[xsl] Eliminating duplicates while processing: the answer...

[José Carlos Ramalho <jcr@xxxxxxxxxxxx>]

Hi, all. Tahnk you to those who reply to my question that was:

>I want to process a list of nodes that can appear at several different
>points of the structure, and I ant to process them in a particular order.
>This is easy to specify:
>
>         for-each select="//node-name"
>             sort select="criteria"
>
>The problem is that I want to supress the node's processing if it is equal
>to the one that precedes it in that order. How can I have access to the
last
>processed node while processing the current one?
>
>TIA
>jcr


I just found a nice solution in Bob DuCharme's column at O'Reilly:
        you just need to put the following test:
            <xsl:if test="not(.=preceding::node-name)"> ...

This way you can guarantee that if you have already processed a node with
the same content of current one you skip this one.

This helped me to solve an interesting problem: I had a Bibliography XML
file regarding to a DocBook application. Each BIBLIOENTRY has a list of
authors and I wanted to transform that structure into another that for each
AUTHOR lists his entries. This is a structure inversion problem is not
trivial in a normal programming language. Spite all the tags the XSL
solution is quite nice:

<xsl:template match="/">

<UL>

<xsl:for-each select="//AUTHOR">

<xsl:sort select="SURNAME" order="ascending"/>


<xsl:if test="not(./SURNAME=preceding::SURNAME)">

<xsl:call-template name="getEntries">

<xsl:with-param name="snome" select="SURNAME"/>

</xsl:call-template>

</xsl:if>

</xsl:for-each>

</UL>

</xsl:template>



Let´s come up with some new tags...

jcr

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José Carlos Ramalho                                   orienteer
Dep. Informática - U.Minho                          windsurfer
http://www.di.uminho.pt/~jcr                         engineer
+351 253 604479
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