Devise\Media\Files\Manager::saveUploadedFile PHP Method

    public function saveUploadedFile($input)
    {
        $file = array_get($input, 'file', null);
        if (is_null($file)) {
            return false;
        }
        $originalName = $file->getClientOriginalName();
        $localPath = isset($input['category']) ? $this->CategoryPaths->fromDot($input['category']) : '';
        $serverPath = $this->CategoryPaths->serverPath($localPath);
        $newName = $this->createFile($file, $serverPath, $originalName);
        if ($this->Image->canMakeThumbnailFromFile($file)) {
            $thumbnailPath = $this->getThumbnailPath($localPath . '/' . $newName);
            if (!is_dir(dirname($thumbnailPath))) {
                mkdir(dirname($thumbnailPath), 0755, true);
            }
            $this->Image->makeThumbnailImage($serverPath . $newName, $thumbnailPath, $file->getClientMimeType());
        }
        return $localPath . '/' . $newName;
    }