shlink/module/Common/src/Util/ResponseUtilsTrait.php

<?php
namespace Shlinkio\Shlink\Common\Util;

use Zend\Diactoros\Response;
use Zend\Diactoros\Stream;
use Zend\Stdlib\ArrayUtils;

trait ResponseUtilsTrait
{
    protected function generateDownloadFileResponse($filePath)
    {
        return $this->generateBinaryResponse($filePath, [
            'Content-Disposition' => 'attachment; filename=' . basename($filePath),
            'Content-Transfer-Encoding' => 'Binary',
            'Content-Description' => 'File Transfer',
            'Pragma' => 'public',
            'Expires' => '0',
            'Cache-Control' => 'must-revalidate',
        ]);
    }

    protected function generateImageResponse($imagePath)
    {
        return $this->generateBinaryResponse($imagePath);
    }

    protected function generateBinaryResponse($path, $extraHeaders = [])
    {
        $body = new Stream($path);
        return new Response($body, 200, ArrayUtils::merge([
            'Content-Type' => (new \finfo(FILEINFO_MIME))->file($path),
            'Content-Length' => (string) $body->getSize(),
        ], $extraHeaders));
    }
}