Enables use of formidable (node.js module for parsing form data, especially file uploads) in serverless environments.
npm install formidable-serverless
This module is a variant of formidable with tweaks to enable use in serverless environments (AWS Lambda, Firebase/Google Cloud Functions, etc.) and environments where the request has already been processed (e.g. by bodyparser).
The functionality and usage/API are identical to formidable (documentation cloned below).
Sponsored and maintained by the folks at testmail.app
The preprocessing by bodyparsers built-in to serverless environments breaks formidable's parse handlers and causes "Request Aborted" errors. This module imports formidable as a dependency and modifies the handlers to support preprocessed request bodies.
This module can also be used in non-serverless environments (usage and API are identical), but it may be a version or two behind. This package is focused on serverless - if you have issues with formidable itself, please open them in the formidable repo.
A Node.js module for parsing form data, especially file uploads.
Formidable was developed for Transloadit, a service focused on uploading and encoding images and videos. It has been battle-tested against hundreds of GB of file uploads from a large variety of clients and is considered production-ready.
* Fast (~500mb/sec), non-buffering multipart parser
* Automatically writing file uploads to disk
* Low memory footprint
* Graceful error handling
* Very high test coverage
``sh`
npm install --save formidable-serverless
This is a low-level package, and if you're using a high-level framework it may already be included. However, Express v4 does not include any multipart handling, nor does body-parser.
Parse an incoming file upload.
`javascript
const formidable = require('formidable-serverless');
const http = require('http');
const util = require('util');
http.createServer(function(req, res) {
if (req.url == '/upload' && req.method.toLowerCase() == 'post') {
// parse a file upload
const form = new formidable.IncomingForm();
form.parse(req, function(err, fields, files) {
res.writeHead(200, {'content-type': 'text/plain'});
res.write('received upload:\n\n');
res.end(util.inspect({fields: fields, files: files}));
});
return;
}
// show a file upload form
res.writeHead(200, {'content-type': 'text/html'});
res.end(
'
API
$3
javascript
var form = new formidable.IncomingForm()
`Creates a new incoming form.
javascript
form.encoding = 'utf-8';
`Sets encoding for incoming form fields.
javascript
form.uploadDir = "/my/dir";
`Sets the directory for placing file uploads in. You can move them later on using
. The default is os.tmpdir().`javascript
form.keepExtensions = false;
`If you want the files written to
to include the extensions of the original files, set this property to true.`javascript
form.type
`Either 'multipart' or 'urlencoded' depending on the incoming request.
javascript
form.maxFieldsSize = 20 1024 1024;
`Limits the amount of memory all fields together (except files) can allocate in bytes. If this value is exceeded, an
event is emitted. The default size is 20MB.`javascript
form.maxFileSize = 200 1024 1024;
`Limits the size of uploaded file. If this value is exceeded, an
event is emitted. The default size is 200MB.`javascript
form.maxFields = 1000;
`Limits the number of fields that the querystring parser will decode. Defaults to 1000 (0 for unlimited).
javascript
form.hash = false;
`If you want checksums calculated for incoming files, set this to either
or 'md5'.`javascript
form.multiples = false;
`If this option is enabled, when you call
, the files argument will contain arrays of files for inputs which submit multiple files using the HTML5 multiple attribute.`javascript
form.bytesReceived
`The amount of bytes received for this form so far.
javascript
form.bytesExpected
`The expected number of bytes in this form.
javascript
form.parse(request, [cb]);
`Parses an incoming node.js
containing form data. If cb is provided, all fields and files are collected and passed to the callback:`javascript
form.parse(req, function(err, fields, files) {
// ...
});form.onPart(part);
`You may overwrite this method if you are interested in directly accessing the multipart stream. Doing so will disable any
/ 'file' events processing which would occur otherwise, making you fully responsible for handling the processing.`javascript
form.onPart = function(part) {
part.addListener('data', function() {
// ...
});
}
`If you want to use formidable to only handle certain parts for you, you can do so:
javascript
form.onPart = function(part) {
if (!part.filename) {
// let formidable handle all non-file parts
form.handlePart(part);
}
}
`Check the code in this method for further inspiration.
$3
javascript
file.size = 0
`The size of the uploaded file in bytes. If the file is still being uploaded (see
event), this property says how many bytes of the file have been written to disk yet.`javascript
file.path = null
`The path this file is being written to. You can modify this in the
event in case you are unhappy with the way formidable generates a temporary path for your files.`javascript
file.name = null
`The name this file had according to the uploading client.
javascript
file.type = null
`The mime type of this file, according to the uploading client.
javascript
file.lastModifiedDate = null
`A date object (or
) containing the time this file was last written to. Mostly here for compatibility with the W3C File API Draft.`javascript
file.hash = null
`If hash calculation was set, you can read the hex digest out of this var.
#### Formidable.File#toJSON()
This method returns a JSON-representation of the file, allowing you to
the file which is useful for logging and responding to requests.$3
#### 'progress'
Emitted after each incoming chunk of data that has been parsed. Can be used to roll your own progress bar.
`javascript
form.on('progress', function(bytesReceived, bytesExpected) {
});
`#### 'field'
Emitted whenever a field / value pair has been received.
javascript
form.on('field', function(name, value) {
});
`#### 'fileBegin'
Emitted whenever a new file is detected in the upload stream. Use this event if you want to stream the file to somewhere else while buffering the upload on the file system.
javascript
form.on('fileBegin', function(name, file) {
});
`#### 'file'
Emitted whenever a field / file pair has been received.
is an instance of File.`javascript
form.on('file', function(name, file) {
});
`#### 'error'
Emitted when there is an error processing the incoming form. A request that experiences an error is automatically paused, you will have to manually call
if you want the request to continue firing 'data' events.`javascript
form.on('error', function(err) {
});
`#### 'aborted'
Emitted when the request was aborted by the user. Right now this can be due to a 'timeout' or 'close' event on the socket. After this event is emitted, an
event will follow. In the future there will be a separate 'timeout' event (needs a change in the node core).`javascript
form.on('aborted', function() {
});
`##### 'end'
javascript
form.on('end', function() {
});
``Emitted when the entire request has been received, and all contained files have finished flushing to disk. This is a great place for you to send your response.
Formidable and formidable-serverless are licensed under the MIT license.