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

[John Sands <WonkoWatson@xxxxxxxxx>]

Hi Joerg,

> <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>

I loved the solution because it would fix the problem AND make the
code shorter. Unfortunately it doesn't work because position() and
last() are both 1 so I get:

 select col1col2col3

John




> -----Original Message-----
> From: Joerg Heinicke  <joerg.heinicke@xxxxxx>
> Sent: Wednesday, May 15, 2002, 3:15:02 AM,
> Subject: [xsl] A better way to build a comma-delimited list

> 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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