On 5 Feb 2005, at 18:27, David Powell wrote:
I disagree, as I've said before. The only literal interpretation is that you can't serve the same entry twice with the same id. We know it doesn't mean that, but the spec just doesn't define in which axis "unique" is meant to apply.
I think that the problem is that the term 'entry' is used to refer to two different concepts.
An entry id is identifying the underlying entry resource.
But something like an entry title, I would think of as a property of the 'entry instance'.
Currently we don't distinguish between entries and entry instances, and I think that this creates a lot of ambiguity.
I agree with this analysis. But I think one can deal with it. A simple OWL ontology would make these things very clear.
Although we could keep the model we have (let's call it
the 'mutable entries' model), it isn’t clear on a number of issues. Eg, if an old version of an entry has some property that isn’t present in a newer version, does that property still apply to the new instance? The answer is presumably 'no' but it isn't obvious from the spec. Under a 'multiple instances' model, it would be implicit.
It is easiest if one starts off deciding that no properties get inherited. Some properties do seem to clearly require inheritance such as the author, as one would expect all the versions of an entry to have the same author. But the amount of debating that this would require would not be worth the effort. The id property does the job very nicely and inconspicuously.
At one point I had thought that properties such as author should be directly attached to the id construct, since they are immutable. But then one gets into problems of which are essential and which non essential properties...
Henry Story
-- Dave
