It's an interesting idea. We don't currently have a way to do this
directly. If you know the name and scope of the symbol being created on
the page, you could look for it in the symbol map for that page by
requesting the DTFacesContext, then going to the DTExternalContext.
I suppose a logical extension of this idea might be to have a cache of
IJavaTypeDescriptor's. We'd have to do it per-classpath (project), but it
might speed up a log of the property resolutions.