private function getNameOfFirstSubfolder($pluginDir)
{
if (!($dir = opendir($pluginDir))) {
return false;
}
$firstSubFolder = '';
while ($file = readdir($dir)) {
if ($file[0] != '.' && is_dir($pluginDir . DIRECTORY_SEPARATOR . $file)) {
$firstSubFolder = $file;
break;
}
}
if (empty($firstSubFolder)) {
throw new PluginInstallerException('The plugin ZIP file does not contain a subfolder, but Piwik expects plugin files to be within a subfolder in the Zip archive.');
}
return $firstSubFolder;
}