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.
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:
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:
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:
form.submit('http://example.org/', function(err, res) {
// res โ 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
:
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:
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:
form.submit('example.org/upload', function(err, res) {
console.log(res.statusCode);
});
To use custom headers and pre-known length in parts:
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:
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:
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()
:
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:
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:
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);
});
In Node.js you can post a file using axios:
const form = new FormData();
const stream = fs.createReadStream(PATH_TO_FILE);
form.append('image', stream);
// In Node.js environment you need to set boundary in the header field 'Content-Type' by calling method `getHeaders`
const formHeaders = form.getHeaders();
axios.post('http://example.com', form, {
headers: {
...formHeaders,
},
})
.then(response => response)
.catch(error => error)
getLengthSync()
method DOESN'T calculate length for streams, useknownLength
options as workaround.- Starting version
2.x
FormData has dropped support for[email protected]
.
Form-Data is released under the MIT license.