|                                                                                                                                                                                                                         |  | # formstream
[![NPM version][npm-image]][npm-url][](https://github.com/node-modules/formstream/actions/workflows/ci.yml)[![Test coverage][codecov-image]][codecov-url][![npm download][download-image]][download-url]
[npm-image]: https://img.shields.io/npm/v/formstream.svg?style=flat-square[npm-url]: https://npmjs.org/package/formstream[codecov-image]: https://codecov.io/github/node-modules/formstream/coverage.svg?branch=master[codecov-url]: https://codecov.io/github/node-modules/formstream?branch=master[download-image]: https://img.shields.io/npm/dm/formstream.svg?style=flat-square[download-url]: https://npmjs.org/package/formstream
A [multipart/form-data](http://tools.ietf.org/html/rfc2388) encoded stream, helper for file upload.
## Install
```bashnpm install formstream```
## Quick Start
```jsvar 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 fieldsform.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
```jsvar 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.
```jsvar 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](http://nodejs.org/api/stream.html#stream_class_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
```jsvar 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](http://nodejs.org/api/stream.html#stream_event_data) for more.
### Event 'end'
Emitted when the stream has received no more 'data' events will happen.
See [Node.js Documentation](http://nodejs.org/api/stream.html#stream_event_end) for more.
## License
[MIT](LICENSE)
<!-- GITCONTRIBUTOR_START -->
## Contributors
|[<img src="https://avatars.githubusercontent.com/u/156269?v=4" width="100px;"/><br/><sub><b>fengmk2</b></sub>](https://github.com/fengmk2)<br/>|[<img src="https://avatars.githubusercontent.com/u/288288?v=4" width="100px;"/><br/><sub><b>xingrz</b></sub>](https://github.com/xingrz)<br/>|[<img src="https://avatars.githubusercontent.com/u/32174276?v=4" width="100px;"/><br/><sub><b>semantic-release-bot</b></sub>](https://github.com/semantic-release-bot)<br/>|[<img src="https://avatars.githubusercontent.com/u/13151189?v=4" width="100px;"/><br/><sub><b>fjc0k</b></sub>](https://github.com/fjc0k)<br/>|[<img src="https://avatars.githubusercontent.com/u/18096247?v=4" width="100px;"/><br/><sub><b>mrspeiser</b></sub>](https://github.com/mrspeiser)<br/>|[<img src="https://avatars.githubusercontent.com/u/985607?v=4" width="100px;"/><br/><sub><b>dead-horse</b></sub>](https://github.com/dead-horse)<br/>|| :---: | :---: | :---: | :---: | :---: | :---: |[<img src="https://avatars.githubusercontent.com/u/7326406?v=4" width="100px;"/><br/><sub><b>shaozj</b></sub>](https://github.com/shaozj)<br/>
This project follows the git-contributor [spec](https://github.com/xudafeng/git-contributor), auto updated at `Wed May 15 2024 00:34:12 GMT+0800`.
<!-- GITCONTRIBUTOR_END -->
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