XObjects.php

<?php
/**
 * XObjects - XPath based Objects for SimpleXMLElement
 *
 * @author hakre <http://hakre.wordpress.com/credits/>
 */

/**
 * Class XListIterator
 */
class XListIterator extends ArrayIterator
{
    private $prototype;

    public function __construct(SimpleXMLElement $doc, XPrototype $prototype)
    {
        parent::__construct($prototype->createNodeList($doc));
        $this->prototype = $prototype;
    }

    public function current()
    {
        return $this->prototype->cast(parent::current());
    }
}

/**
 * Class XList
 */
class XList implements IteratorAggregate
{
    private $doc;
    private $proptype;

    public static function createSimpleXMLelment($mixed)
    {
        if ($mixed instanceof SimpleXMLElement) {
            return $mixed;
        }

        if (!(is_string($mixed) && strlen($mixed))) {
            return NULL;
        }

        if ($mixed[0] === '<') {
            return simplexml_load_string($mixed);
        }

        return simplexml_load_file($mixed);
    }

    public function __construct($doc, XPrototype $prototype)
    {
        $this->doc      = self::createSimpleXMLelment($doc);
        $this->proptype = $prototype;
    }

    public function getIterator()
    {
        return new XListIterator(
            $this->doc,
            $this->proptype
        );
    }
}

/**
 * Class XPrototype
 */
class XPrototype
{
    private $anchor;
    /**
     * @var array|string[]
     */
    private $props;
    /**
     * @var array|string[]
     */
    private $prefixes;

    function __construct($anchor, array $props, array $prefixes = array())
    {
        $this->anchor   = $anchor;
        $this->props    = $props;
        $this->prefixes = $prefixes;
    }

    private function registerPrefixes(SimpleXMLElement $node)
    {
        $prefixes = $this->prefixes;
        $prefixes += $node->getNamespaces(TRUE);
        foreach ($prefixes as $prefix => $ns) {
            $node->registerXPathNamespace($prefix, $ns);
        }
    }

    public function createNodeList(SimpleXMLElement $from)
    {
        $this->registerPrefixes($from);
        return $from->xpath($this->anchor);
    }

    public function cast(SimpleXMLElement $node)
    {
        $object = new stdClass();
        foreach ($this->props as $name => $xprop) {
            $this->registerPrefixes($node);
            $value         = $node->xpath($xprop);
            $object->$name = $value ? (string)$value[0] : NULL;
        }
        return $object;
    }
}