XSchema question

Don Park donpark at quake.net
Wed Aug 5 11:46:56 BST 1998


>Hey!  Nice idea!  XSchema certainly supports this -- it's just a bunch of
XML


Thanks.  Support is, I suppose, unintentional?;-)

>Some comments:
>1) You've probably already realized this, but a DTD for such a file would
be of
>little or no use.  Because each XSchema section can introduce new elements
and
>redefine old ones, the DTD would probably consist of a bunch of elements
with
>content models of ANY.  This is of no use either for validation or
determining
>storage structures on the fly.


You are right but it makes perfect sense for transitory documents which
exists only while it is moving from one place to another.  Ability to
redefine default attribute values should be enough of a benefit I think.

>2) The above document is not well-formed.  You need to wrap it in a
container
>element such as <log-stream>.


Well, due to possible problems with missing root element's end tag (it ain't
there if the log file is not closed), XLF data is parsed as a well-formed
external entity like below.

<!DOCTYPE xlf [
<!ENTITY logfile SYSTEM "iis-08031998.xlf">
]>
<xlf>
&logfile;
</xlf>

>3) The semantics of how each successive XSchema affects the previous
XSchema are
>not well-defined (additive? total replacement? partial replacement?) and
>probably won't be defined in XSchema 1.0.   You are therefore on your own.
For
>safety's sake, I suggest you treat each XSchema as a completely new
definition
>of the following elements.


Food for thought.

Don



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