yii\mongodb\file\ActiveRecord::getFileContent PHP Метод

    public function getFileContent()
    {
        $file = $this->getAttribute('file');
        if (empty($file) && !$this->getIsNewRecord()) {
            $file = $this->refreshFile();
        }
        if (empty($file)) {
            return null;
        } elseif ($file instanceof Download) {
            $fileSize = $file->getSize();
            if (empty($fileSize)) {
                return null;
            } else {
                return $file->toString();
            }
        } elseif ($file instanceof UploadedFile) {
            return file_get_contents($file->tempName);
        } elseif (is_string($file)) {
            if (file_exists($file)) {
                return file_get_contents($file);
            } else {
                throw new InvalidParamException("File '{$file}' does not exist.");
            }
        } else {
            throw new InvalidParamException('Unsupported type of "file" attribute.');
        }
    }