I would just like to revisit this question, because it will help clarify the "alternate" relation.
On 1 Mar 2005, at 11:39, Henry Story wrote:
On 20 Feb 2005, at 13:25, Bill de hÓra wrote:Graham, Eric,
My thinking goes like this,
- Is there a difference between an entry and the chunk of XML you see in a feed?
The question is vague and open to many interpretations, but I'd go for a yes.
- If there is, it will be in the same way there is a difference between a resource and a representation in web architecture.
Yes indeed that is the difference as I read it here [1].
I would like to be a little more specific now. If I take the following entry from the format 06 spec
<entry> <title>Atom-Powered Robots Run Amok</title> <link href="http://example.org/2003/12/13/atom03"/> <id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id> <updated>2003-12-13T18:30:02Z</updated> </entry>
Then we can say that the above Entry is a representation of the <urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a> resource.
Now my current reading of "alternate" is that this Entry representation
had an "alternate" representation at <http://example.org/2003/12/13/atom03>
at the time this entry representation was valid (2003-12-13T18:30:02Z)
Future representations of the <urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a>
resource may not have an "alternate" representation at that URL.
In which case perhaps the language of the "alternate" relation is a little
misleading
[[
The value "alternate" signifies that the IRI in the value of the href attribute identifies an alternate version of the resource described by the containing element.
]]
I think the above is much stronger than what a lot of people will agree to.
If I am reading correctly "the resource described by the containing element"
would be the <urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a> resource in the
example case.
So that our example xml would be saying that
<http://example.org/2003/12/13/atom03> is an alternate version of <urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a>, which is a lot stronger than what we want to say, since
we want to allow for domains being hijacked, dying, etc..
I think is much more precise to say that this representation
of <urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a> (the entry above) is an alternative representation of <http://example.org/2003/12/13/atom03> also.
Here we would be saying something that is true and helpful.
So perhaps the following would be better
[[
The value "alternate" signifies that the containing element is an alternative
representation of the IRI in the value of the href attribute.
]]
Henry Story
[1] http://www.w3.org/TR/webarch/#URI-persistence
