# Form-Data [](https://www.npmjs.com/package/form-data) [](https://gitter.im/form-data/form-data) A library to create readable ```"multipart/form-data"``` streams. Can be used to submit forms and file uploads to other web applications. The API of this library is inspired by the [XMLHttpRequest-2 FormData Interface][xhr2-fd]. [xhr2-fd]: http://dev.w3.org/2006/webapi/XMLHttpRequest-2/Overview.html#the-formdata-interface [](https://travis-ci.org/form-data/form-data) [](https://travis-ci.org/form-data/form-data) [](https://ci.appveyor.com/project/alexindigo/form-data) [](https://coveralls.io/github/form-data/form-data?branch=master) [](https://david-dm.org/form-data/form-data) [](https://www.bithound.io/github/form-data/form-data) ## Install ``` npm install --save form-data ``` ## Usage In this example we are constructing a form with 3 fields that contain a string, a buffer and a file stream. ``` javascript var FormData = require('form-data'); var fs = require('fs'); var form = new FormData(); form.append('my_field', 'my value'); form.append('my_buffer', new Buffer(10)); form.append('my_file', fs.createReadStream('/foo/bar.jpg')); ``` Also you can use http-response stream: ``` javascript var FormData = require('form-data'); var http = require('http'); var form = new FormData(); http.request('http://nodejs.org/images/logo.png', function(response) { form.append('my_field', 'my value'); form.append('my_buffer', new Buffer(10)); form.append('my_logo', response); }); ``` Or @mikeal's [request](https://github.com/request/request) stream: ``` javascript var FormData = require('form-data'); var request = require('request'); var form = new FormData(); form.append('my_field', 'my value'); form.append('my_buffer', new Buffer(10)); form.append('my_logo', request('http://nodejs.org/images/logo.png')); ``` In order to submit this form to a web application, call ```submit(url, [callback])``` method: ``` javascript form.submit('http://example.org/', function(err, res) { // res – response object (http.IncomingMessage) // res.resume(); }); ``` For more advanced request manipulations ```submit()``` method returns ```http.ClientRequest``` object, or you can choose from one of the alternative submission methods. ### Custom options You can provide custom options, such as `maxDataSize`: ``` javascript var FormData = require('form-data'); var form = new FormData({ maxDataSize: 20971520 }); form.append('my_field', 'my value'); form.append('my_buffer', /* something big */); ``` List of available options could be found in [combined-stream](https://github.com/felixge/node-combined-stream/blob/master/lib/combined_stream.js#L7-L15) ### Alternative submission methods You can use node's http client interface: ``` javascript var http = require('http'); var request = http.request({ method: 'post', host: 'example.org', path: '/upload', headers: form.getHeaders() }); form.pipe(request); request.on('response', function(res) { console.log(res.statusCode); }); ``` Or if you would prefer the `'Content-Length'` header to be set for you: ``` javascript form.submit('example.org/upload', function(err, res) { console.log(res.statusCode); }); ``` To use custom headers and pre-known length in parts: ``` javascript var CRLF = '\r\n'; var form = new FormData(); var options = { header: CRLF + '--' + form.getBoundary() + CRLF + 'X-Custom-Header: 123' + CRLF + CRLF, knownLength: 1 }; form.append('my_buffer', buffer, options); form.submit('http://example.com/', function(err, res) { if (err) throw err; console.log('Done'); }); ``` Form-Data can recognize and fetch all the required information from common types of streams (```fs.readStream```, ```http.response``` and ```mikeal's request```), for some other types of streams you'd need to provide "file"-related information manually: ``` javascript someModule.stream(function(err, stdout, stderr) { if (err) throw err; var form = new FormData(); form.append('file', stdout, { filename: 'unicycle.jpg', // ... or: filepath: 'photos/toys/unicycle.jpg', contentType: 'image/jpeg', knownLength: 19806 }); form.submit('http://example.com/', function(err, res) { if (err) throw err; console.log('Done'); }); }); ``` The `filepath` property overrides `filename` and may contain a relative path. This is typically used when uploading [multiple files from a directory](https://wicg.github.io/entries-api/#dom-htmlinputelement-webkitdirectory). For edge cases, like POST request to URL with query string or to pass HTTP auth credentials, object can be passed to `form.submit()` as first parameter: ``` javascript form.submit({ host: 'example.com', path: '/probably.php?extra=params', auth: 'username:password' }, function(err, res) { console.log(res.statusCode); }); ``` In case you need to also send custom HTTP headers with the POST request, you can use the `headers` key in first parameter of `form.submit()`: ``` javascript form.submit({ host: 'example.com', path: '/surelynot.php', headers: {'x-test-header': 'test-header-value'} }, function(err, res) { console.log(res.statusCode); }); ``` ### Integration with other libraries #### Request Form submission using [request](https://github.com/request/request): ```javascript var formData = { my_field: 'my_value', my_file: fs.createReadStream(__dirname + '/unicycle.jpg'), }; request.post({url:'http://service.com/upload', formData: formData}, function(err, httpResponse, body) { if (err) { return console.error('upload failed:', err); } console.log('Upload successful! Server responded with:', body); }); ``` For more details see [request readme](https://github.com/request/request#multipartform-data-multipart-form-uploads). #### node-fetch You can also submit a form using [node-fetch](https://github.com/bitinn/node-fetch): ```javascript var form = new FormData(); form.append('a', 1); fetch('http://example.com', { method: 'POST', body: form }) .then(function(res) { return res.json(); }).then(function(json) { console.log(json); }); ``` ## Notes - ```getLengthSync()``` method DOESN'T calculate length for streams, use ```knownLength``` options as workaround. - Starting version `2.x` FormData has dropped support for `node@0.10.x`. ## License Form-Data is released under the [MIT](License) license.