[] targetToModelConverters = bindSpec
				.getTargetToModelConverters();
		if (targetToModelConverters.length > 1) {
			for (int i = 0; i < targetToModelConverters.length; i++) {
				if (targetToModelConverters[i] == null) {
					targetToModelConverters[i] = dataBindingContext
							.createConverter(targetType, modelType);
				}
			}
		} else {
			
			
			
			if (bindSpec.getTargetToModelConverter() == null) {
				bindSpec.setTargetToModelConverter(dataBindingContext
						.createConverter(targetType, modelType));
			}
		}
	}
	protected ValidationError fireBindingEvent(BindingEvent event) {
		ValidationError result = null;
		for (Iterator bindingEventIter = bindingEventListeners.iterator(); bindingEventIter
				.hasNext();) {