Multipart with JSON

[magalhas]

Hi,

Can you please let me know how to attach a file and send the rest of the data as JSON? I've tried using req.part() but it has been deprecated.

Thanks.

[magalhas]

No one?

[huang-xiao-jian]

Actually, I don't understand the description quite well, but code below may be helpful for you.

backend data resolve first.

var express = require('express');
var multer = require('multer');

var app = express();
app.post('/',  multer({
    inMemory: true,
    includeEmptyFields: true
}), function(req, res) {
    /*
     req.files contains file information
     req.body contains other non-file information
     */
    res.json(req.body);
});
app.listen(1337);

superagent with multipart

var request = require('superagent');
var should = require('should');

describe('superagent', function () {
    it('with multi part', function (done) {
        request
            .post('http://localhost:1337')
            .field('name', 'born')
            .field('age', 23)
            .attach('package', 'package.json')
            .attach('index', 'index.js')
            .end(function(res) {
                try {
                    res.body.should.eql({
                        "name": "born",
                        "age": "23"
                    });
                    done();
                } catch (err) {
                    done(err);
                }
            });
    });
});

In theory, supertagent support both part lower-level and field, attach higher-level api . @magalhas

[zbyte64]

Okay two things,

Is part really deprecated? If so shouldn't it be removed from the docs?

Can attach accept a file stream or a blob of text isntead of reading from a filename?

[formula1]

It appears this was not answered

Heres what I have found if it helps anyone

• superagent basically is just a wrapper around the form-data module when it comes to multipart post calls. The wrapper transforms strings into readable streams so your best to expect that a normal stream should work as well
• form-data's append method is a wrapper around combined-stream's append.
• combined-stream's converts all streams into a delayed stream then pushes the value (regardless of whether its a stream or not) on the list of streams
• combined-stream's way of handling its list of streams is pretty straight forward. If its a stream, it pipes. If it isn't it just writes the values.

In other words passing a blob or a readableStream seems to be fine.

If you want to pass a content type, you must provide a exstension that will qualify as the type you want. This seems straightforward however it is not in all cases since if you want to send a file as application/x-patch that will not be possible as it is not in the mime-db

Update - I was wrong on the arbitrary readable stream.

[misha-slyusarev]

I'm using superagent with React and Rails and trying to compose a multipart request for the backend.

Is there a way to add a JS object to the request without adding it field by field? For instance, I would like to have {'invoice' => {'recipient_attributes' => {'name' => 'myname', 'last_name' => 'mylastname'}, 'attachment' => ... } as my params in Rails backend part. And that's how I'm trying to do it:

request.post('v1/invoices')
      .field('invoice[recipient_attributes]', this.state.recipient)
      .attach('invoice[attachment]', this.state.invoiceFile)
      .end(function(err, res){
        console.log('invoiceInfo submitted')
      });

But recipient_attributes is saved as '[object Object]' instead of expected. Is there a way to add the whole object, or I have to add fields one by one like this:

.field('invoice[recipient_attributes][name]', 'myname')
.field('invoice[recipient_attributes][last_name]', 'mylastname')

Thank you in advance!

[kornelski]

You have to add fields one by one.

[ollyde]

The fields get converted to strings and fail validation.

[maliksblr92]

life saver