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
IBindingListener listener = (IBindingListener) bindingEventIter
					.next();
			result = listener.bindingEvent(event);
			if (result != null)
				break;
		}
		return result;
	}
	/**
	 * Returns an observable list with elements of type Binding, ordered by
	 * creation time
	 * 
	 * @return the observable list containing all bindings
	 */
	public IObservableList getBindings() {
		return bindings;
	}
	/**
	 * Returns an observable value of type ValidationError, containing the most
	 * recent partial validation error
	 * 
	 * @return the validation error observable
	 */
	public IObservableValue getPartialValidationError() {
		return partialValidationError;
	}
	/**
	 * Returns an observable value of type ValidationError, containing the most
	 * recent full validation error, i.e. the last element of the list returned
	 * by getValidationErrors().