Question

I have a set of xml nodes with identical node names but one attribute that differentiate them, and an amount attribute:

<exampleNode typeOfnode="1" amount="100"/>
<exampleNode typeOfnode="1" amount="540"/>
<exampleNode typeOfnode="2" amount="200"/>
<exampleNode typeOfnode="2" amount="200"/>
<exampleNode typeOfnode="3" amount="10"/>
<exampleNode typeOfnode="3" amount="1"/>
<exampleNode typeOfnode="3" amount="110"/>
<exampleNode typeOfnode="3" amount="110"/>
<exampleNode typeOfnode="4" amount="110"/>

I’m using a recursive template to calculate the sum of the amounts, but only want to do that for a specific typeOfNode. Here is the code I’m using to call the template:

<xsl:call-template name="addition">
    <xsl:with-param name="currentValue">0</xsl:with-param>
    <xsl:with-param name="counter"><xsl:value-of select="count(//exampleNode[@typeOfnode= '1'])"/></xsl:with-param>
    <xsl:with-param name="typeOfnode">1</xsl:with-param>
</xsl:call-template>

<xsl:template name="addition">
    <xsl:param name="currentValue"/>
    <xsl:param name="counter"/>
    <xsl:param name="typeOfNode"/>
    <xsl:variable name="amount" select="//exampleNode[@typeOfNode = '$typeOfnode' and $counter]/@amount"/>
    <xsl:variable name="recursiveValue" select="number($recursiveValue + $amount)"/>
    <xsl:choose>
        <xsl:when test="number($counter - 1) > 0">
            <xsl:call-template name="addition">
                <xsl:with-param name="currentValue">
                    <xsl:value-of select="$recursiveValue"/>
                </xsl:with-param>
                <xsl:with-param name="counter">
                    <xsl:value-of select="number($counter - 1)"/>
                </xsl:with-param>
                <xsl:with-param name="agreementType">
                    <xsl:value-of select="$agreementType"/>
                </xsl:with-param>
            </xsl:call-template>
        </xsl:when>
        <xsl:otherwise>
            <xsl:value-of select="$recursiveValue"/>
        </xsl:otherwise>
    </xsl:choose>
</xsl:template>

Having debugged through wiTH XMLspy, the amount variable is not being set, and I assume it’s because I’m screwing up the query. Anybody have any idea what I’m doing wrong?

Answer 1

for a quick answer, see the last code block. For some comments on the code, read from here.

1. How about fixing the recursive loop by using currentValue iso recursiveValue to seed the recursiveValue:

   <xsl:variable name="recursiveValue" select="number($currentValue + $amount)"/>
   

2. There are some XSLT errors here, e.g. this does not look like it will work:

   <xsl:variable name="amount" select="//exampleNode[@typeOfNode = '$typeOfnode' and $counter]/@amount"/>
   

   if you mean to say “amount is the @amount of the $counter-th /exampleNode with @typeOfNode=$typeofnode, this is not the way.

   • ‘escaping’ the variable will not work, it will compare to the literal value “$typeOfnode”.
   • “and $counter” always evaluates to true, unless $counter is not set. Try “position()=$typeOfnode” but be aware that position will be the position of the current exampleNode in the entire set of exampleNode siblings. This could be fixed by using an intermediate variable where you ‘copy’ the exampleNodes that pass the filter, into which you test for the index using the $counter variable.

3. Your snippet

       <xsl:with-param name="agreementType">
         <xsl:value-of select="$agreementType"/>
       </xsl:with-param>
   

   is probably missing some confuscation, did you mean typeOfnode iso agreementType? 😀

All of that aside, there are simpler solutions. for instance a quite direct:

<xsl:value-of select="sum(exampleNode[@typeOfnode='1']/@amount)"/>