private function addElement(AppendStream $stream, array $element)
{
foreach (['contents', 'name'] as $key) {
if (!array_key_exists($key, $element)) {
throw new \InvalidArgumentException("A '{$key}' key is required");
}
}
$element['contents'] = stream_for($element['contents']);
if (empty($element['filename'])) {
$uri = $element['contents']->getMetadata('uri');
if (substr($uri, 0, 6) !== 'php://') {
$element['filename'] = $uri;
}
}
list($body, $headers) = $this->createElement($element['name'], $element['contents'], isset($element['filename']) ? $element['filename'] : null, isset($element['headers']) ? $element['headers'] : []);
$stream->addStream(stream_for($this->getHeaders($headers)));
$stream->addStream($body);
$stream->addStream(stream_for("\r\n"));
}