Set the scheme handlers for the XSLT processor

xslt_set_scheme_handler
xslt_setopt
XSLT (PHP4) Functions
PHP Manual

# xslt_set_scheme_handlers

(PHP 4 >= 4.0.6)

xslt_set_scheme_handlers — Set the scheme handlers for the XSLT processor

### Description

void xslt_set_scheme_handlers ( resource `$xh` , array `$handlers` )

Registers the scheme handlers (XPath handlers) for the document.

### Parameters

`xh`

  The XSLT processor link identifier, created with xslt_create().

`handlers`

  An array with the following keys: "get_all", "open", "get", "put", and "close".

  Every entry must be a function name or an array in the following format: array($obj, "method").

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

  Each of the individual scheme handler functions called are in the formats below:

      string   get_all(resource processor, string scheme, string rest)
      resource open(resource processor, string scheme, string rest)
      int      get(resource processor, resource fp, string &data)
      int      put(resource processor, resource fp, string data)
      void     close(resource processor, resource fp)

### Return Values

No value is returned.

### Examples

Example #1 xslt_set_scheme_handlers() example

For example, here is an implementation of the "file_exists()" PHP function.

`<?php
// Definition of the handler
function mySchemeHandler($processor, $scheme, $rest)
{
$rest = substr($rest,1); // to remove the first / automatically added by the engine
if ($scheme == 'file_exists') {
// result is embedded in a small xml string
return '<?xml version="1.0" encoding="UTF-8"?><root>' . (file_exists($rest) ? 'true' : 'false') . '</root>';
}
}
$SchemeHandlerArray = array('get_all' => 'mySchemeHandler');
// Start the engine
$params = array();
$xh = xslt_create();
xslt_set_scheme_handlers($xh, $SchemeHandlerArray);
$result = xslt_process($xh, "myFile.xml", "myFile.xsl", NULL, array(), $params);
xslt_free($xh);
echo $result;
?>`

Then, inside the stylesheet, you can test whether a certain file exists with:

    <xsl:if test="document('file_exists:anotherXMLfile.xml')/root='true'">
     <!-- The file exist -->
    </xsl:if>

### See Also

- xslt_set_scheme_handler() - Set Scheme handlers for a XSLT processor

xslt_set_scheme_handler
xslt_setopt
XSLT (PHP4) Functions
PHP Manual