Xsl: How can I Group and sort based on sum?

Question

I have the below xml

Answer 1

Something like this (I have re-constructing your code, as it was missing quite a lot):

This XSLT transformation:

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

 <xsl:param name="pSortBy" select="'Pass'"/>

 <xsl:key name="kResultByOwner" match="Result"
  use="@Owner"/>

    <xsl:template match="/">
        <table>
            <xsl:for-each select=
            "ResultCollection/Result
                 [generate-id(.) 
                 = 
                  generate-id(key('kResultByOwner', @Owner)[1])
                  ]">
                 <xsl:sort data-type="number" select=
                "sum(key('kResultByOwner', @Owner)
                               /@*[name()=$pSortBy])"/> 

                <xsl:variable name="totFailures" select=
                "sum(/ResultCollection/Result
                          [@Owner=current()/@Owner]
                              /@Fail
               )" />
                <xsl:variable name="totPass" select=
                "sum(/ResultCollection/Result
                           [@Owner=current()/@Owner]
                              /@Pass
               )" />

                <xsl:variable name="total" select=
                   "$totPass+$totFailures" />
                <tr>
                    <td>
                        <xsl:value-of select="current()/@Owner"/>
                    </td>
                    <td>
                        <xsl:value-of select="$total"/>
                    </td>
                    <td>
                        <xsl:value-of select="$totPass"/>
                    </td>
                    <td>
                        <xsl:value-of select="$totFailures"/>
                    </td>
                </tr>
            </xsl:for-each>
        </table>
    </xsl:template>
</xsl:stylesheet>

when applied on the originally provided XML document:

<ResultCollection>
    <Result Id="551550" Pass="23" Fail="0" Owner="Dong"/>
    <Result Id="551565" Pass="4" Fail="3" Owner="Dong"/>
    <Result Id="551567" Pass="61" Fail="0" Owner="Mei"/>
    <Result Id="551580" Pass="10" Fail="1" Owner="Dong"/>
    <Result Id="551580" Pass="0" Fail="4" Owner="Sen"/>
    <Result Id="551548" Pass="1" Fail="12" Owner="Sen"/>
</ResultCollection>

produces the wanted result):

Sen        17    1  16
Dong       41   37   4
Mei        61   61   0

Do note the following:

1. The summation of the values of the @Pass or the @Fail attribute for the elements that belong only to the current group (the use of the key() function).

2. The use of the <xsl:sort .../> instruction to sort by the required sums.

3. The use of a global parameter named pSortBy, which contains the name of the attribute on the sums of which to sort.

4. The use of the XSLT function current()