GData and INVOKE

That HTTP header is optional. It's a fallback header for when firewalls/proxy servers between client and server prevent standard HTTP PUT AND HTTP DELETE from getting through.

Your commentary sounds like you expect them to add more actions. I very much doubt they will. They have all the actions they need. Create, Read, Update, Delete. They're all the verbs you need.

So you see, SoapAction is moving the meaning of the operation up a level into the protocol. The REST-style interaction of GData doesn't encode this sort of information into the protocol. It is presumed you know what you are manipulating given the endpoint you are accessing.

GData is about manipulating lists. So you add a new item to a list, update a number of items from a list, delete an item from a list and read and list. These are much more basic forms of data manipulation than SOAP tried to solve. But as the world re-learns the power of lists (LINQ anyone?), we're also relearning that data manipulation in a client-server scenario can be handled in the same way.

Rich,

I have no idea whether Google will or won't add more actions to their "sub-method" HTTP header.

I agree that if the current approach looks like a pure "tunnel HiREST through LoREST" which is a pragmatic nod to the fact that lots of the web only really supports LoREST.

DB

The "lots of the web" that only really supports LoREST seems to be HTML Forms. Firewalls that block PUT and DELETE do so for a reason, even if that reason may be stupidity. I'm not sure the Web wouldn't be better off without workarounds such as the GData one.

In any case, I believe there's a huge difference between their workaround and the SOAP approach - the GData folks started out RESTfully and added this workaround afterwards, not as part of the original architecture.

Stefan,

I agree the premises of SOAPACtion vs the GData workaround are different.

What I'm observing is that pragmatically, the GET/POST combo is the underlying reality and that multiple interpretations get layered above it.

To me, that point is huge, no matter which side of the "uniform interface vs. arbitrary invocation" argument you take.

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