sorting elements by attribute on a simple nested structure - xslt

Question

I'm still struggling to get my head around a lot of XSLT but have a specific question.
I have a simple nested structure that I want to sort by an attribute (name).
The file has a single root node and then a series of nested nodes. I need to have all the nodes under root sorted within the level they are. The hierarchy is nested to an unspecified level.
The input:
<?xml version="1.0" encoding="UTF-8"?>
<root>
<node name="A">
<node name="C"/>
<node name="B"/>
</node>
<node name="F"/>
<node name="E"/>
</root>
Needs to be transformed into:
<?xml version="1.0" encoding="UTF-8"?>
<root>
<node name="A">
<node name="B"/>
<node name="C"/>
</node>
<node name="E"/>
<node name="F"/>
</root>
I won't bore you with my feable attempts at solving this.

Answer 1

Assuming you do wish the elements to stay within the level they are currently in, firstly, you would need a template to match any element
<xsl:template match="*">
Then you would use xsl:copy to copy the element, and xsl:copy-of to copy any attributes
<xsl:copy>
<xsl:copy-of select="#*"/>
... more code here...
</xsl:copy>
And within the xsl:copy you would then use xsl:apply-templates to process the child elements, along with xsl:sort to select the order
<xsl:apply-templates select="*">
<xsl:sort select="#name" />
</xsl:apply-templates>
Put this altogether gives you this
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes" />
<xsl:template match="*">
<xsl:copy>
<xsl:copy-of select="#*"/>
<xsl:apply-templates select="*">
<xsl:sort select="#name" />
</xsl:apply-templates>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>
When applied to your input XML the following is output
<root>
<node name="A">
<node name="B"/>
<node name="C"/>
</node>
<node name="E"/>
<node name="F"/>
</root>

Answer 2

This answer is similar to Tim C's, but is just using an identity transform with an xsl:sort. This way you don't loose comments or processing instructions if they're present.
XSLT 1.0
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:template match="#*|node()">
<xsl:copy>
<xsl:apply-templates select="#*|node()">
<xsl:sort select="#name"/>
</xsl:apply-templates>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>