Developer
<?php
namespace PhpOffice\PhpSpreadsheet\Helper;
use PhpOffice\PhpSpreadsheet\Exception;
class Downloader
{
protected string $filepath;
protected string $filename;
protected string $filetype;
protected const CONTENT_TYPES = [
'xlsx' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
'xls' => 'application/vnd.ms-excel',
'ods' => 'application/vnd.oasis.opendocument.spreadsheet',
'csv' => 'text/csv',
'html' => 'text/html',
'pdf' => 'application/pdf',
];
public function __construct(string $folder, string $filename, ?string $filetype = null)
{
if ((is_dir($folder) === false) || (is_readable($folder) === false)) {
throw new Exception("Folder {$folder} is not accessable");
}
$filepath = "{$folder}/{$filename}";
$this->filepath = (string) realpath($filepath);
$this->filename = basename($filepath);
if ((file_exists($this->filepath) === false) || (is_readable($this->filepath) === false)) {
throw new Exception("{$this->filename} not found, or cannot be read");
}
$filetype ??= pathinfo($filename, PATHINFO_EXTENSION);
if (array_key_exists(strtolower($filetype), self::CONTENT_TYPES) === false) {
throw new Exception("Invalid filetype: {$filetype} cannot be downloaded");
}
$this->filetype = strtolower($filetype);
}
public function download(): void
{
$this->headers();
readfile($this->filepath);
}
public function headers(): void
{
ob_clean();
$this->contentType();
$this->contentDisposition();
$this->cacheHeaders();
$this->fileSize();
flush();
}
protected function contentType(): void
{
header('Content-Type: ' . self::CONTENT_TYPES[$this->filetype]);
}
protected function contentDisposition(): void
{
header('Content-Disposition: attachment;filename="' . $this->filename . '"');
}
protected function cacheHeaders(): void
{
header('Cache-Control: max-age=0');
// If you're serving to IE 9, then the following may be needed
header('Cache-Control: max-age=1');
// If you're serving to IE over SSL, then the following may be needed
header('Expires: Mon, 26 Jul 1997 05:00:00 GMT'); // Date in the past
header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT'); // always modified
header('Cache-Control: cache, must-revalidate'); // HTTP/1.1
header('Pragma: public'); // HTTP/1.0
}
protected function fileSize(): void
{
header('Content-Length: ' . filesize($this->filepath));
}
}
Developer
To ensure a smooth integration process and optimal performance, follow these best practices: