Re: Expanded names are not enough

Simon St.Laurent (SimonStL@classic.msn.com)
Thu, 6 Aug 98 13:34:40 UT


James Clark writes:
>I suspect there will be a similar issue with XPointers. If I say:
>
> href="http://...#descendant(17,foo:bar)"
>
>I would expect that the expanded element type names to be matched, not
>the prefixes. That would mean that to interpret the XPointer, an
>application would need the namespace prefix to namespace URI mapping in
>effect for the element to which href attribute is attached.

This is actually my primary concern with the current namespace proposal: that
the inheritance model used here makes it difficult to extract subsections of
documents reliably. I would strongly prefer NOT to have the client need to
download the entire document containing the subsection referred to by the
XPointer - ideally, the server could just send the piece requested.
(Bandwidth still isn't free, you know.) This model opens up an awful lot of
possibilities, but I fear namespaces may snuff it out.

So to make a this kind of request involving a namespace, the client will need
to expand the prefix within the (foo:bar) which yields URLs like

http://...#descendant(17,http://www.simonstl.com/schema/v1:bar)

Maybe this will work, but it sure makes for a mess. Then the server needs to
keep a namespace-expanded version of the documents it's storing if it wants to
process this with any degree of speed, since parsing the whole document and
expanding namespaces gets to be a chore when you're answering lots of requests
simultaneously.

What I'd hoped to do with a simple Java servlet now looks like an _incredible_
mess. Maybe the XPointer folks have some better ideas...

Simon St.Laurent
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