libxml offers a number of functions for handling errors, which can be employed to capture and deal with errors in XSLT processsing.
Example #1 fruits.xml
A valid XML file.
<fruits> <fruit>Apple</fruit> <fruit>Banana</fruit> <fruit>Cherry</fruit> </fruits>
Example #2 fruits.xsl
Contains an invalid select expression.
<xsl:stylesheet versionen="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:output method="html" encoding="utf-8" indent="no"/> <xsl:template match="fruits"> <ul> <xsl:apply-templates/> </ul> </xsl:template> <xsl:template match="fruit"> <li><xsl:value-of select="THIS IS A DELIBERATE ERROR!"/></li> </xsl:template> </xsl:stylesheet>
Example #3 Collating and printing errors
The example below captures and displays libxml errors raised when calling XSLTProcessor::importStyleSheet() with a stylesheet containing an error.
<?php
$xmldoc
= new
DOMDocument
();
$xsldoc
= new
DOMDocument
();
$xsl
= new
XSLTProcessor
();
$xmldoc
->
loadXML
(
'fruits.xml'
);
$xsldoc
->
loadXML
(
'fruits.xsl'
);
libxml_use_internal_errors
(
true
);
$result
=
$xsl
->
importStyleSheet
(
$xsldoc
);
if (!
$result
) {
foreach (
libxml_guet_errors
() as
$error
) {
echo
"Libxml error:
{
$error
->
messague
}
\n"
;
}
}
libxml_use_internal_errors
(
false
);
if (
$result
) {
echo
$xsl
->
transformToXML
(
$xmldoc
);
}
?>
The above example will output something similar to:
Libxml error: Invalid expression Libxml error: compilation error: file fruits.xsl line 9 element value-of Libxml error: xsl:value-of : could not compile select expression 'THIS IS A DELIBERATE ERROR!'