The xslt_process() function is the crux of the new
XSLT extension. It allows you to perform an XSLT transformation using
almost any type of input source - the containers. This is accomplished
through the use of argument buffers -- a concept taken from the Sablotron
XSLT processor (currently the only XSLT processor this extension supports).
The input containers default to a filename 'containing' the document to be
processed. The result container defaults to a filename for the transformed
document. If the result container is not specified - i.e.
NULL - than the result is returned.
Внимание
This function has changed its arguments, since version 4.0.6. Do NOT
provide the actual XML or XSL content as 2nd and 3rd argument, as this
will create a segmentation fault, in Sablotron versions up to and
including 0.95.
Containers can also be set via the $arguments
array (see below).
The simplest type of transformation with the
xslt_process() function is the transformation of an
XML file with an XSLT file, placing the result in a third file containing
the new XML (or HTML) document. Doing this with sablotron is really
quite easy...
Пример 1. Using the xslt_process() to transform an XML
file and a XSL file to a new XML file
<?php
// Allocate a new XSLT processor $xh = xslt_create();
// Process the document if (xslt_process($xh, 'sample.xml', 'sample.xsl', 'result.xml')) { echo "SUCCESS, sample.xml was transformed by sample.xsl into result.xml"; echo ", result.xml has the following contents\n<br />\n"; echo "<pre>\n"; readfile('result.xml'); echo "</pre>\n"; } else { echo "Sorry, sample.xml could not be transformed by sample.xsl into"; echo " result.xml the reason is that " . xslt_error($xh) . " and the "; echo "error code is " . xslt_errno($xh); }
xslt_free($xh);
?>
While this functionality is great, many times, especially in a web environment, you want to
be able to print out your results directly. Therefore, if you omit the third argument to
the xslt_process() function (or provide a NULL value for the argument), it
will automatically return the value of the XSLT transformation, instead of writing it to a
file...
Пример 2. Using the xslt_process() to transform an XML file and a XSL file
to a variable containing the resulting XML data
<?php
// Allocate a new XSLT processor $xh = xslt_create();
// Process the document, returning the result into the $result variable $result = xslt_process($xh, 'sample.xml', 'sample.xsl'); if ($result) { echo "SUCCESS, sample.xml was transformed by sample.xsl into the \$result"; echo " variable, the \$result variable has the following contents\n<br />\n"; echo "<pre>\n"; echo $result; echo "</pre>\n"; } else { echo "Sorry, sample.xml could not be transformed by sample.xsl into"; echo " the \$result variable the reason is that " . xslt_error($xh); echo " and the error code is " . xslt_errno($xh); }
xslt_free($xh);
?>
The above two cases are the two simplest cases there are when it comes to XSLT transformation
and I'd dare say that they are the most common cases, however, sometimes you get your XML and
XSLT code from external sources, such as a database or a socket. In these cases you'll have
the XML and/or XSLT data in a variable -- and in production applications the overhead of dumping
these to file may be too much. This is where XSLT's "argument" syntax, comes to the
rescue. Instead of files as the XML and XSLT arguments to the xslt_process()
function, you can specify "argument place holders" which are then substituted by values
given in the arguments array (5th parameter to the xslt_process() function).
The following is an example of processing XML and XSLT into a result variable without the use
of files at all.
Пример 3. Using the xslt_process() to transform a variable containing XML data
and a variable containing XSL data into a variable containing the resulting XML data
<?php // $xml and $xsl contain the XML and XSL data
// Allocate a new XSLT processor $xh = xslt_create();
// Process the document $result = xslt_process($xh, 'arg:/_xml', 'arg:/_xsl', NULL, $arguments); if ($result) { echo "SUCCESS, sample.xml was transformed by sample.xsl into the \$result"; echo " variable, the \$result variable has the following contents\n<br />\n"; echo "<pre>\n"; echo $result; echo "</pre>\n"; } else { echo "Sorry, sample.xml could not be transformed by sample.xsl into"; echo " the \$result variable the reason is that " . xslt_error($xh); echo " and the error code is " . xslt_errno($xh); } xslt_free($xh); ?>
Finally, the last argument to the xslt_process()
function represents an array for any top-level parameters that you want to
pass to the XSLT document. These parameters can then be accessed within
your XSL files using the <xsl:param name="parameter_name">
instruction. The parameters must be UTF-8 encoded and their values will be
interpreted as strings by the Sablotron processor.
In other words - you cannot pass node-sets as parameters to the XSLT document.
Пример 4. Passing PHP variables to XSL files
<?php
// XML string $xml = '<?xml version="1.0"?> <para> change me </para>';