# Form-Data [![NPM Module](https://img.shields.io/npm/v/form-data.svg)](https://www.npmjs.com/package/form-data) [![Join the chat at https://gitter.im/form-data/form-data](http://form-data.github.io/images/gitterbadge.svg)](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].
// 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:
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:
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):