<form method="POST">
    <h3>Editing: ManifestElement.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php declare(strict_types = 1);
/*
 * This file is part of PharIo\Manifest.
 *
 * Copyright (c) Arne Blankerts &lt;arne@blankerts.de&gt;, Sebastian Heuer &lt;sebastian@phpeople.de&gt;, Sebastian Bergmann &lt;sebastian@phpunit.de&gt; and contributors
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 *
 */
namespace PharIo\Manifest;

use DOMElement;
use DOMNodeList;
use function sprintf;

class ManifestElement {
    public const XMLNS = 'https://phar.io/xml/manifest/1.0';

    /** @var DOMElement */
    private $element;

    public function __construct(DOMElement $element) {
        $this-&gt;element = $element;
    }

    protected function getAttributeValue(string $name): string {
        if (!$this-&gt;element-&gt;hasAttribute($name)) {
            throw new ManifestElementException(
                sprintf(
                    'Attribute %s not set on element %s',
                    $name,
                    $this-&gt;element-&gt;localName
                )
            );
        }

        return $this-&gt;element-&gt;getAttribute($name);
    }

    protected function hasAttribute(string $name): bool {
        return $this-&gt;element-&gt;hasAttribute($name);
    }

    protected function getChildByName(string $elementName): DOMElement {
        $element = $this-&gt;element-&gt;getElementsByTagNameNS(self::XMLNS, $elementName)-&gt;item(0);

        if (!$element instanceof DOMElement) {
            throw new ManifestElementException(
                sprintf('Element %s missing', $elementName)
            );
        }

        return $element;
    }

    protected function getChildrenByName(string $elementName): DOMNodeList {
        $elementList = $this-&gt;element-&gt;getElementsByTagNameNS(self::XMLNS, $elementName);

        if ($elementList-&gt;length === 0) {
            throw new ManifestElementException(
                sprintf('Element(s) %s missing', $elementName)
            );
        }

        return $elementList;
    }

    protected function hasChild(string $elementName): bool {
        return $this-&gt;element-&gt;getElementsByTagNameNS(self::XMLNS, $elementName)-&gt;length !== 0;
    }
}
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