PHP | DOMDocument relaxNGValidate() Function

The DOMDocument::relaxNGValidate() function is an inbuilt function in PHP which is used to performs relaxNG validation on the document. The relaxNG is an alternative to DDT and defines a structure which needs to be followed by the XML document.

Syntax:

bool DOMDocument::relaxNGValidate( string $filename )

Parameters: This function accepts a single parameter $filename which holds the RNG file.

Return Value: This function returns TRUE on success or FALSE on failure.

Below given programs illustrate the DOMDocument::relaxNGValidate() function in PHP:

Program 1:

• File name: rule.rng

  
  

  
  
  

  <element name="college"    xmlns="http://relaxng.org/ns/structure/1.0">   <zeroOrMore>     <element name="rollno">       <element name="name">         <text/>       </element>       <element name="subject">         <text/>       </element>     </element>   </zeroOrMore> </element>

• File name: index.php

  
  

  
  
  

  <?php    // Create a new DOMDocument $doc = new DOMDocument;    // Load the XML $doc->loadXML("<?xml version=\"1.0\"?> <college>   <rollno>     <name>John Smith</name>     <subject>Web</subject>   </rollno>   <rollno>     <name>John Doe</name>     <subject>CSE</subject>   </rollno> </college>");    // Check if XML follows the relaxNG rule if ($doc->relaxNGValidate('rule.rng')) {     echo "This document is valid!\n"; } ?>

• Output:

  This document is valid!

Program 2:

• File name: rule.rng

  
  

  
  
  

  <element name="company"    xmlns="http://relaxng.org/ns/structure/1.0">   <zeroOrMore>     <element name="employee">       <element name="name">         <text/>       </element>       <element name="salary">         <text/>       </element>     </element>   </zeroOrMore> </element>

• File name: index.php

  
  

  
  
  

  <?php    // Create a new DOMDocument $doc = new DOMDocument;    // Load the XML $doc->loadXML("<?xml version=\"1.0\"?> <company>   <employee>     <name>John Smith</name>     <salary>Web</salary>   </employee>   <employee>     <!-- Do not add salary to voilate rule -->     <name>John Doe</name>   </employee> </company>");    // Check if XML doesn't follows the relaxNG rule if (!$doc->relaxNGValidate('rule.rng')) {     echo "This document is not valid!\n"; } ?>

• Output:

  This document is not valid!

Reference: https://www.php.net/manual/en/domdocument.relaxngvalidate.php