Question

I need to merge this node together, but it has to be merged with the parent that has an attribute method="a"

Input:

<myroot>
    <elem name="a" creationDate="">
        <list id="xxx" ver="uu">
            <nodeA id="a">
                <fruit id="small">
                    <orange id="x" method="create">                       
                        <color>Orange</color>                                               
                    </orange>
                </fruit>     
                <fruit id="small" method="a">
                    <kiwi id="y" method="create">                        
                        <color>Red</color>
                        <type>sour</type>                       
                    </kiwi>                    
                </fruit>
                <fruit id="large" method="a">
                    <melon id="y" method="create">
                        <attributes>
                            <color>Green</color>
                            <type>sweet</type>
                        </attributes>
                    </melon>                    
                </fruit>
            </nodeA>
        </list>
    </elem>
</myroot>

my XSL file:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">
    <xsl:output indent="yes"/>
    <xsl:strip-space elements="*"/>

    <xsl:template match="@* | node()">
        <xsl:copy>
            <xsl:apply-templates select="@* , node()"/>
        </xsl:copy>
    </xsl:template>

    <xsl:template match="list">
        <xsl:copy>
            <xsl:copy-of select="@*"/>
            <xsl:for-each-group select="/*/*/*/*" group-by="@id">
                <xsl:copy>
                    <xsl:copy-of select="@*"/>
                    <xsl:for-each-group select="current-group()/*" group-by="concat(local-name(), '|', @id)">
                        <xsl:copy>
                            <xsl:apply-templates select="@*, *, (current-group() except .)/*"/>
                        </xsl:copy>
                    </xsl:for-each-group>
                </xsl:copy>
            </xsl:for-each-group>
        </xsl:copy>
    </xsl:template>
</xsl:stylesheet>

my output:

<myroot>
    <elem name="a" creationDate="">
        <list id="xxx" ver="uu">
            <nodeA id="a">
                <fruit id="small">            
                    <orange id="x" method="create">                       
                        <color>Orange</color>                                               
                    </orange>
                    <kiwi id="y" method="create">                        
                        <color>Red</color>
                        <type>sour</type>                       
                    </kiwi>                    
                </fruit>     

                <fruit id="large" method="a">
                    <melon id="y" method="create">
                        <attributes>
                            <color>Green</color>
                            <type>sweet</type>
                        </attributes>
                    </melon>                    
                </fruit>
            </nodeA>
        </list>
    </elem>
</myroot>

Expected Output:

<myroot>
    <elem name="a" creationDate="">
        <list id="xxx" ver="uu">
            <nodeA id="a">
                <fruit id="small" method="a"> <!-- this is the correct merge where the merged is in parent that has a method -->
                    <kiwi id="y" method="create">                        
                        <color>Red</color>
                        <type>sour</type>                       
                    </kiwi>
                    <orange id="x" method="create">                       
                        <color>Orange</color>                                               
                    </orange>
                </fruit>     

                <fruit id="large" method="a">
                    <melon id="y" method="create">
                        <attributes>
                            <color>Green</color>
                            <type>sweet</type>
                        </attributes>
                    </melon>                    
                </fruit>
            </nodeA>
        </list>
    </elem>
</myroot>

As we can see my transformation only combine it together and does not consider the method. How to change it so it will be merged to parent that has method="a" in the example it is <fruit id="small" method="a">

Thank you.
John

Answer 1

Within an <xsl:for-each-group> element the context item is just the first element of the group, so select="@*" will copy just the attributes of the first element. To get a copy of all differently-named attributes in any element you need to access current-group()/@*.

There is also no need to select="*, (current-group() except .)/*" as it is equivalent to select="current-group()/*".

The complete stylesheet looks like this

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">

  <xsl:output method="xml" indent="yes" />
  <xsl:strip-space elements="*" />

  <xsl:template match="@* | node()">
    <xsl:copy>
      <xsl:apply-templates select="@*, node()" />
    </xsl:copy>
  </xsl:template>

  <xsl:template match="list">
    <xsl:copy>
      <xsl:copy-of select="@*" />
      <xsl:apply-templates select="*" />
    </xsl:copy>
  </xsl:template>

  <xsl:template match="list/*">

      <xsl:copy>

        <xsl:copy-of select="@*" />

        <xsl:for-each-group select="*" group-by="concat(local-name(), '|', @id)">
          <xsl:copy>
            <xsl:copy-of select="current-group()/@*" />
            <xsl:copy-of select="current-group()/*" />
          </xsl:copy>
        </xsl:for-each-group>

      </xsl:copy>

  </xsl:template>

</xsl:stylesheet>