Re: [xsl] A better way to build a comma-delimited list

[Joerg Heinicke <joerg.heinicke@xxxxxx>]

Hello John,

>       <xsl:for-each select="$dbdef">
>          <xsl:if test="key('dbdef-cols', $dbcolumn)">
>             <xsl:value-of select="$dbcolumn"/>
>             <xsl:if test="$p &lt; $l">
>                <xsl:text>, </xsl:text>
>             </xsl:if>
>          </xsl:if>
>       </xsl:for-each>

instead of the for-each + if you can write one for-each with predicate:

<xsl:for-each select="$dbdef[key('dbdef-cols', $dbcolumn)]">

Now the correct nodeset is selected and position() and last() will work. 
But they must refer to the inner for-each, so you can't use $p and $l, 
but <xsl:if test="position() != last()">.

So, you have then

<xsl:for-each select="$dbdef[key('dbdef-cols', $dbcolumn)]">
  <xsl:value-of select="$dbcolumn"/>
  <xsl:if test="position() != last()">
    <xsl:text>, </xsl:text>
  </xsl:if>
</xsl:for-each>

Regards,

Joerg

John Sands schrieb:
> I have some XSLT that builds a SQL select statement from several input
> documents. Here's a fragment that builds the column list by getting
> each distinct column name from a separate file ($pbsdef) and checking
> that is is defined in another file (referenced by variable $dbdef).
>
>    <xsl:text>select </xsl:text>
>    <xsl:for-each select="document($pbsdef)/pbsdef/column[not(@dbcolumn=preceding-sibling::column/@dbcolumn)]">
>       <xsl:variable name="p" select="position()"/>
>       <xsl:variable name="l" select="last()"/>
>       <xsl:variable name="dbcolumn" select="@dbcolumn"/>
>       <xsl:for-each select="$dbdef">
>          <xsl:if test="key('dbdef-cols', $dbcolumn)">
>             <xsl:value-of select="$dbcolumn"/>
>             <xsl:if test="$p &lt; $l">
>                <xsl:text>, </xsl:text>
>             </xsl:if>
>          </xsl:if>
>       </xsl:for-each>
>    </xsl:for-each>
>
> The output of this fragment might be:
>
>  select col1, col2, col3
>
> This all works fine, except for one case - where the last column is
> not found in the $dbdef file (where the 'if test=key' fails). Then I
> get:
>
>  select col1, col2,
>
> The position() < last() test doesn't work here. Can someone see a
> better way to avoid that last comma?
>
> Thanks,
> John Sands


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