Mapping WebIntents to Network Service Discovery API

I'm attempting to map the existing Network Service Discovery API
(previously introduced to the DAP WG) to a WebIntents model. The existing
API is here:

http://people.opera.com/richt/release/specs/discovery/Overview.html

This API is very simple (one method) and only implements discovery.
Communication with discovered devices is out of scope. In prototypes, we
have implemented communication with XHR (with cross-origin restrictions
relaxed for white-listed devices).

I think the mapping is fairly straightforward with one exception. For some
protocols (e.g. UPnP) it is necessary to support device-initiated events.

Since I think this same requirement would exist for other frequently used
WebIntents examples (like printing documents), I think there must be a
common solution, but I'm having trouble finding one.

Here's a scenario that has probably already been explored that illustrates
my question:

1) The client wishes to print a document.
2) The client requests a "print" WebIntent with the document as the data.
3) A handful of printers that can handle the "print" WebIntent respond.
4) The client selects a printer to handle the print request.
5) Printing begins.
6) The printer runs out of paper before the document is completely
finished.
7) The client is notified that the printer is out of paper *** This is the
step I don't understand how to do with WebIntents ***
8) The user adds paper to the printer.
9) The print job is completed.

If someone could explain how WebIntents would implement this scenario
(especially step 7), that would be extremely helpful. If there are
existing documented examples you can reference that would be even better.

Thanks,
-Clarke

Received on Friday, 6 January 2012 23:38:07 UTC