Feathers.js multipart/file-data Upload Middleware

README.md

Feathers.js multipart/file-data Upload middleware

Parses multipart/form-data uploads and stream files to a blob-store.
After uploading the Services receives a json-body with the file references:

{
  "files": [
    {
      "key": "34525ca2-f774-444f-8e7e-7622bef69cb1",
      "filename": "13.jpg",
      "mimetype": "image/jpeg"
    },
    {
      "key": "7d757e42-23aa-4df3-8995-d4b8047d6a65",
      "filename": "06.jpg",
      "mimetype": "image/jpeg"
    }
  ],
  "createdAt": "2016-12-13T19:22:27.552Z",
  "_id": "Z3W69V7mcUPYfye3"
}

TODO

• Add md5sum to meta?
• Add length to meta?
• How to check permissions

files-service.js

'use strict';

const path = require('path');
const NeDB = require('nedb');
const service = require('feathers-nedb');
const hooks = require('./hooks');
const uploader = require('./upload');
const store = require('fs-blob-store')(path.resolve(__dirname + '/../../../data/files'));

module.exports = function(){
  const app = this;

  const db = new NeDB({
    filename: path.join(app.get('nedb'), 'files.db'),
    autoload: true
  });
  db.persistence.setAutocompactionInterval(24 * 3600);

  let options = {
    Model: db,
    paginate: {
      default: 5,
      max: 25
    }
  };

  app.use('/files', uploader(store), service(options));

  const filesService = app.service('/files');
  filesService.before(hooks.before);
  filesService.after(hooks.after);
};

upload.js

'use strict';
const Busboy = require('busboy');
const uuidGen = require('uuid/v4');
const debug = require('debug')('upload');

module.exports = function(store) {
  if(typeof store.createWriteStream !== 'function') {
    // see https://github.com/maxogden/abstract-blob-store
    throw new Error('Store has to be an abstract-blob-store compatible Instance')
  }

  return function upload(req, res, next) {
    // Only for POST Requests of Type multipart/form-data
    if(req.method !== 'POST' || !req.headers['content-type'].startsWith('multipart/form-data')) {
      return next();
    }
    debug('Received multipart/form-data POST on '+ req.url);

    req.body = { files: [] };
    let uploading = 0, finished = false;
    const busboy = new Busboy({headers: req.headers});

    function done() {
      // be sure busboy and every store-write is finished
      if(uploading > 0 || !finished) return;
      debug('Finished multipart/form-data POST on ' + req.url);
      next();
    }

    // Listen for event when Busboy finds a file to stream.
    busboy.on('file', function(fieldname, stream, filename, encoding, mimetype) {
      debug('Uploading file ' + filename);
      uploading++;

      const meta = {
        key: uuidGen(),
        filename,
        mimetype
      };

      const storeWS = store.createWriteStream(meta, function(err, data) {
        uploading--;
        if(err) return console.error(err);
        debug('Uploaded ' + filename);
        req.body.files.push(data);
        done();
      });

      // Pipe the file into store
      stream.pipe(storeWS);
    });

    // adopt non file fields to body
    busboy.on('field', function(fieldname, val) {
      req.body[fieldname] = val;
    });

    // Listen for event when Busboy is finished parsing the form
    busboy.on('finish', function() {
      finished = true;
      done();
    });

    // Pipe the HTTP Request into Busboy
    req.pipe(busboy);
  };
};