Idempotent methods, HTTP PUT, and app:edited

[Nikunj Mehta <nikunj.mehta@xxxxxxxxxx>]

Has anyone pondered the idempotence of a PUT method on an APP member 
resource?

If you attempt to PUT repeatedly, then the first one that succeeds will 
set a new ETag expectation. Subsequently, if PUT requests with 
"if-match" preconditions are made, these would fail thus saving the 
idempotence requirement on PUT (RFC 2616, 9.1.2). OTOH, without 
preconditions, we have to store the new entity and change the app:edited 
element. IMHO, That creates a "side-effect", and hence is not an 
idempotent operation.

Nikunj