Apply transforms to XML attribute containing escaped HTML

Question

I have some XML that looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<root>
    <issue xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <comment text="&lt;div class=&quot;wiki text&quot;&gt;&lt;h4&gt;Tom Fenech&lt;/h4&gt;Here is a comment&lt;/div&gt;&#10;"/>
    </issue>
</root>

As you can see, the text attribute in the comment node contains escaped HTML. I would like to get the contents of the attribute as XHTML, which I currently do this inside a template using:

<xsl:value-of select="@text" disable-output-escaping="yes" />

That gets me the HTML in the final output:

<div class="wiki text"><h4>Tom Fenech</h4>Here is a comment</div>

But I want to be able to extract the contents of the <h4> tag to use elsewhere. In general, it would be nice to be able to manipulate the contents of this once it has been escaped.

How do I apply further templates to the output of the <xsl:value-of />?

I am currently using the PHP built-in XSLT processor, which supports XSLT version 1.0, although I would be willing to consider using an alternative processor if features from newer versions make this possible.

Which XSLT processor do you use or can you use? Saxon 9.6 HE edition is an XSLT 3.0 processor that would allow you to use `` or perhaps better ``. See http://www.w3.org/TR/xpath-functions-30/#func-parse-xml. If you want to make use of `value-of` and `disable-output-escaping` then you always need two stylesheets, the first which outputs the attribute value using `disable-output-escaping` and the second which consumes the result of the first. — Martin Honnen, Nov 19 '14 at 15:49
@Martin I'm using the XSLT processor that comes with PHP (which supports only version 1.0). I've updated the question. I understand that it is possible to use other XSLT processors (such as Saxon) with PHP, so I would still be interested in solutions that used features from more modern versions. — Tom Fenech, Nov 19 '14 at 15:59

score 1 · Answer 1 · edited May 23 '17 at 11:56

1

You cannot apply templates to unparsed (escaped or CDATA) text. See some previous answers that may be relevant to you:

Parsing html with xslt

XSLT: Reading a param that's an xml document passed as a string

how to parse the xml inside CDATA of another xml using xslt?

edited May 23 '17 at 11:56

Community

1
1

answered Nov 19 '14 at 14:53

michael.hor257k

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Thanks for the links - I suspected that this may not be possible in XSLT but was hoping there might be a way round it. – Tom Fenech Nov 21 '14 at 10:26

score 1 · Accepted Answer · edited Nov 19 '14 at 16:39

Here's one way you could do it, by calling into a PHP function from XSLT:

function parseHTMLString($html)
{
    $doc = new DOMDocument();
    $doc->loadHTML($html);
    return $doc;
}

$xml = <<<EOB
<root>
    <issue xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <comment text="&lt;div class=&quot;wiki text&quot;&gt;&lt;h4&gt;Tom Fenech&lt;/h4&gt;Here is a comment&lt;/div&gt;&#10;"/>
    </issue>
</root>
EOB;

$xsl = <<<EOB
<xsl:stylesheet version="1.0"
     xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
     xmlns:php="http://php.net/xsl"
     xsl:extension-element-prefixes="php">
<xsl:output method="html" encoding="utf-8" indent="yes"/>
 <xsl:template match="comment">
   <xsl:apply-templates select="php:functionString('parseHTMLString', @text)//div/h4"/>
 </xsl:template>

 <xsl:template match="div/h4">
   <h2><xsl:apply-templates/></h2>
 </xsl:template>
</xsl:stylesheet>
EOB;

$xmldoc = new DOMDocument();
$xmldoc->loadXML($xml);

$xsldoc = new DOMDocument();
$xsldoc->loadXML($xsl);

$proc = new XSLTProcessor();
$proc->registerPHPFunctions('parseHTMLString');
$proc->importStyleSheet($xsldoc);
echo $proc->transformToXML($xmldoc);

Impressive, thanks! There were a couple of changes to make it work - I had to add `xsl:extension-element-prefixes="php"` to the opening tag and change the syntax of the function call. — Tom Fenech, Nov 19 '14 at 16:41

Apply transforms to XML attribute containing escaped HTML

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