- From: Andrew Layman <andrewl@microsoft.com>
- Date: Thu, 22 May 1997 14:25:32 -0700
- To: "'w3c-sgml-wg@w3.org'" <w3c-sgml-wg@w3.org>
I have not been following the discussion on XML-LINK carefully, but there is one aspect of namespaces that I believe will affect links. That is, the names of elements must not be ambiguous. What I have in mind is that some namespace proposals have suggested that namespace qualifiers would be used or required only when two simultaneously active namespaces had the same name. That is, only if there is an actual conflict would you use a qualifier. That is too loose. If somebody built a path to an element based on a non-qualified name, but the name were later qualified in the target document, then the path could be broken. Similarly if something were originally qualified then became non-qualified. Etc. There needs to be a simple rule for when qualification is required, it must be as compatible as possible with existing documents, and it must be independent of the presence or absence of other namespaces. I suggest the following rule: Every element comes from some namespace. That becomes the default namespace for all sub-elements, attributes, etc. within. This namespace, and only this namespace, can be used without qualification. All others require qualification. To illustrate: > <CAR> > <SEATS>6</SEATS> > <ENGINE> > <CYLINDERS>6</CYLINDERS><DISPLACEMENT>4</DISPLACEMENT> > </ENGINE> > <a:COLOR>LIGHT CORAL<a:COLOR> > <b:DSIG><SUM>123456</SUM><WHO>Andrew</WHO></b:DSIG> > <BUYER> > <ssa:SSN>123456789</ssa:SSN> > <tei:XREF>http://ssa.gov</tei:XREF> > </BUYER> > </CAR> > > This has five namespaces running within CAR: The one from which CAR > comes, and also "a", "b", "ssa" and "tei". Presumably SEATS, ENGINE > and BUYER come from the same space as CAR. CYLINDERS and DISPLACEMENT > come from the same space as ENGINE. SUM and WHO come from the same > space as b:DSIG. > (I have omitted all reference to how the namespaces are imported, that being a different issue.) --Andrew Layman AndrewL@microsoft.com
Received on Thursday, 22 May 1997 17:25:38 UTC