XML sorting

[pisicuta]

People must get sick of answering questions on sorting, but I haven't found an example on the web that matches my situation (Maybe I am asking the wrong question). My XML file has this sort of structure

<?xml version="1.0"?>
<Building>
	<Block>
		<Id>Ba2150</Id>
		<Elevation>140</Elevation>
		<Piece>
			<Description>Rustic</Description>
			<Elevation>180</Elevation>
			<Qty>1</Qty>
		</Piece>
		<Piece>
			<Description>Rustic</Description>
			<Elevation>1870</Elevation>
			<Qty>1</Qty>
		</Piece>
		<Piece>
			<Description>Red</Description>
			<Elevation>500</Elevation>
			<Qty>1</Qty>
		</Piece>
		<Piece>
			<Description>Blue</Description>
			<Elevation>1430</Elevation>
			<Qty>1</Qty>
		</Piece>
		<Piece>
			<Description>Side</Description>
			<Elevation>140</Elevation>
			<Qty>2</Qty>
		</Piece>
		<Piece>
			<Description>Bottom</Description>
			<Elevation>140</Elevation>
			<Qty>1</Qty>
		</Piece>
		<Piece>
			<Description>Back</Description>
			<Elevation>140</Elevation>
			<Qty>1</Qty>
		</Piece>
		<Piece>
			<Description>Top</Description>
			<Elevation>2190</Elevation>
			<Qty>1</Qty>
		</Piece>
	</Block>
</Building>

All I want to do is sort the pieces within the blocks and output the whole lot. I can sort the blocks, I can sort the pieces and lose the blocks and I can sort the pieces and keep the block tags, but not the block data. My current xsl is

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="xml" indent="yes"/>

 <xsl:template match="Building">
 <xsl:copy>
      <xsl:apply-templates select="Block">
	<xsl:sort select="Elevation" data-type="number"/> <!-- not really necessary, already sorted -->
     </xsl:apply-templates>
</xsl:copy>
</xsl:template>

  <xsl:template match="Block">
    <xsl:copy>
	<xsl:apply-templates select="Piece">
		<xsl:sort select="Elevation" data-type="number"/>
	</xsl:apply-templates>
    </xsl:copy>
  </xsl:template>

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

Any help would be greatly appreciated

[Dormilich]

just for a better understanding, what shall it look like afterwards?

[pisicuta]

Sorry, I didn't it clear what the output should be. The output should look like this, so the Piece elements are in ascending elevation order:

<?xml version="1.0"?>
<Building>
	<Block>
		<Id>Ba2150</Id>
		<Elevation>140</Elevation>
		<Piece>
			<Description>Side</Description>
			<Elevation>140</Elevation>
			<Qty>2</Qty>
		</Piece>
		<Piece>
			<Description>Bottom</Description>
			<Elevation>140</Elevation>
			<Qty>1</Qty>
		</Piece>
		<Piece>
			<Description>Back</Description>
			<Elevation>140</Elevation>
			<Qty>1</Qty>
		</Piece>
		<Piece>
			<Description>Rustic</Description>
			<Elevation>180</Elevation>
			<Qty>1</Qty>
		</Piece>
		<Piece>
			<Description>Red</Description>
			<Elevation>500</Elevation>
			<Qty>1</Qty>
		</Piece>
		<Piece>
			<Description>Blue</Description>
			<Elevation>1430</Elevation>
			<Qty>1</Qty>
		</Piece>		
		<Piece>
			<Description>Rustic</Description>
			<Elevation>1870</Elevation>
			<Qty>1</Qty>
		</Piece>
		<Piece>
			<Description>Top</Description>
			<Elevation>2190</Elevation>
			<Qty>1</Qty>
		</Piece>
	</Block>
</Building>

[Dormilich]

maybe Munchian sorting can help.

[pisicuta]

Spent all day with Munchian sorting and am no further forward. In fact I've probably got a bigger headache. I just can't get any elements copied from the <Piece>..</Piece> nodes and have the Block details as well. I end up with:

<Building>
	<Block>
		<Id>Ba2150</Id>
		<Elevation>140</Elevation>
                <Piece />
		<Piece />
                <Piece />
		<Piece />
                <Piece />
		<Piece />
                <Piece />
		<Piece />
	<Block>
<Building>

[Dormilich]

I wish jkmyoung were here, he’s the sort & copy expert …

I’ll try if I can shed some light on it, but it will take some time.

[pisicuta]

Solution

I managed to get the answer from somewhere else. For all those interested, here it is.

<xsl:stylesheet version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform" >
  <xsl:template match="Building">
    <xsl:copy>
      <xsl:copy-of select="@*" /> <!-- copy attributes-->
      <xsl:apply-templates />
    </xsl:copy>
  </xsl:template>
  
  <xsl:template match="Block">
    <xsl:copy>
      <xsl:copy-of select="@*" /> <!-- copy attributes-->
      <xsl:copy-of select="*[local-name()!='Piece']" />
      <xsl:for-each select="Piece">
        <!-- [url]http://www.w3.org/TR/xslt#sorting[/url] -->
        <xsl:sort select="Elevation" data-type="number" order="ascending" />
        <xsl:copy-of select="." />
      </xsl:for-each>
    </xsl:copy>
  </xsl:template>
  
    <xsl:template match="Panel">
        <xsl:copy-of select="." />
  </xsl:template>
</xsl:stylesheet>