Using the self Axis

The self axis contains just the context node. In fact, one of the XPath abbreviations that youll see later is that you can abbreviate self::node() as ..

This is a useful axis to know about, because as you recall from Chapter 4, if you omit the axis, the default is child:: , and sometimes you want to refer to the current node instead. For example, [self::PLANET] is true only if the context node is a <PLANET> element.

In the following example, I combine the templates for < NAME > and <MASS> elements into one template. Because those elements are formatted differently, however, I need to tell them apart inside the same template, and I can do that by checking self::NAME , which returns a non-empty node set if the context node is a <NAME> element, and self::MASS , which returns a non-empty node set if the context node is a <MASS> element:

 <xsl:template match="PLANET">         <TR>            <TD><xsl:apply-templates select="NAME"/></TD>            <TD><xsl:apply-templates select="MASS"/></TD>            <TD><xsl:apply-templates select="RADIUS"/></TD>            <TD><xsl:apply-templates select="DAY"/></TD>         </TR>     </xsl:template>      <xsl:template match="NAME  MASS">          <xsl:if test="self::NAME">              <xsl:value-of select="."/>          </xsl:if>          <xsl:if test="self::MASS">              <xsl:value-of select="."/>              <xsl:text> </xsl:text>              <xsl:value-of select="@UNITS"/>          </xsl:if>      </xsl:template>          .          .          .

That completes our look at the new XPath axes. Its time to get to some examples.