On 7 Feb 2005, at 13:33, Roy T. Fielding wrote:
If it is reasonable to say that, at any single point in time, only one representation of a given entry can appear in the feed's representation, then the only valid representation of a feed is one that does not contain any duplicate entry id's.
This is true only if you have the [Equivalence ID] interpretation of the id relation. (Ie you think of id as equivId.)
Yes, and to make myself perfectly clear, that means functional ID, as you call it, would conflict with the design of Atom and any reasonable design of a system wherein the things being identified are allowed to be updated over time.
I wonder if you read the rest of my message...
I gave an example that did not conflict with a reasonable design.
Here is a reasonable design of the files in a web site for an entry with versioning:
entry03 <-- a directory resource pointed to by the funcId uri entry03/v1 <-- a directory resource for the previous entry version entry03/v1/entry.xml <-- the first entry version of the xml entry03/v1/entry.html <-- the second entry version in html form entry03/v2 <-- a directory resource pointed to by the equivId uri entry03/v2/entry.xml <-- the second entry version in xml format entry03/v2/entry.html <-- the first entry version in html format
Here is a reasonable feed corresponding to the above file system layout of resources:
<feed>
<entry>
<title>Atom-Powered Robots Run Amok!</title>
<link href="http://bblfish.net/2005/02/07/entry03/v1/entry.html"/>
<funcId>http://bblfish.net/2005/02/07/entry03/</id>
<equivId>http://bblfish.net/2005/02/07/entry03/v1/</id>
<updated>2003-12-13T18:30:02Z</updated>
</entry>
<entry>
<title>Atom-Powered Robots Run Amok</title>
<link href="http://bblfish.net/2005/02/07/entry03/v2/entry.html"/>
<funcId>http://bblfish.net/2005/02/07/entry03/</id>
<equivId>http://bblfish.net/2005/02/07/entry03/v2/</id>
<updated>2003-12-13T18:30:02Z</updated>
</entry>
</feed>((It seems to me that when blogging it is very good practice to keep the changes of one's entries available as above, since one's changing one's mind on an issue affects the pages and comments of other people pointing to your entry.))
Anyway, as you see I am agreeing with you that equivId will be different for each entry in a feed, though funcId is the same. There we have a feed that contains both notions.
So, please, stop trying to make a real system fit an artificial model of graph theory that isn't even capable of describing the Web. Fix your model instead.
Do you have a good paper that proves your incredibly strong statement
above? I would be happy to understand this position, as it would save
me a lot of time. But I can't just take your word for it, as there
are numerous people who don't seem to think the way you do, and in
just as senior or more senior positions than your are. But perhaps
I have missed some important development recently. (I am not being ironic here though it may sound like it. I really would like to
understand more fully your position.)
Henry Story
