Re: [xsl] Calling a Java extension from XSLT using Saxon B

["G. Ken Holman" <gkholman@xxxxxxxxxxxxxxxxxxxx>]

At 2009-06-23 12:19 -0700, Blaine McNutt (rbmcnutt) wrote:
> I am not a Java programmer,

Nor am I ... so I look for off-the-shelf solutions for such problems.

> but I would like to use an extension to check for the existence of 
> an image file referenced by an XML file (as I believe that is the 
> only way to check for the existence of a non-XML file).

Yes.

> This topic has been discussed a lot on various aliases, and despite 
> my best efforts, I'm unable to unravel the mystery.

Your post prompted me to test an old XT stylesheet with Saxon B and 
it works!  It would seem that Mike has the foresight to support other 
implementations' use of Java extensions.

I hope the example below helps as it does not involve writing any Java code.

. . . . . . . . . Ken

X:\samp>type exists.xml
<?xml version="1.0"?>
<files>
<file>exists.xml</file>
<file>exists.junk</file>
<file>exists.xsl</file>
</files>
X:\samp>type exists.xsl
<?xml version="1.0"?><!--exists.xsl-->
<!--XSLT 1.0 - http://www.CraneSoftwrights.com/training -->
<!DOCTYPE xsl:stylesheet [ <!ENTITY nl "&#xd;&#xa;"> ]>
<xsl:stylesheet version="1.0"
         xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
         xmlns:file="http://www.jclark.com/xt/java/java.io.File";>

<xsl:output method="text"/>

<xsl:template match="/">
  <xsl:if test="not( function-available('file:exists') and
                     function-available('file:new') )">
    <xsl:message terminate="yes">
      <xsl:text>Required Java file facilities </xsl:text>
      <xsl:text>are not available</xsl:text>
    </xsl:message>
  </xsl:if>
  <xsl:for-each select="//file">         <!--process each file-->
    <xsl:text>File </xsl:text><xsl:value-of select="."/>
    <xsl:text>: </xsl:text>              <!--display file name-->
    <xsl:choose>                          <!--report existence-->
      <xsl:when test="file:exists(file:new(string(.)))">
        <xsl:text>exists&nl;</xsl:text>
      </xsl:when>
      <xsl:otherwise>
        <xsl:text>does not exist&nl;</xsl:text>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:for-each>
</xsl:template>

</xsl:stylesheet>

X:\samp>java -jar p:\xml\xslt\saxon9\saxon9.jar exists.xml exists.xsl
Warning: at xsl:stylesheet on line 6 column 66 of exists.xsl:
  Running an XSLT 1.0 stylesheet with an XSLT 2.0 processor
File exists.xml: exists
File exists.junk: does not exist
File exists.xsl: exists

X:\samp>


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