public function writeFile($filename)
{
$file = $this->getAttribute('file');
if (empty($file) && !$this->getIsNewRecord()) {
$file = $this->refreshFile();
}
if (empty($file)) {
throw new InvalidParamException('There is no file associated with this object.');
} elseif ($file instanceof Download) {
return $file->toFile($filename) == $file->getSize();
} elseif ($file instanceof UploadedFile) {
return copy($file->tempName, $filename);
} elseif (is_string($file)) {
if (file_exists($file)) {
return copy($file, $filename);
} else {
throw new InvalidParamException("File '{$file}' does not exist.");
}
} else {
throw new InvalidParamException('Unsupported type of "file" attribute.');
}
}