RE: Removing duplicate elements a-priori?

[Gordon Vidaver <gvidaver@xxxxxxx>]

Mike,
        I'm trying to remove duplicate tags in the xml output.  That is, 
if the input xml file is :

        <doc>
          <A/>
          <A/>
        </doc>

        The output should be:

        <doc>
          <A/>
        </doc>

        Also, I don't want to have to know there is a tag named "doc" or 
"A" in the input document.  It would be fine if the output duplicates were 
only removed at the level of the children of the root.

        I tried this, and it doesn't produce any output:

  <xsl:key name="namekey" match="*" use="concat(generate-id(..), '/', 
name())"/>
  <xsl:template match="*">
    <xsl:apply-templates 
select="*[generate-id()=generate-id(key('namekey', concat(generate-id(..), 
'/', name ())))]"/>
  </xsl:template>

        I also tried

  <xsl:key name="namekey" match="doc/*" use="concat(generate-id(..), '/', 
name())"/>
  <xsl:template match="doc">
    <xsl:apply-templates 
select="*[generate-id()=generate-id(key('namekey', concat(generate-id(..), 
'/', name ())))]"/>
  </xsl:template>

        which also didn't work.

        Any help would be most appreciated...

        Thanks,

        Gordon

At 10:28 AM 6/19/00 +0100, you wrote:
> You haven't defined your requirement very clearly, but let's guess that your
> requirement is to copy the first instance of each child element type of the
> <doc> element.
>
> My first attempt was:
>
> <xsl:template match="doc">
> <xsl:apply-templates select="*[not(name(.)=name(preceding-sibling::*)]"/>
> </xsl:template>
>
> But of course this doesn't work, because name() applied to a node-set
> produces one name, not a set of names.
>
> So try the Muenchian solution using keys:
>
> <xsl:key name="namekey" match="doc/*" use="concat(generate-id(..), '/',
> name()"/>
>
> <xsl:template match="doc">
> <xsl:apply-templates select="*[generate-id()=
> generate-id(key('namekey', concat(generate-id(..), '/', name()))]"/>
> </xsl:template>
>
> Quicker to write than to explain. The key definition ensures that all <X>
> children of the same <doc> element have the same key value, for each element
> type X. The select expression includes every child of a <doc> element
> provided it is the same node (established by comparing the result of
> generate-id()) as the first entry in the list of nodes with that key value.
>
> Not tested.
>
> >
> >       For example I want to take :
> >
> >       <doc>
> >       <employee>Bill</employee>
> >       <employee>Andy</employee>
> >       <employee>John</employee>
> >       </doc>
> >
> >       And produce just :
> >
> >       <doc>
> >       <employee>Bill</employee>
> >       </doc>
> >
> >       without knowing that there is an employee tag in the input.
> >
> >       Any help would be most appreciated.
> >
> >       Thanks,
> >
> >       Gordon Vidaver
> >
> >
> >  XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list
> >
>
>
>  XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list


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