Uploading files using Skipper with Sails.js v0.10 - how to retrieve new file name

Question

I am upgrading to Sails.js version 0.10 and now need to use Skipper to manage my file uploads.

When I upload a file I generate a new name for it using a UUID, and save it in the public/files/ folder (this will change when I've got this all working but it's good for testing right now)

I save the original name, and the uploaded name + path into a Mongo database.

This was all quite straightforward under Sails v0.9.x but using Skipper I can't figure out how to read the new file name and path. (Obviously if I could read the name I could construct the path though so it's really only the name I need)

My Controller looks like this

var uuid = require('node-uuid'),
    path = require('path'),
    blobAdapter = require('skipper-disk');

module.exports = {

  upload: function(req, res) {

    var receiver = blobAdapter().receive({
          dirname: sails.config.appPath + "/public/files/",
          saveAs: function(file) {
            var filename = file.filename,
                newName = uuid.v4() + path.extname(filename);
            return newName;
          }
        }),
        results = [];

    req.file('docs').upload(receiver, function (err, files) {
      if (err) return res.serverError(err);
      async.forEach(files, function(file, next) {
        Document.create({
          name: file.filename,
          size: file.size,
          localName: // ***** how do I get the `saveAs()` value from the uploaded file *****,
          path: // *** and likewise how do i get the path ******
        }).exec(function(err, savedFile){
          if (err) {
            next(err);
          } else {
            results.push({
              id: savedFile.id,
              url: '/files/' + savedFile.localName
            });
            next();
          }
        });
      }, function(err){
        if (err) {
          sails.log.error('caught error', err);
          return res.serverError({error: err});
        } else {
          return res.json({ files: results });
        }
      });
    });
  },

  _config: {}

};

How do I do this?

Answer 1

I've worked this out now and thought I'd share my solution for the benefit of others struggling with similar issues.

The solution was to not use skipper-disk at all but to write my own custom receiver. I've created this as a Sails Service object.

So in file api/services/Uploader.js

// Uploader utilities and helper methods
// designed to be relatively generic.

var fs = require('fs'),
    Writable = require('stream').Writable;

exports.documentReceiverStream = function(options) {
  var defaults = {
    dirname: '/dev/null',
    saveAs: function(file){
      return file.filename;
    },
    completed: function(file, done){
      done();
    }
  };

  // I don't have access to jQuery here so this is the simplest way I
  // could think of to merge the options.
  opts = defaults;
  if (options.dirname) opts.dirname = options.dirname;
  if (options.saveAs) opts.saveAs = options.saveAs;
  if (options.completed) opts.completed = options.completed;

  var documentReceiver = Writable({objectMode: true});

  // This `_write` method is invoked each time a new file is received
  // from the Readable stream (Upstream) which is pumping filestreams
  // into this receiver.  (filename === `file.filename`).
  documentReceiver._write = function onFile(file, encoding, done) {
    var newFilename = opts.saveAs(file),
        fileSavePath = opts.dirname + newFilename,
        outputs = fs.createWriteStream(fileSavePath, encoding);
    file.pipe(outputs);

    // Garbage-collect the bytes that were already written for this file.
    // (called when a read or write error occurs)
    function gc(err) {
      sails.log.debug("Garbage collecting file '" + file.filename + "' located at '" + fileSavePath + "'");

      fs.unlink(fileSavePath, function (gcErr) {
        if (gcErr) {
          return done([err].concat([gcErr]));
        } else {
          return done(err);
        }
      });
    };

    file.on('error', function (err) {
      sails.log.error('READ error on file ' + file.filename, '::', err);
    });

    outputs.on('error', function failedToWriteFile (err) {
      sails.log.error('failed to write file', file.filename, 'with encoding', encoding, ': done =', done);
      gc(err);
    });

    outputs.on('finish', function successfullyWroteFile () {
      sails.log.debug("file uploaded")
      opts.completed({
        name: file.filename,
        size: file.size,
        localName: newFilename,
        path: fileSavePath
      }, done);
    });
  };

  return documentReceiver;
}

and then my controller just became (in api/controllers/DocumentController.js)

var uuid = require('node-uuid'),
    path = require('path');

module.exports = {

  upload: function(req, res) {

    var results = [],
        streamOptions = {
          dirname: sails.config.appPath + "/public/files/",
          saveAs: function(file) {
            var filename = file.filename,
                newName = uuid.v4() + path.extname(filename);
            return newName;
          },
          completed: function(fileData, next) {
            Document.create(fileData).exec(function(err, savedFile){
              if (err) {
                next(err);
              } else {
                results.push({
                  id: savedFile.id,
                  url: '/files/' + savedFile.localName
                });
                next();
              }
            });
          }
        };

    req.file('docs').upload(Uploader.documentReceiverStream(streamOptions),
      function (err, files) {
        if (err) return res.serverError(err);

        res.json({
          message: files.length + ' file(s) uploaded successfully!',
          files: results
        });
      }
    );
  },

  _config: {}
};

I'm sure it can be improved further but this works perfectly for me.