[xsl] Prior Instance of term in main text, before first glossary markup

[David Riggs <dariggs@xxxxxxxxxxxxxx>]

Dear XSL listers,

I am marking up foreign words so that I can display the Japanese/Chinese
characters in my text, but only for only the first usage of a term, and
also to have the stylesheet generate a glossary at the end. Cutting and
pasting and rewriting, it is easy to forget if I have already "glossed" a
term or not, and I cannot figure out a correct xsl test to see if the term
is properly marked up the first time it is used. That is to say, I need to
test to see if the word has been used before (in document order) in the
source tree, before the first glossary markup.


It seems like it should be easy to check with a simple <xsl:if test---> but
I do not seem to be able to get it to work, and I do not see anything
relevant in the archives.

If I have this source, to make the smallest example:

<p>The Buddhist way is zazen. When first practicing sitting meditation
<mygloss><gr>zazen</gr><gk>==Japanese Characters==</gk></mygloss> select a
quiet place. </p>

And my stylesheet includes:

<xsl:template match="mygloss">
<xsl:if test="contains(ancestor::text(), gr) or contains(preceding::text(), gr)">
       XXX ERROR-- NOT FIRST USAGE XXX
     </xsl:if>
<!----- rest  of template to put in italic, proper font, check for first
gloss markup of this word etc -->
</xsl:template>

The above test does not find and output the error of the earlier first use,
i.e. when I forgot to gloss it when I first used in the beginning of the 
paragraph (or anywhere earlier, to make the general case).

I tried this test:

contains(ancestor::*, gr) or contains(preceding::*, gr)

But the test is always true, even if there is no prior use.

This following test works if the word is not further marked up in the
paragraph, but of course it fails to look in end notes and such:

contains(ancestor::p/text(), gr) or contains(preceding::p/text(), gr)

So, in sum, how do I do this properly? And of course, a kind explanation to
get me out of my confusion about the xpath and xsl would be very much 
appreciated.

David Riggs

International Research Center for Japanese Studies, Kyoto