The DOMDocument::getElementsByTagNameNS() function is an inbuilt function in PHP which is used to search for all elements with given tag name in specified namespace.
Syntax:
DOMNodeList DOMDocument::getElementsByTagNameNS(
string $namespaceURI, string $localName )
Parameters: This function accepts two parameters as mentioned above and described below:
- $namespaceURI: It specifies the namespace URI of the elements to match on and * matches all namespaces.
- $localName : It specifies the local name of the elements to match on and * matches all local names.
Return Value: This function returns a DOMNodeList of all elements with a given local name and a namespace URI.
Below given programs illustrate the DOMDocument::getElementsByTagNameNS() function in PHP:
Program 1: In this example, we will get localname and prefix of elements with a specific namespace.
PHP
<?php// Create an XML$xml = <<<EOD<?xml version="1.0" ?><!-- this is the namespace --><chapter xmlns:xi="my_namespace"><title>Books of the other guy..</title><para> <xi:include> <xi:fallback> </xi:fallback> </xi:include></para></chapter>EOD;$dom = new DOMDocument; // Load the XML string defined above$dom->loadXML($xml); // Use getElementsByTagName to get// the elements from xmlforeach ($dom->getElementsByTagNameNS( 'my_namespace', '*') as $element) { echo '<b>Local name:</b> ', $element->localName, ', <b>Prefix: </b>', $element->prefix, "<br>";}?> |
Output:
Local name: include, Prefix: xi Local name: fallback, Prefix: xi
Program 2: In this example, we will get the number of elements of a certain namespace.
PHP
<?php// Create an XML$xml = <<<EOD<?xml version="1.0" ?><!-- this is the namespace --><chapter xmlns:xi="my_namespace"><title>Books of the other guy..</title><para> <xi:include> <!-- 1st --> <xi:fallback> <!-- 2nd --> </xi:fallback> </xi:include> <xi:include> <!-- 3rd --> <xi:fallback> <!-- 4th --> </xi:fallback> </xi:include></para></chapter>EOD; $dom = new DOMDocument(); // Load the XML string defined above$dom->loadXML($xml); // It will count all occurrence of// xi inside my_namespace$elements = $dom->getElementsByTagNameNS( 'my_namespace', '*');print_r($elements->length);?> |
Output:
4
Reference: https://www.php.net/manual/en/domdocument.getelementsbytagnamens.php
