Grouping with XSLT 1.0

beat79 · January 29th, 2014, 01:28 PM

I have an XML of that kind:

Code:

    <?xml version="1.0" encoding="UTF-8"?>
    <Returns>
     <Row>
      <Application>
       app1
      </Application>
      <Component>
       comp1
      </Component>
      <Version>
       1
      </Version>
     </Row>
     <Row>
      <Application>
       app1
      </Application>
      <Component>
       comp2
      </Component>
      <Version>
       1
      </Version>
     </Row>
     <Row>
      <Application>
       app1
      </Application>
      <Component>
       comp1
      </Component>
      <Version>
       2
      </Version>
     </Row>
     <Row>
      <Application>
       app1
      </Application>
      <Component>
       comp2
      </Component>
      <Version>
       2
      </Version>
     </Row>
     <Row>
      <Application>
       app2
      </Application>
      <Component>
       comp1
      </Component>
      <Version>
       1
      </Version>
     </Row>
      <Row>
      <Application>
       app2
      </Application>
      <Component>
       comp2
      </Component>
      <Version>
       1
      </Version>
     </Row>
      <Row>
      <Application>
       app2
      </Application>
      <Component>
       comp1
      </Component>
      <Version>
       2
      </Version>
     </Row>
      <Row>
      <Application>
       app2
      </Application>
      <Component>
       comp2
      </Component>
      <Version>
       2
      </Version>
     </Row>
    </Returns>

I need to transform it to something like this:

Code:

        <?xml version="1.0" encoding="UTF-8"?>
    <Components>
       <Component application="app1" version="2" name="comp1"/>
       <Component application="app1" version="2" name="comp2"/>
       <Component application="app2" version="2" name="comp1"/>
       <Component application="app2" version="2" name="comp2"/>
    </Components>

The goal is to show only the components that belong to the latest version of each application.

I wrote this XSL template that uses muenchian grouping:

Code:

    <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="xml" indent="yes" />
    <xsl:key name="application" match="Row" use="Application" />
    <xsl:template match="Returns">
        <Components>
            <xsl:apply-templates select="Row[generate-id(.)=generate-id(key('application',Application)[1])]">
            </xsl:apply-templates>
        </Components>
    </xsl:template>
     <xsl:template match="Row">
            <xsl:for-each select="key('application', Application)">
                        <xsl:sort select="Version" order="descending"/>
                      <xsl:for-each select="Version">
                        <Component application="{normalize-space(../Application)}" version="{normalize-space(current())}" name="{normalize-space(../Component)}"></Component>                      
                     </xsl:for-each>
            </xsl:for-each>
    </xsl:template>
</xsl:stylesheet>

And now I get this output:

Code:

    <?xml version="1.0" encoding="UTF-8"?>
    <Components>
       <Component application="app1" version="2" name="comp1"/>
       <Component application="app1" version="2" name="comp2"/>
       <Component application="app1" version="1" name="comp1"/>
       <Component application="app1" version="1" name="comp2"/>
       <Component application="app2" version="2" name="comp1"/>
       <Component application="app2" version="2" name="comp2"/>
       <Component application="app2" version="1" name="comp1"/>
       <Component application="app2" version="1" name="comp2"/>
    </Components>

How can I filter the components to get only the ones that belong to the latest version of the same application?

Thanks,
Valerio