Remove sibling elements according to the value of the attribute of another element

[Patrizio Trinchini]

Hi All,

given the following source XML document:

<?xml version="1.0" encoding="UTF-8"?>
<sample xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNameSpaceSchemaLocation="sample.xsd">
<parent-element>
<child-element name="AAA" value="XXX"/>
<sibling-element-1 id="001">Sibling 1 of child-element AAA</sibling-element-1>
<sibling-element-2 id="002">Sibling 2 of child-element AAA</sibling-element-2>
</parent-element>
<parent-element>
<child-element name="BBB" value="XXX"/>
<sibling-element-1 id="003">Sibling 1 of child-element BBB</sibling-element-1>
<sibling-element-2 id="004">Sibling 2 of child-element BBB</sibling-element-2>
</parent-element>
<parent-element>
<child-element name="CCC" value="XXX"/>
<sibling-element-1 id="005">Sibling 1 of child-element CCC</sibling-element-1>
<sibling-element-2 id="006">Sibling 2 of child-element CCC</sibling-element-2>
</parent-element>
</sample>

I would otain the following result:

<?xml version="1.0" encoding="UTF-16"?>
<sample xsi:noNameSpaceSchemaLocation="sample.xsd"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<parent-element>
<child-element name="AAA" value="aNewValue1"></child-element>
<sibling-element-1 id="001">Sibling 1</sibling-element-1>
<sibling-element-2 id="002">Sibling 2</sibling-element-2>
</parent-element>
<parent-element>
<child-element name="BBB" value="aNewValue2"></child-element>
<sibling-element-1 id="010">Sibling 1</sibling-element-1>
<sibling-element-2 id="020">Sibling 2</sibling-element-2>
</parent-element>
<parent-element>
<child-element name="CCC" value="aNewValue3"></child-element>
</parent-element>
</sample>

I'm able to get it using the following XSLT transformer:

<?xml version="1.0"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0">
<xsl:output indent="yes"/>
<xsl:template match="@*|node()">
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="child-element[@name = 'AAA']/@value">
<xsl:attribute name="{name()}">aNewValue1</xsl:attribute>
</xsl:template>
<xsl:template match="child-element[@name = 'BBB']/@value">
<xsl:attribute name="{name()}">aNewValue2</xsl:attribute>
</xsl:template>
<xsl:template match="child-element[@name = 'CCC']/@value">
<xsl:attribute name="{name()}">aNewValue3</xsl:attribute>
</xsl:template>
<xsl:template match="parent-element/sibling-element-1">
<xsl:if test="preceding-sibling::child-element[@name != 'CCC']">
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:if>
</xsl:template>
<xsl:template match="parent-element/sibling-element-2">
<xsl:if test="preceding-sibling::child-element[@name != 'CCC']">
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:if>
</xsl:template>
</xsl:stylesheet>

Do you think that this is a valid approach or maybe there is a better
one, especially for the removal of elements according to the value of
the name attribute of the sibling child-element ?

Thanks a lot for any suggestion.

Patrizio

[Paul Clapham]

If you had asked how to remove elements from an XML document, I would have suggested using an XSLT identity transformation plus a template that failed to copy the elements you wanted to remove. And that's what you have there. So yes, I approve.

Besides, it works, right?