PHP | XMLReader getAttributeNs() Function

The XMLReader::getAttributeNs() function is an inbuilt function in PHP which is used to get the value of an attribute by name and namespace URI or an empty string if attribute does not exist or not positioned on an element node.

Syntax:

string XMLReader::getAttributeNs( string $localName, 
                               string $namespaceURI )

Parameters: This function accept two parameters as mentioned above and described below:

• $localName: It specifies the local name.
• $namespaceURI: It specifies the namespace URI.

Return Value: This function returns the value of attribute on success or empty string on failure.

Below examples illustrate the XMLReader::getAttributeNs() function in PHP:

Example 1:

• data.xml

  <?xml version="1.0" encoding="utf-8"?>
  <div xmlns:x="geeksforgeeks">
      <x:h1 x:attrib="value">
        Namespaced Text
      </x:h1>
  </div>
• index.php

  <?php
  
  // Create a new XMLReader instance
  $XMLReader = new XMLReader();
  
  // Load the XML file
  $XMLReader->open('data.xml');
  
  // Move to next node three times
  $XMLReader->read();
  $XMLReader->read();
  $XMLReader->read();
  
  // Get the value of attribute but
  // give a wrong namespace here
  $value = $XMLReader->getAttributeNs(
      "attrib", "wrong_namespace");
  
  // Output the value to browser
  echo $value . "<br>";
  
  ?>
• Output:

   // Empty string because namespace name doesn't match

Example 2:

• data.xml

  <?xml version="1.0" encoding="utf-8"?>
  <div xmlns:x="my_namespace">
      <x:h1 x:attrib="value">
        Namespaced Text
      </x:h1>
  </div>
• index.php

  <?php
  
  // Create a new XMLReader instance
  $XMLReader = new XMLReader();
  
  // Load the XML file
  $XMLReader->open('data.xml');
  
  // Iterate through the XML
  while ($XMLReader->read()) {
      if ($XMLReader->nodeType == XMLREADER::ELEMENT) {
  
          // Get the value of attribute with name "attrib"
          // and namespace "my_namespace"
          $value = $XMLReader->
                 getAttributeNs("attrib", "my_namespace");
  
          // Output the value to browser
          echo $value . "<br>";
      }
  }
  ?>
• Output:

  value

Reference: https://www.php.net/manual/en/xmlreader.getattributens.php