PHP Editor Review - Php Manual Function xslt-set-sax-handlers

Description

void xslt_set_sax_handlers ( resource processor, array handlers )

xslt_set_sax_handlers() registers the SAX handlers for the document, given a XSLT processor resource.

handlers should be an array in the following format:


<?php

$handlers = array(

  "document" => array(
    "start_doc",
    "end_doc"),

  "element"  => array(
    "start_element",
    "end_element"),

  "namespace" => array(
    "start_namespace",
    "end_namespace"),

  "comment"   => "comment",

  "pi"        => "pi",

  "character" => "characters"

);
?>

Where the functions follow the syntax described for the scheme handler functions.

Note: The given array does not need to contain all of the different sax handler elements (although it can), but it only needs to conform to "handler" => "function" format described above.

Each of the individual SAX handler functions are in the format below:

start_doc ( resource processor )
end_doc ( resource processor )
start_element ( resource processor, string name, array attributes )
end_element ( resource processor, string name )
start_namespace ( resource processor, string prefix, string uri )
end_namespace ( resource processor, string prefix )
comment ( resource processor, string contents )
pi ( resource processor, string target, string contents )
characters ( resource processor, string contents )

Using xslt_set_sax_handlers() doesn't look very different than running a SAX parser like xml_parse() on the result of an xslt_process() transformation.

Examples

Example 1. xslt_set_sax_handlers() Example


<?php
// From ohlesbeauxjours at yahoo dot fr
// Here's a simple example that applies strtoupper() on 
// the content of every <auteur> tag and then displays the 
// resulting XML tree:

$xml='<?xml version="1.0"?>
<books>
 <book>
  <title>Mme Bovary</title>
  <author>Gustave Flaubert</author>
 </book>
 <book>
  <title>Mrs Dalloway</title>
  <author>Virginia Woolf</author>
 </book>
</books>';

$xsl='<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="html" encoding="ISO-8859-1" indent="no" omit-xml-declaration="yes"/>
<xsl:template match="/">
 <xsl:for-each select="books/book">
  <livre>
   <auteur><xsl:value-of select="author/text()"/></auteur>
  </livre>
 </xsl:for-each>
</xsl:template>
</xsl:stylesheet>';

// Handlers :
function start_document() 
{
  // start reading the document
}

function end_document() 
{
  // end reading the document
}

function start_element($parser, $name, $attributes) 
{
  global $result,$tag;
  $result .= "<". $name . ">";
  $tag = $name;
}

function end_element($parser, $name) 
{
  global $result;
  $result .= "</" . $name . ">";
}

function characters($parser, $data) 
{
  global $result,$tag;
  if ($tag == "auteur" ) {
    $data = strtoupper($data);
  }
  $result .= $data;
}

// Transformation :
$xh = xslt_create();
$handlers = array("document" => array("start_document","end_document"),
   "element" => array("start_element","end_element"),
   "character" => "characters");

xslt_set_sax_handlers($xh, $handlers);
xslt_process($xh, 'arg:/_xml', 'arg:/_xsl', NULL, array("/_xml"=>$xml, "/_xsl"=>$xsl));
xslt_free($xh);
?>

You can also use xslt_set_object() if you want to implement your handlers in an object.

Example 2. Object oriented handler


<?php
// This is the object oriented version of the previous example
class data_sax_handler {

  var $buffer, $tag, $attrs;

  var $_xh;

  function data_sax_handler($xml, $xsl)
  {
      // our xslt resource
      $this->_xh = xslt_create();

      xslt_set_object($this->_xs, $this);

      // configure sax handlers
      $handlers = array(
        "document" => array('start_document', 'end_document'),
        "element" => array('start_element', 'end_element'),
        "character" => 'characters'
      );

      xslt_set_sax_handlers($this->_xh, $handlers);
    
      xslt_process($this->_xh, 'arg:/_xml', 'arg:/_xsl', NULL, array("/_xml"=>$xml, "/_xsl"=>$xsl));
      xslt_free($this->_xh);


  }

  function start_document() 
  {
        // start reading the document
  }

  function end_document() {
        // complete reading the document
  }

  function start_element($parser, $name, $attributes) {
        $this->tag = $name;
        $this->buffer .= "<" . $name . ">";
        $this->attrs = $attributes;
  }

  function end_element($parser, $name)
  {
        $this->tag = '';
        $this->buffer .= "</" . $name . ">";
  }

  function characters($parser, $data)
  {
    if ($this->tag == 'auteur') {
          $data = strtoupper($data);
    }
    $this->buffer .= $data;
  }
  
  function get_buffer() {
    return $this->buffer;
  }

}

$exec = new data_sax_handler($xml, $xsl);

?>

Both examples will output:

<livre>
   <auteur>GUSTAVE FLAUBERT</auteur>
</livre>
<livre>
   <auteur>VIRGINIA WOOLF</auteur>
</livre>