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.
npm install --save form-data
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 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.
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
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.
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);
});
Form submission using 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.
You can also submit a form using 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); }); ```
getLengthSync() method DOESN'T calculate length for streams, use knownLength options as workaround.2.x FormData has dropped support for node@0.10.x.Form-Data is released under the MIT license.