Helper sitemap index xml

SiteMapIndexXML.php

<?php

/**
 * SiteMapIndexXML
 *
 * A simple helper to make simple sitemap.xml of index
 *
 * Usage:
 *   $sitemap = new SiteMapIndexXML();
 *   $sitemap->addSiteMap('http://example.org/sitemap-products.xml');
 *   $sitemap->saveXML() // returns the string xml
 *
 * @author Jeremy Perret <jerem@devster.org> 
 */
class SiteMapIndexXML extends \DOMDocument
{
    public $root;
    
    public function __construct($charset = 'UTF-8')
    {
        parent::__construct('1.0', $charset);
        
        $this->root = $this->appendChild($this->createElement('sitemapindex'));
        $xmlns = $this->createAttribute('xmlns');
        $xmlns->value = 'http://www.sitemaps.org/schemas/sitemap/0.9';
        $this->root->appendChild($xmlns);
    }
    
    public function addSiteMap($url)
    {
        $urlNode = $this->createElement('sitemap');
        $this->root->appendChild($urlNode);

        $urlNode->appendChild($this->_createTextNode('loc', $url));
    }
    
    protected function _createTextNode($name, $value)
    {
        $el = $this->createElement($name);
        $el->appendChild($this->createTextNode($value));
        
        return $el;
    }
}