Re: Handling unknown elements in an entry

[David Powell <djpowell@xxxxxxxxxxxx>]

>> HTTP works exactly this way. I can send If-None-Match
>> or If-Modified-Since and if the server doesn't support
>> them they are ignored. It seems you are suggesting
>> that HTTP servers are either supposed to (a) error or
>> (b) store these header values and return them even
>> though they do nothing with them. 

> No, I'm talking about the body of a PUT request. Are you discussing 
> metadata elements (e.g. atom:category) and HTTP headers interchangeably?
> If so, I get it.


Just for info — I'm not necessarily saying that Atom should behave
this way:

According to HTTP:  [1]

> Unless otherwise specified for a particular entity-header, the
> entity-headers in the PUT request SHOULD be applied to the resource
> created or modified by the PUT.

and [2]

> The extension-header mechanism allows additional entity-header
> fields to be defined without changing the protocol

  [in other words, all extension headers are implicitly
  entity headers]


So, for HTTP, PUT "SHOULD" preserve all headers including extension
headers.


The same is true of PROPPATCH in WebDAV: [3]

> DAV compliant resources SHOULD support the setting of arbitrary dead
> properties.


I think WebDAV can communicate which properties weren't set via the
207 response though? Perhaps Atom protocol could do with a feature
like this?


[1] http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9.6
[2] http://www.w3.org/Protocols/rfc2616/rfc2616-sec7.html#sec7.1
[3] http://www.webdav.org/specs/rfc2518.html#METHOD_PROPPATCH

-- 
Dave