I'm accessing a server that doesn't send the content length for the HTTP request.
On the iPhone, .ondatastream() is called only twice: once with 0, once with 1. Since the content length is unknown I don't expect a progress bar, but it would be nice if this function were called more often so that I can at least update the user interface with the amount downloaded.
On Android, it's called every 1k block, and .progress returns an increasingly large negative number. I see there's a totalSize attribute to the event which is not mentioned in the docs or KitchenSink. With that I can update the interface to show how much has been downloaded, which is just fine. Arguably the .progress field should return 0 until the download has completely, however.