Using the parent Axis

The parent axis contains the parent (and just the parent) of the context node, if there is one.

Say that I want to change the content of Earths <MASS> element to The mass of Earth is set to 1. The following template does that by checking whether a <MASS> elements parent <PLANET> contains a < NAME > whose string value is Earth:

Listing 7.12 Using the parent Axis

 <?xml version="1.0"?>  <xsl:stylesheet version="1.0"  xmlns:xsl="http://www.w3.org/1999/XSL/Transform">  <xsl:output method="xml"/>    <xsl:template match="@*node()">      <xsl:copy>        <xsl:apply-templates select="@*node()"/>      </xsl:copy>    </xsl:template>    <xsl:template match="MASS[parent::node()/NAME='Earth']">      <MASS>The mass of Earth is set to 1.</MASS>    </xsl:template>  </xsl:stylesheet>

And heres the result:

 <?xml version="1.0" encoding="utf-8"?>  <?xml-stylesheet type="text/xml" href="planets.xsl"?>  <PLANETS>      <PLANET>          <NAME>Mercury</NAME>          <MASS UNITS="(Earth = 1)">.0553</MASS>          <DAY UNITS="days">58.65</DAY>          <RADIUS UNITS="miles">1516</RADIUS>          <DENSITY UNITS="(Earth = 1)">.983</DENSITY>          <DISTANCE UNITS="million miles">43.4</DISTANCE><!--At perihelion-->      </PLANET>      <PLANET>          <NAME>Venus</NAME>          <MASS UNITS="(Earth = 1)">.815</MASS>          <DAY UNITS="days">116.75</DAY>          <RADIUS UNITS="miles">3716</RADIUS>          <DENSITY UNITS="(Earth = 1)">.943</DENSITY>          <DISTANCE UNITS="million miles">66.8</DISTANCE><!--At perihelion-->      </PLANET>      <PLANET>          <NAME>Earth</NAME>          <MASS>The mass of Earth is set to 1.</MASS>          <DAY UNITS="days">1</DAY>          <RADIUS UNITS="miles">2107</RADIUS>          <DENSITY UNITS="(Earth = 1)">1</DENSITY>          <DISTANCE UNITS="million miles">128.4</DISTANCE><!--At perihelion-->      </PLANET>  </PLANETS>