Here are some of the design patterns you might consider:

(a) computing the column number based on the counting selected nodes in the
source tree (using count() or xsl:number) 

(b) computing the number based on the position of the node in the current
node list (the position() function)

(c) "iterating" over the nodes by head-tail recursion, maintaining a counter
as you do so (by passing a parameter on the recursive call)

(d) a two-phase transformation in which you generate the output nodes as a
plain sequence in the first pass and then number them or group them (or
colour them) in a second pass.

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



> -----Original Message-----
> From: Luke Shannon [mailto:lshannon@xxxxxxxxxxxxxxx] 
> Sent: 05 April 2005 18:57
> To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> Subject:  Something similar to managing behavior with a variable
> 
> Hello;
> 
> I'm creating a UI that writes rows of data. The background of 
> the row needs
> to changes every second row. I was doing it like this:
> 
> <tr align="left" valign="middle" class="grey1ColumnText">
> <xsl:choose>
> <xsl:when test='number($position) mod 2 != 0'>
> <xsl:attribute name="class">grey1ColumnText</xsl:attribute>
> </xsl:when>
> <xsl:otherwise>
> <xsl:attribute name="class">grey2ColumnText</xsl:attribute>
> </xsl:otherwise>
> </xsl:choose>
> </tr>
> 
> My problem now is now have a condition that determines when a 
> row is to be
> written. So, in a collection of 5 items maybe only 1 and 4 
> get written. I
> still need a way to figure out how to alternate the 
> background for the rows
> that actually get written. Position no longer does the trick.
> 
> I thought I could keep the previous background in a variable 
> like below:
> 
> <tr align="left" valign="middle" class="grey1ColumnText">
> <xsl:choose>
> <xsl:when test="$resultBK = 'grey1ColumnText'">
> <xsl:attribute name="class">grey2ColumnText</xsl:attribute>
> <xsl:variable name="resultBK" select="string('grey2ColumnText')"/>
> </xsl:when>
> <xsl:otherwise>
> <xsl:attribute name="class">grey1ColumnText</xsl:attribute>
> <xsl:variable name="resultBK" select="string('grey1ColumnText')"/>
> </xsl:otherwise>
> </xsl:choose>
> </tr>
> 
> But I have just found out you can't change the contents of a 
> global variable
> (resultBK) after it has been defined. How can I handle this?
> 
> Thanks,
> 
> Luke
> 
> Luke Shannon | Software Developer
> FutureBrand Toronto
> 
> 207 Queen's Quay, Suite 400
> Toronto, ON, M5J 1A7
> 416 642 7935 (office)