Mark Baker wrote:
I don't quite follow, but idempotence just means that the effect of N
messages is the same as 1.
Exactly the point. When you see N different PUT requests, each produces
a different app:edited (and hence a different ETag) value in the member
entity. Doesn't that make this behavior *not* idempotent?
Yes and no.
If your tag is for instance a hash value of the resource, it will be
indeed different each time app:edited is amended. But your Etag could for
instance be a hash of a combination of both the atom:id and atom:updated.
This value will then change only when a significant modification happened
to the resource.