How can I set custom HTTP Headers

[apotek]

Hi, for a variety of reasons, I am still (stuck) on version 2.4. I wanted to set a custom Cache-Control header, since there is no method for setting such a header. I looked at the Archive class (through which I can set options) and there is a method on it called setHttpHeaderCallback(), which seems to accept a callable. When I look at the class docs for the 2.4 version of the Archive class, I see the method documented, but there is no documentation of what should be returned by my callable.

I tried this:

$zip_options = new ArchiveOptions(); // Imported as ArchiveOptions for legibility
...
...
...
$zip_options->setHttpHeaderCallback([$this, 'zipHeaders']);

And my zipHeaders() method returned an array like this:

public function zipHeaders() {
  return [
    'header-one: header one value',
    'another-header: value 2',
  ];
}

I also implemented this function returning not an array but a \n delimited string.

In any event, neither of my attempts worked and none of my test headers were returned. I did trace it with x-debug and the callback was called (five times, which was interesting), but the headers were missing from the response.

What kind of return value should be returned from the callable?

Thank you.

ps., If I am completely missing the boat and there is another way to set a Cache-Control:... header, I am all ears

[maennchen]

@apotek The header callback is used to actually set the header. Its arguments are the header name and the value. No return is expected.

Therefore this is not the functionality you need.

Instead, just disable the headers in ZipStream and set the headers yourself. See:

• ZipStream-PHP/src/ZipStream.php

  Lines 518 to 544 in 620c2aa

  	protected function sendHttpHeaders(): void
  	{
  	// grab content disposition
  	$disposition = $this->opt->getContentDisposition();
  	if ($this->output_name) {
  	// Various different browsers dislike various characters here. Strip them all for safety.
  	$safe_output = trim(str_replace(['"', "'", '\\', ';', "\n", "\r"], '', $this->output_name));
  	// Check if we need to UTF-8 encode the filename
  	$urlencoded = rawurlencode($safe_output);
  	$disposition .= "; filename*=UTF-8''{$urlencoded}";
  	}
  	$headers = [
  	'Content-Type' => $this->opt->getContentType(),
  	'Content-Disposition' => $disposition,
  	'Pragma' => 'public',
  	'Cache-Control' => 'public, must-revalidate',
  	'Content-Transfer-Encoding' => 'binary',
  	];
  	$call = $this->opt->getHttpHeaderCallback();
  	foreach ($headers as $key => $val) {
  	$call("$key: $val");
  	}
  	}

• ZipStream-PHP/src/Option/Archive.php

  Lines 42 to 48 in 620c2aa

  	/**
  	* Boolean indicating whether or not to send
  	* the HTTP headers for this file.
  	*
  	* @var bool
  	*/
  	private $sendHttpHeaders = false;

[apotek]

Thank you for your reply. I am probably misunderstanding, but it seems that the instructions are then to:

foreach ($headers as $header => $value) {
  my_preferred_header_function_for_my_framework($header . ': ' . $value);
}

$zip->finish();

My experience with trying to send my own headers seemed to cause the zip to not download as a file (despite setting content disposition and filename and mimetype etc). I'll look at that again.

So the instructions for 2.4 are:

1. disable sending http headers (this is default so just make sure you aren't enabling it).
2. Send your own headers however you normally would do in your framework (or via raw php function header())
3. Finish the zip stream.

Is that correct? Thanks again.

[maennchen]

I would send the headers before you add the first file. Otherwise you’ll already be streaming the content and can no longer set headers.

The rest makes sense 👍