Sort XML file by attribute

Question

I have the following XML code:

<Group>
    <GElement code="x">
        <Group>
            <GElement code="x">
                <fname>a</fname>
                <lname>b</lname>
            </GElement>
            <GElement code ="f">
                <fname>fa</fname>
            </GElement>
        </Group>
    </GElement>
    <GElement code ="f">
    </GElement>
</Group>

I would like the result to be sorted by "code":

<Group>
    <GElement code ="f">
    </GElement>
    <GElement code="x">
        <Group>
            <GElement code ="f">
                <fname>fa</fname>
            </GElement>
            <GElement code="x">
                <fname>a</fname>
                <lname>b</lname>
            </GElement>
        </Group>
    </GElement>
</Group>

The depth of the tree can be infinite, i.e. GElement may have a different group, etc.

Any ideas?

Answer 1

Use XslCompiledTransform( see MSDN ) to apply this style to your XML document:

<xsl:stylesheet
  version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
>
  <!-- the identity template copies everything verbatim -->
  <xsl:template match="node()|@*">
    <xsl:copy>
      <xsl:apply-templates select="node()|@*" />
    </xsl:copy>
  </xsl:template>

  <!-- special template for <Group> that sorts its children -->
  <xsl:template match="Group">
    <xsl:copy>
      <xsl:copy-of select="@*" /> <!-- copy attributes, if any -->
      <xsl:apply-templates select="GElement">
        <xsl:sort select="@code" />
      </xsl:apply-templates>
    </xsl:copy>
  </xsl:template>
</xsl:stylesheet>

The nesting depth of the XML tree can be arbitrary.