domdocument.getelementbyid(3) php man page | unix.com

DOMDOCUMENT.GETELEMENTBYID(3)						 1					     DOMDOCUMENT.GETELEMENTBYID(3)

DOMDocument::getElementById - Searches for an element with a certain id

SYNOPSIS
       public DOMElement DOMDocument::getElementById (string  $elementId)

DESCRIPTION
	This function is similar to "DOMDocument::getElementsByTagName" but searches for an element with a given id.

	For  this  function  to  work,	you will need either to set some ID attributes with "DOMElement::setIdAttribute" or a DTD which defines an
       attribute to be of type ID. In the later case, you will need to validate your document with "DOMDocument::validate" or  DOMDocument::$vali-
       dateOnParse before using this function.

PARAMETERS
	      o $elementId
		- The unique id value for an element.

RETURN VALUES
	Returns the DOMElement or NULL if the element is not found.

EXAMPLES
       Example #1

	      DOMDocument::getElementById() Example

	      The following examples use book.xml which contains the following:

	      <?xml version="1.0" encoding="UTF-8"?>
	      <!DOCTYPE books [
		<!ELEMENT books   (book+)>
		<!ELEMENT book	  (title, author+, xhtml:blurb?)>
		<!ELEMENT title   (#PCDATA)>
		<!ELEMENT blurb   (#PCDATA)>
		<!ELEMENT author  (#PCDATA)>
		<!ATTLIST books   xmlns        CDATA  #IMPLIED>
		<!ATTLIST books   xmlns:xhtml  CDATA  #IMPLIED>
		<!ATTLIST book	  id	       ID     #IMPLIED>
		<!ATTLIST author  email        CDATA  #IMPLIED>
	      ]>
	      <?xml-stylesheet type="text/xsl" href="style.xsl"?>
	      <books xmlns="http://books.php/" xmlns:xhtml="http://www.w3.org/1999/xhtml">
		<book id="php-basics">
		  <title>PHP Basics</title>
		  <author email="jim.smith@basics.php">Jim Smith</author>
		  <author email="jane.smith@basics.php">Jane Smith</author>
		  <xhtml:blurb><![CDATA[
	      <p><em>PHP Basics</em> provides an introduction to PHP.</p>
	      ]]></xhtml:blurb>
		</book>
		<book id="php-advanced">
		  <title>PHP Advanced Programming</title>
		  <author email="jon.doe@advanced.php">Jon Doe</author>
		</book>
	      </books>

	      <?php

	      $doc = new DomDocument;

	      // We need to validate our document before refering to the id
	      $doc->validateOnParse = true;
	      $doc->Load('book.xml');

	      echo "The element whose id is 'php-basics' is: " . $doc->getElementById('php-basics')->tagName . "
";

	      ?>

	      The above example will output:

	      The element whose id is 'php-basics' is: book

SEE ALSO
       DOMDocument::getElementsByTagName.

PHP Documentation Group 											     DOMDOCUMENT.GETELEMENTBYID(3)