Sablotron XSLT Extensions Readme File
=====================================

1. Building
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Extension elements and functions as defined by XSLT 1.0 are 
implemented in Sablotron since the version 0.80. Sablotron recognizes
the extension element <http://www.exslt.org/functions/script> as 
suggested by exslt.org. There are some exceptions described later in 
this document. Please note, that this feature is still supposed to be 
EXPERIMENTAL.

If you want to benefit form this feature, you have to install
JavaScript engine from mozilla.org (SpiderMonkey). You have to do it
even when you have Mozilla browser installed, because the binary
browser installation doesn't include essential header files.

An alternative way to get all neccessary JS files is to download and 
install Charlie application framework (see gingerall.org).

All you need to do on Sablotron side is to run the configure script 
with --enable-javascript option. To use JS engine from Charlie
installation, type: ./configure  --enable-javascript --enable-perlconnect

If you have installed JS libraries into non-standard directories, you 
need to set (and export) CPLUS_INCLUDE_PATH/LIBRARY_PATH to point to
directories where the header files/lib files (e.g. libjs.so) can be found.

The default name for the linked library is 'js' (-ljs switch) - if you
need to override this value, you may set SABLOT_JSLIB environment
variable - the configure script uses -l$(SABLOT_JSLIB) in this case.


2. What is working
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Sablotron supports JavaScript (ECMA) scripting as described in XSTL WD
1.1. with few exceptions:

- DOM functions handling namespaces (with NS in their name) are not
  supported (throw NOT_SUPPORTED exception)

- DOM model is read only (as supported, may be changed later)

- XSLTContext.stringValue is not supported

- Document.getElementsByTagName{NS} are not supported

- Element.getElementsByTagName{NS} are not supported

- DTD definition nodes are not supported


The following summarizes what IS supported:

- exslt:script element support

- XSLTContext object

- DOM2 acces to a processed document

- type mapping between XPath and JavaScript including the XSLT
  external object support

- function-available() function

- element-available() function


3. Sample stylesheet
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<?xml version='1.0'?>
<xsl:stylesheet version='1.0'
		xmlns:xsl='http://www.w3.org/1999/XSL/Transform'
		xmlns:exslt='http://www.exslt.org/functions'
		xmlns:my='http://gingerall.org/sablot/myfunc'
		extension-element-prefixes='exslt'
		exclude-result-prefixes='my'>

  <xsl:output method='xml' indent='yes'/>

  <exslt:script language='javascript' implements-prefix='my'>
  <![CDATA[
    
    function getNodeNames(nodeList)
    {
      ret = '';
      for (i = 0; i < nodeList.length; i++)
      {
        ret += nodeList[i].nodeName + " ";
      }
      return ret;
    }  	  

  ]]>
  </exslt:script>


  <xsl:template match='/'>
    <output>
      <xsl:value-of select='my:getNodeNames(*)'/>
    </output>
  <xsl:template>

</xsl:stylesheet>
