RelatedPart.php

<?php


/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace Symfony\Component\Mime\Part\Multipart;

use Symfony\Component\Mime\Part\AbstractMultipartPart;
use Symfony\Component\Mime\Part\AbstractPart;

/**
 * @author Fabien Potencier <fabien@symfony.com>
 */
final class RelatedPart extends AbstractMultipartPart {
    public function __construct(AbstractPart $mainPart, AbstractPart $part, AbstractPart ...$parts) {
        $this->prepareParts($part, ...$parts);
        parent::__construct($part, ...$parts);
    }
    public function getParts() : array {
        return array_merge([
            $this->mainPart,
        ], parent::getParts());
    }
    public function getMediaSubtype() : string {
        return 'related';
    }
    private function generateContentId() : string {
        return bin2hex(random_bytes(16)) . '@symfony';
    }
    private function prepareParts(AbstractPart ...$parts) : void {
        foreach ($parts as $part) {
            if (!$part->getHeaders()
                ->has('Content-ID')) {
                $part->getHeaders()
                    ->setHeaderBody('Id', 'Content-ID', $this->generateContentId());
            }
        }
    }

}