Flash for quite some time now supports returning the HTTP status code for a URLRequest. I've added support for that to the LzHTTPLoader class for the SWF10 runtime: http://jira.openlaszlo.org/jira/browse/LPP-9894
By calling getResponseStatus() it's possible to retrieve the response status code of the last request for a dataset. Currently there is no public API to access the LzHTTPLoader instance, but the method can be reached through someDataset.dataRequest.loader.getResponseStatus(). How should that method/value be exposed on the dataset? Should we add an attribute "responsestatus"? DHTML supports response status values already, that means the functionality would be available for unproxied datasets across runtimes.
