A Download object is usually created by calling [[Collection::get()]] or [[Collection::createDownload()]].
Usage example:
php
Yii::$app->mongodb->getFileCollection()->createDownload($document['_id'])->toFile('/path/to/file.dat');
You can use Download::substr() to read a specific part of the file:
php
$filePart = Yii::$app->mongodb->getFileCollection()->createDownload($document['_id'])->substr(256, 1024);
/**
* Prepares [[Download]] instance for the read operations.
* @return bool success.
* @throws InvalidConfigException on invalid context configuration.
*/
private function prepareDownload()
{
$contextOptions = $this->getContextOptions();
if (isset($contextOptions[$this->protocol]['download'])) {
$download = $contextOptions[$this->protocol]['download'];
if (!$download instanceof Download) {
throw new InvalidConfigException('"download" context option should be an instance of "' . Download::className() . '"');
}
$this->download = $download;
return true;
}
$collection = $this->fetchCollection();
if (empty($this->queryParams)) {
return false;
}
$file = $collection->findOne($this->queryParams);
if (empty($file)) {
throw new InvalidConfigException('Requested file does not exits.');
}
$this->download = $file['file'];
return true;
}
