Sablotron XSLT Functions

The Sablotron extension provides PHP scripts with the ability to apply XSLT stylesheets to XML data in a variety of ways. In order to have access to these functions in PHP, you need to compile PHP with the --with-sablot=[DIR] configure option. The Sablotron library can be downloaded from http://www.gingerall.com.

For FAQs, tutorials, and specifications regarding XML and XSL, two good places to start are http://xml.coverpages.org and http://www.xml.org.

There are various levels at which one may use the Sablotron functionality. Perhaps the easiest allows you to tell PHP to apply a stylesheet to all output between two function calls: anything which PHP outputs between a call to xslt_outputbegintransform() and xslt_outputendtransform() will have the requested stylesheet applied to it. The second, slightly lower-level method, involves putting your stylesheet into one string, your XML data into another, and passing both strings to xslt_process() ; the resulting document will be placed into a third string parameter. Another method also allows you to apply a stylesheet to an XML document with a single function call. Using xslt_transform() , you supply the URIs of a stylesheet file, an XML document file, and a result buffer, plus optionally some parameters and arguments. A result buffer is a section of Sablotron's internal memory which is accessible via a name using the Sablotron-specific 'arg:' URI scheme (see below for more information on supported URI schemes). With most of these functions, if no buffer URI is given, a default result buffer name of 'arg:/_result' will be used. The fourth, lowest-level method is suitable, for instance, when you need to use Sablotron's logging functionality. In this method, you create a parser with xslt_create() , set any logging (if needed) with xslt_openlog() , and then apply the transformation itself with xslt_run() . The results then need to be retrieved using xslt_fetch_result() .

Sablotron currently supports two URI schemes: 'file:' for files which can be found on the server filesystem, and 'arg:' for naming internal document buffers. Under Windows environments, if you need to supply a drive letter as part of a 'file:' URI, the format must follow the general syntax of 'file://c:/path/to/document.xml'. In other cases, the 'file:' is optional.

For the examples provided, you can download the file located at http://www.slashdot.org/slashdot.xml for use as the XML document. The simple XSL used to test these examples is provided below; for the purpose of testing it was placed in the file slashdot.xsl in the same directory as the PHP scripts and XML file.

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="html" indent="yes"/>
 <xsl:param name="generated-for"></xsl:param>
 <xsl:template match="/">
  <xsl:if test="$generated-for">
    <h3>Generated for: <xsl:value-of select="$generated-for"></xsl:value-of></h3>
  </xsl:if>
  <xsl:for-each select="//story">
    <A>
       <xsl:attribute name="HREF"><xsl:value-of select='url' /></xsl:attribute>
       <xsl:attribute name="NAME">testname</xsl:attribute>
       <xsl:value-of select="title"/>
    </A> By <xsl:value-of select="author"/> at <xsl:value-of select="time"/>
    <HR/>
  </xsl:for-each>
 </xsl:template>
</xsl:stylesheet>