Connect

Multipart:

Status: Deprecated. The multipart parser will be removed in Connect 3.0.
Please use one of the following parsers/middleware directly:

Parse multipart/form-data request bodies,
providing the parsed object as req.body
and req.files.

Configuration:

The options passed are merged with multiparty's
Form object, allowing you to configure the upload directory,
size limits, etc. For example if you wish to change the upload dir do the following.

app.use(connect.multipart({ uploadDir: path }));

Options:

limit byte limit defaulting to [100mb]
defer defers processing and exposes the multiparty form object as req.form. next() is called without waiting for the form's "end" event. This option is useful if you need to bind to the "progress" or "part" events, for example.

Temporary Files:

By default temporary files are used, stored in os.tmpDir(). These
are not automatically garbage collected, you are in charge of moving them
or deleting them. When defer is not used and these files are created you
may refernce them via the req.files object.

req.files.images.forEach(function(file){
  console.log('  uploaded : %s %skb : %s', file.originalFilename, file.size / 1024 | 0, file.path);
});

It is highly recommended to monitor and clean up tempfiles in any production
environment, you may use tools like reap
to do so.

Streaming:

When defer is used files are not streamed to tmpfiles, you may
access them via the "part" events and stream them accordingly:

req.form.on('part', function(part){
  // transfer to s3 etc
  console.log('upload %s %s', part.name, part.filename);
  var out = fs.createWriteStream('/tmp/' + part.filename);
  part.pipe(out);
});

req.form.on('close', function(){
  res.end('uploaded!');
});

Object options
returns Function

Source

exports = module.exports = function(options){
  options = options || {};

  if (process.env.NODE_ENV !== 'test') {
    console.warn('connect.multipart() will be removed in connect 3.0');
    console.warn('visit https://github.com/senchalabs/connect/wiki/Connect-3.0 for alternatives');
  }

  var limit = _limit(options.limit || '100mb');

  return function multipart(req, res, next) {
    if (req._body) return next();
    req.body = req.body || {};
    req.files = req.files || {};

    if (!utils.hasBody(req)) return next();

    // ignore GET
    if ('GET' == req.method || 'HEAD' == req.method) return next();

    // check Content-Type
    if ('multipart/form-data' != utils.mime(req)) return next();

    // flag as parsed
    req._body = true;

    // parse
    limit(req, res, function(err){
      if (err) return next(err);

      var form = new multiparty.Form(options)
        , data = {}
        , files = {}
        , done;

      Object.keys(options).forEach(function(key){
        form[key] = options[key];
      });

      function ondata(name, val, data){
        if (Array.isArray(data[name])) {
          data[name].push(val);
        } else if (data[name]) {
          data[name] = [data[name], val];
        } else {
          data[name] = val;
        }
      }

      form.on('field', function(name, val){
        ondata(name, val, data);
      });

      if (!options.defer) {
        form.on('file', function(name, val){
          val.name = val.originalFilename;
          val.type = val.headers['content-type'] || null;
          ondata(name, val, files);
        });
      }

      form.on('error', function(err){
        if (!options.defer) {
          err.status = 400;
          next(err);
        }
        done = true;
      });

      form.on('close', function(){
        if (done) return;
        try {
          req.body = qs.parse(data);
          req.files = qs.parse(files);
        } catch (err) {
          form.emit('error', err);
          return;
        }
        if (!options.defer) next();
      });

      form.parse(req);

      if (options.defer) {
        req.form = form;
        next();
      }
    });
  }
};