RE: [xsl] Template removes non-duplicate elements

["Michael Kay" <mike@xxxxxxxxxxxx>]

You need to explain the rules. If you consider the two "Porta Coeli" entries
to be distinct, you need to say why.

Perhaps you only want to eliminate duplicates if they have an Xref/Heading
element? In that case, change

<xsl:copy-of select="current-group()[1]"/>

to

<xsl:copy-of select="current-group()[if (Xref/Heading) then 1 else
true()]"/>

(I think that's the first time I have ever encountered a genuine use case
for a predicate that can be either numeric or boolean...)

Michael Kay
http://www.saxonica.com/ 

> -----Original Message-----
> From: Mark Wilson [mailto:mark@xxxxxxxxxxxx] 
> Sent: 14 March 2009 01:42
> To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> Subject: [xsl] Template removes non-duplicate elements
> 
> My attempt at duplicate removal is failing in that it removes 
> more than I want it to. Listing 2 is the input file. The 
> output file should have one of the two duplicate initial 
> <item>s removed (Listing 1), everything else should stay. My 
> broken template is in Listing 3. It removes one of the 
> duplicates and two of the three non-duplicate  <Item> s. (see 
> Listing 4).
> 
> Can someone help me fix my template?
> Thanks,
> Mark
> 
> Listing 1.
> <Item>
>         <Heading entry="subject">Monasteries</Heading>
>         <Xref xref="see">
>             <Heading entry="subject">Abbeys and Monasteries</Heading>
>         </Xref>
>     </Item>
> 
> Listing 2.
> 
> <List>
> <Item>
>         <Heading entry="subject">Monasteries</Heading>
>         <Xref xref="see">
>             <Heading entry="subject">Abbeys and Monasteries</Heading>
>         </Xref>
>     </Item>
>     <Item>
>         <Heading entry="subject">Monasteries</Heading>
>         <Xref xref="see">
>             <Heading entry="subject">Abbeys and Monasteries</Heading>
>         </Xref>
>     </Item>
>     <Item>
>         <Heading entry="subject">Abbeys and Monasteries</Heading>
>         <Level1>
>             <SubDiv1>St Nicholas. Postal Card</SubDiv1>
>         </Level1>
>     </Item>
>     <Item>
>         <Heading entry="subject">Abbeys and Monasteries</Heading>
>         <Level1>
>             <SubDiv1>Porta Coeli</SubDiv1>
>             </Level1>
>     </Item>
>     <Item>
>         <Heading entry="subject">Abbeys and Monasteries</Heading>
>         <Level1>
>             <SubDiv1>Porta Coeli</SubDiv1>
>         </Level1>
>     </Item>
>     <Item>
>         <Heading entry="subject">Abbeys and Monasteries</Heading>
>         <Level1>
>             <SubDiv1>Strahov</SubDiv1>
>             <Level2>
>                 <SubDiv2>Strahov Madonna</SubDiv2>
>                   </Level2>
>         </Level1>
>     </Item>
>     </List>
> 
> Listing 3.
> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"; 
> xmlns:xs="http://www.w3.org/2001/XMLSchema"; 
> exclude-result-prefixes="xs" 
> version="2.0">
>         <xsl:strip-space elements="*"/>
> 
> <xsl:template match="@* | node()">
>      <xsl:copy>
>        <xsl:apply-templates select="@* | node()"/>
>      </xsl:copy>
>    </xsl:template>
> 
>     <xsl:template match="/">
>         <List>
>             <xsl:for-each-group select="//Item" 
> group-by="concat(Heading, Xref/Heading)">
>                 <xsl:copy-of select="current-group()[1]" 
> copy-namespaces="no"/>
>             </xsl:for-each-group>
>         </List>
>     </xsl:template>
> 
> </xsl:stylesheet>
> 
> Listing 4.
> <List>
>     <Item>
>         <Heading entry="subject">Abbeys and Monasteries</Heading>
>         <Level1>
>             <SubDiv1>St Nicholas. Postal Card</SubDiv1>
>         </Level1>
>     </Item>
>     <Item>
>         <Heading entry="subject">Monasteries</Heading>
>         <Xref xref="see">
>             <Heading entry="subject">Abbeys and Monasteries</Heading>
>         </Xref>
>     </Item>
> </List>