AFAIK, it is not possible to create or use a Reference to a ResourceCollection, because the id/refid attributes aren't present in the respective implementation classes. This is a serious constraint, because (for example) there is no possibility to pass resource collections to a macro.
Not sure I follow you here. It is true the ResourceCollection interface doesn't support refif/id directly but (almost?) all concrete implementations of the interface do. What exactly are your trying to do that isn't possible? I'm not completely sure we have documented it, but I think we do. The <resources> type is the generic collection if you need a placeholder for any type of resource collection. It's getRef() method casts the ref to ResourceCollection and not to any concrete subclass. http://ant.apache.org/manual/Types/resources.html#resources
nearly 1yr after Stefans feedback. Is the problem solved?