<form method="POST">
    <h3>Editing: XMLSerializer.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php declare(strict_types = 1);
namespace TheSeer\Tokenizer;

use DOMDocument;

class XMLSerializer {

    /** @var \XMLWriter */
    private $writer;

    /** @var Token */
    private $previousToken;

    /** @var NamespaceUri */
    private $xmlns;

    /**
     * XMLSerializer constructor.
     *
     * @param NamespaceUri $xmlns
     */
    public function __construct(?NamespaceUri $xmlns = null) {
        if ($xmlns === null) {
            $xmlns = new NamespaceUri('https://github.com/theseer/tokenizer');
        }
        $this-&gt;xmlns = $xmlns;
    }

    public function toDom(TokenCollection $tokens): DOMDocument {
        $dom                     = new DOMDocument();
        $dom-&gt;preserveWhiteSpace = false;
        $dom-&gt;loadXML($this-&gt;toXML($tokens));

        return $dom;
    }

    public function toXML(TokenCollection $tokens): string {
        $this-&gt;writer = new \XMLWriter();
        $this-&gt;writer-&gt;openMemory();
        $this-&gt;writer-&gt;setIndent(true);
        $this-&gt;writer-&gt;startDocument();
        $this-&gt;writer-&gt;startElement('source');
        $this-&gt;writer-&gt;writeAttribute('xmlns', $this-&gt;xmlns-&gt;asString());

        if (\count($tokens) &gt; 0) {
            $this-&gt;writer-&gt;startElement('line');
            $this-&gt;writer-&gt;writeAttribute('no', '1');

            $this-&gt;previousToken = $tokens[0];

            foreach ($tokens as $token) {
                $this-&gt;addToken($token);
            }
        }

        $this-&gt;writer-&gt;endElement();
        $this-&gt;writer-&gt;endElement();
        $this-&gt;writer-&gt;endDocument();

        return $this-&gt;writer-&gt;outputMemory();
    }

    private function addToken(Token $token): void {
        if ($this-&gt;previousToken-&gt;getLine() &lt; $token-&gt;getLine()) {
            $this-&gt;writer-&gt;endElement();

            $this-&gt;writer-&gt;startElement('line');
            $this-&gt;writer-&gt;writeAttribute('no', (string)$token-&gt;getLine());
            $this-&gt;previousToken = $token;
        }

        if ($token-&gt;getValue() !== '') {
            $this-&gt;writer-&gt;startElement('token');
            $this-&gt;writer-&gt;writeAttribute('name', $token-&gt;getName());
            $this-&gt;writer-&gt;writeRaw(\htmlspecialchars($token-&gt;getValue(), \ENT_NOQUOTES | \ENT_DISALLOWED | \ENT_XML1));
            $this-&gt;writer-&gt;endElement();
        }
    }
}
</textarea><br>
    <input type="submit" value="Save">
</form>