formstream

What is formstream?

The formstream npm package is used to create multipart/form-data streams, which are useful for uploading files and data via HTTP requests. It simplifies the process of constructing form data streams, making it easier to handle file uploads in Node.js applications.

What are formstream's main functionalities?

Create a form stream

This feature allows you to create a form stream, add fields and files to it, and then generate the stream for use in an HTTP request.

const formstream = require('formstream');
const form = formstream();
form.field('name', 'value');
form.file('file', '/path/to/file');
form.stream();

Add fields to the form

This feature allows you to add text fields to the form stream. Each field is added with a key-value pair.

const form = formstream();
form.field('username', 'john_doe');
form.field('email', '[e-mail]');

Add files to the form

This feature allows you to add files to the form stream. Each file is added with a key and the file path.

const form = formstream();
form.file('profile_picture', '/path/to/profile.jpg');

Generate the form stream

This feature generates the form stream after adding all the fields and files. The generated stream can then be used in an HTTP request.

const form = formstream();
form.field('username', 'john_doe');
form.file('profile_picture', '/path/to/profile.jpg');
const stream = form.stream();

Other packages similar to formstream

form-data

The form-data package is a module to create readable 'multipart/form-data' streams. It is similar to formstream in that it allows you to construct form data streams for file uploads. However, form-data is more widely used and has more extensive documentation and community support.

multiparty

The multiparty package is a module for parsing multipart/form-data, which is commonly used for file uploads. Unlike formstream, which focuses on creating form data streams, multiparty is used for parsing incoming form data streams. It is useful for handling file uploads on the server side.

busboy

The busboy package is a fast and low-level module for parsing incoming HTML form data. It is similar to multiparty in that it is used for parsing form data streams, but it is known for its performance and efficiency. It is a good choice for handling large file uploads.

README

formstream

A multipart/form-data encoded stream, helper for file upload.

Install

npm install formstream

Quick Start

var formstream = require('formstream');
var http = require('http');

var form = formstream();

// form.file('file', filepath, filename);
form.file('file', './logo.png', 'upload-logo.png');

// other form fields
form.field('foo', 'fengmk2').field('love', 'aerdeng');

// even send file content buffer directly
// form.buffer(name, buffer, filename, mimeType)
form.buffer('file2', new Buffer('This is file2 content.'), 'foo.txt');

var options = {
  method: 'POST',
  host: 'upload.cnodejs.net',
  path: '/store',
  headers: form.headers()
};
var req = http.request(options, function (res) {
  console.log('Status: %s', res.statusCode);
  res.on('data', function (data) {
    console.log(data.toString());
  });
});

form.pipe(req);

Chaining

var fs = require('fs');
var formstream = require('formstream');

var filepath = './logo.png';
fs.stat(filepath, function (err, stat) {
  formstream()
    .field('status', 'share picture')
    .field('access_token', 'your access token')
    .file('pic', filepath, 'logo.png', stat.size)
    .pipe(process.stdout); // your request stream
});

Set min chunk buffer size

Some web servers have a limit on the number of chunks, and you can set minChunkSize to ensure the size of chunk sent to the server.

var fs = require('fs');
var FormStream = require('formstream');

var filepath = './big-file.zip';
fs.stat(filepath, function (err, stat) {
  new FormStream({
    // send >= 2MB chunk buffer size to the server
    minChunkSize: 1024 * 1024 * 2,
  }).field('status', 'share file')
    .field('access_token', 'your access token')
    .file('file', filepath, 'big-file.zip', stat.size)
    .pipe(process.stdout); // your request stream
});

API Doc

formstream([options])

Create a form instance.

Arguments

• options.minChunkSize Number - min chunk size to emit data event

Returns

Form - form instance

FormStream#field(name, value)

Add a normal field to the form.

Arguments

• name String - Name of field
• value String - Value of field

Returns

Form - form instance

FormStream#file(name, filepath[, filename][, filesize])

Add a local file to be uploaded to the form.

Arguments

• name String - Name of file field
• filepath String - Local path of the file to be uploaded
• filename String - Optional. Name of the file (will be the base name of filepath if empty)
• filesize Number - Optional. Size of the file (will not generate Content-Length header if not specified)

Returns

Form - form instance

FormStream#buffer(name, buffer, filename[, contentType])

Add a buffer as a file to upload.

Arguments

• name String - Name of field
• buffer Buffer - The buffer to be uploaded
• filename String - The file name that tells the remote server
• contentType String - Optional. Content-Type (aka. MIME Type) of content (will be infered with filename if empty)

Returns

Form - form instance

FormStream#stream(name, stream, filename[, contentType][, size])

Add a readable stream as a file to upload. Event 'error' will be emitted if an error occured.

Arguments

• name String - Name of field
• stream stream.Readable - A readable stream to be piped
• filename String - The file name that tells the remote server
• contentType String - Optional. Content-Type (aka. MIME Type) of content (will be infered with filename if empty)
• size Number - Optional. Size of the stream (will not generate Content-Length header if not specified)

Returns

Form - form instance

FormStream#headers([headers])

Get headers for the request.

Arguments

• headers Object - Additional headers

Example

var headers = form.headers({
  'Authorization': 'Bearer kei2akc92jmznvnkeh09sknzdk',
  'Accept': 'application/vnd.github.v3.full+json'
});

Returns

Object - Headers to be sent.

Event 'error'

Emitted if there was an error receiving data.

Event 'data'

The 'data' event emits when a Buffer was used.

See Node.js Documentation for more.

Event 'end'

Emitted when the stream has received no more 'data' events will happen.

See Node.js Documentation for more.

License

MIT

Contributors

fengmk2	xingrz	semantic-release-bot	fjc0k	mrspeiser	dead-horse
shaozj

This project follows the git-contributor spec, auto updated at Wed May 15 2024 00:34:12 GMT+0800.

Changelog

1.5.1 (2024-06-07)

Bug Fixes

• only print top 512 bytes on buffer field debug log (#27) (9f771e8)