CODEWITHSUNDEEP
phpxml
mikl
mikl

Reputation: 1007

Canonicalization (c14n) of XML code using PHP class method

I found in PHP documentation a method from the DOMNode class, defined as DOMNode::C14N (https://www.php.net/manual/en/domnode.c14n.php). Sadly i've had a hard time finding complete examples about its usage, and I have tryed some code with no success... probably due to my null experience using the PHP native classes.

<?php
$Document = '<Document>... (more XML code to canonicalize)</Document>';

$xml = new C14N();
$xml = $Document->C14N();

When executing i get:

Fatal error: Class 'C14N' not found in C:\wamp\www\...

I have researched and the class DOMNode is included in the DOM extension which is suposed to come installed and enabled by default, plus c14n is not a class but a method.

I have PHP 5.3.13.

Thanks in advance.

Upvotes: 1

Views: 6502

Answers (1)

hakre
hakre

Reputation: 198109

To help you reading the PHP Manual here:

DOMNode::C14N

This means for the class DOMNode there is a method named C14N.

So where to find such a DOMNode, so you can call that method on?

Well, DOMDocument for example is a DOMNode, see the following manual page: https://www.php.net/manual/en/class.domdocument.php it write that

DOMDocument extends DOMNode {

An extends stands for is a, so DOMDocument is a DOMNode. Scrolling down on that page will already give you some general example code on how to create such an object, you then only need to call the method:

// "Create" the document.
$xml = new DOMDocument( "1.0", "ISO-8859-15" );
$xml->loadXML('<Document>... (more XML code to canonicalize)</Document>');
echo $xml->C14N();

Hope this helps you with your orientation.

Example (Online-demo):

<?php
// "Create" the document.
$xml = new DOMDocument( "1.0", "ISO-8859-15" );
$xml->loadXML('<Document b="c"    

f="e"  a="j">...

<!-- stupid whitespace example -->

   mother told me to        go shopping
   
</Document>');

echo $xml->C14N();

Program Output

<Document a="j" b="c" f="e">...



   mother told me to        go shopping
   
</Document>

As this example shows, the attributes are sorted and the comment has been removed.

Upvotes: 4

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