XSLT value() and position() give incorrect indices

Question

Can someone please explain me why I get the following output applying the follwoing xsl-file to the xml-file.

<?xml version="1.0" encoding="ISO-8859-1"?>
<source>    
    <number>1</number> 
    <number>2</number> 
    <number>3</number> 
    <number>4</number> 
    <number>5</number> 
    <number>6</number> 
    <number>7</number> 
    <number>8</number> 
</source>

====================================

<?xml version="1.0" encoding="ISO-8859-1"?>
<xsl:stylesheet version = '1.0' xmlns:xsl='http://www.w3.org/1999/XSL/Transform'>
<xsl:template match="number">
   <p>
   <xsl:value-of select="position()"/>
   <xsl:text> of </xsl:text>
   <xsl:value-of select="last()"/>
   </p>
</xsl:template>
</xsl:stylesheet>

======================================

<p>2 of 17</p> 
    <p>4 of 17</p> 
    <p>6 of 17</p> 
    <p>8 of 17</p> 
    <p>10 of 17</p> 
    <p>12 of 17</p> 
    <p>14 of 17</p> 
    <p>16 of 17</p> 

I don't quite get why the output is not 1 of 8, 2 of 8 and so on.

Answer 1

Try adding strip-space as shown below:

<?xml version="1.0" encoding="ISO-8859-1"?>
<xsl:stylesheet version = '1.0' xmlns:xsl='http://www.w3.org/1999/XSL/Transform'>
  <xsl:strip-space elements="*"/>
  <xsl:template match="number">
   <p>
   <xsl:value-of select="position()"/>
   <xsl:text> of </xsl:text>
     <xsl:value-of select="last()"/>
   </p>
</xsl:template>
</xsl:stylesheet>

This gives the following output:

<p>1 of 8</p>
<p>2 of 8</p>
<p>3 of 8</p>
<p>4 of 8</p>
<p>5 of 8</p>
<p>6 of 8</p>
<p>7 of 8</p>
<p>8 of 8</p>

This is due to whitespace issues, as described in this document. Basically the nodeset contains whitespace nodes that are not matched by your template, but contribute to the index of each node.