(PHP 4 >= 4.3.0)
xslt_set_object — Sets the object in which to resolve callback functions
$processor
   , object &$obj
   )
   This function allows to use the processor inside
   an object and to resolve all callback functions
   in it.
  
   The callback functions can be declared with
   xslt_set_sax_handlers(),
   xslt_set_scheme_handlers() or
   xslt_set_error_handler() and are assumed to be methods
   of object.
  
   Returns TRUE on success or FALSE on failure.
  
Example #1 Using your own error handler as a method
<?php
class my_xslt_processor {
    var $_xh; // our XSLT processor
    function my_xslt_processor()
    {
        $this->_xh = xslt_create();
        // Make $this object the callback resolver
        xslt_set_object($this->_xh, $this);
        // Let's handle the errors
        xslt_set_error_handler($this->_xh, "my_xslt_error_handler");
    }
    function my_xslt_error_handler($handler, $errno, $level, $info)
    {
        // for now, let's just see the arguments
        var_dump(func_get_args());
    }
}
?>