getWebServiceObjectE doesn't notify if an error occured

[exelian]

If the request somehow failed, (eg. error 404, 500, server offline) there's no way of knowing except by leaking the implementation. Perhaps give the EventStream return by getWebServiceObjectE a new property which contains an EventStream that propagates any errors that might have occured.

Another solution would be to always return the XHR object, whether the request failed or not. That way a developer can check for any errors.