Download Sails JS Skipper v0.10.5 Files

I upload files with skipper, everything works fine, but I have a problem with save parameter. I assign its value using a function, but it doesn't work, how can I assign the value to req. param ('titulo') + file extension for saveAs option?

var path = require('path');

module.exports = {

'save':function(req,res,next){

    var uploadOptions = {
        dirname: sails.config.appPath + '/assets/books',
        saveAs: function(file){
            return req.param('titulo')+path.extname(file.filename);
        },
        maxBytes: 20 * 1000 * 1000
    }

    req.file('archivoPath').upload(uploadOptions,function(err,files){
        if(err){
            return res.serverError(err);
        }
        else{
            console.log(files);
        }
    });

    Book.create(req.params.all(),function bookCreated(err,book,next){
        if(err) {
            console.log(err);
        }
        return res.redirect('/book/books');
    });
}

};

      

        
        
        
      

    

I also really want to know if inside folder files would be a good place to download the PDF to show in my interface.