Awesome
Description
A node.js module for parsing incoming HTML form data.
Changes (breaking or otherwise) in v1.0.0 can be found here.
Note: If you are using node v18.0.0 or newer, please be aware of the node.js
HTTP(S) server's requestTimeout
configuration setting that is now enabled by default, which could cause upload
interruptions if the upload takes too long.
Requirements
- node.js -- v10.16.0 or newer
Install
npm install busboy
Examples
- Parsing (multipart) with default options:
const http = require('http');
const busboy = require('busboy');
http.createServer((req, res) => {
if (req.method === 'POST') {
console.log('POST request');
const bb = busboy({ headers: req.headers });
bb.on('file', (name, file, info) => {
const { filename, encoding, mimeType } = info;
console.log(
`File [${name}]: filename: %j, encoding: %j, mimeType: %j`,
filename,
encoding,
mimeType
);
file.on('data', (data) => {
console.log(`File [${name}] got ${data.length} bytes`);
}).on('close', () => {
console.log(`File [${name}] done`);
});
});
bb.on('field', (name, val, info) => {
console.log(`Field [${name}]: value: %j`, val);
});
bb.on('close', () => {
console.log('Done parsing form!');
res.writeHead(303, { Connection: 'close', Location: '/' });
res.end();
});
req.pipe(bb);
} else if (req.method === 'GET') {
res.writeHead(200, { Connection: 'close' });
res.end(`
<html>
<head></head>
<body>
<form method="POST" enctype="multipart/form-data">
<input type="file" name="filefield"><br />
<input type="text" name="textfield"><br />
<input type="submit">
</form>
</body>
</html>
`);
}
}).listen(8000, () => {
console.log('Listening for requests');
});
// Example output:
//
// Listening for requests
// < ... form submitted ... >
// POST request
// File [filefield]: filename: "logo.jpg", encoding: "binary", mime: "image/jpeg"
// File [filefield] got 11912 bytes
// Field [textfield]: value: "testing! :-)"
// File [filefield] done
// Done parsing form!
- Save all incoming files to disk:
const { randomFillSync } = require('crypto');
const fs = require('fs');
const http = require('http');
const os = require('os');
const path = require('path');
const busboy = require('busboy');
const random = (() => {
const buf = Buffer.alloc(16);
return () => randomFillSync(buf).toString('hex');
})();
http.createServer((req, res) => {
if (req.method === 'POST') {
const bb = busboy({ headers: req.headers });
bb.on('file', (name, file, info) => {
const saveTo = path.join(os.tmpdir(), `busboy-upload-${random()}`);
file.pipe(fs.createWriteStream(saveTo));
});
bb.on('close', () => {
res.writeHead(200, { 'Connection': 'close' });
res.end(`That's all folks!`);
});
req.pipe(bb);
return;
}
res.writeHead(404);
res.end();
}).listen(8000, () => {
console.log('Listening for requests');
});
API
Exports
busboy
exports a single function:
( function )(< object >config) - Creates and returns a new Writable form parser stream.
-
Valid
config
properties:-
headers - object - These are the HTTP headers of the incoming request, which are used by individual parsers.
-
highWaterMark - integer - highWaterMark to use for the parser stream. Default: node's stream.Writable default.
-
fileHwm - integer - highWaterMark to use for individual file streams. Default: node's stream.Readable default.
-
defCharset - string - Default character set to use when one isn't defined. Default:
'utf8'
. -
defParamCharset - string - For multipart forms, the default character set to use for values of part header parameters (e.g. filename) that are not extended parameters (that contain an explicit charset). Default:
'latin1'
. -
preservePath - boolean - If paths in filenames from file parts in a
'multipart/form-data'
request shall be preserved. Default:false
. -
limits - object - Various limits on incoming data. Valid properties are:
-
fieldNameSize - integer - Max field name size (in bytes). Default:
100
. -
fieldSize - integer - Max field value size (in bytes). Default:
1048576
(1MB). -
fields - integer - Max number of non-file fields. Default:
Infinity
. -
fileSize - integer - For multipart forms, the max file size (in bytes). Default:
Infinity
. -
files - integer - For multipart forms, the max number of file fields. Default:
Infinity
. -
parts - integer - For multipart forms, the max number of parts (fields + files). Default:
Infinity
. -
headerPairs - integer - For multipart forms, the max number of header key-value pairs to parse. Default:
2000
(same as node's http module).
-
-
This function can throw exceptions if there is something wrong with the values in config
. For example, if the Content-Type in headers
is missing entirely, is not a supported type, or is missing the boundary for 'multipart/form-data'
requests.
(Special) Parser stream events
-
file(< string >name, < Readable >stream, < object >info) - Emitted for each new file found.
name
contains the form field name.stream
is a Readable stream containing the file's data. No transformations/conversions (e.g. base64 to raw binary) are done on the file's data.info
contains the following properties:-
filename
- string - If supplied, this contains the file's filename. WARNING: You should almost never use this value as-is (especially if you are usingpreservePath: true
in yourconfig
) as it could contain malicious input. You are better off generating your own (safe) filenames, or at the very least using a hash of the filename. -
encoding
- string - The file's'Content-Transfer-Encoding'
value. -
mimeType
- string - The file's'Content-Type'
value.
Note: If you listen for this event, you should always consume the
stream
whether you care about its contents or not (you can simply dostream.resume();
if you want to discard/skip the contents), otherwise the'finish'
/'close'
event will never fire on the busboy parser stream. However, if you aren't accepting files, you can either simply not listen for the'file'
event at all or setlimits.files
to0
, and any/all files will be automatically skipped (these skipped files will still count towards any configuredlimits.files
andlimits.parts
limits though).Note: If a configured
limits.fileSize
limit was reached for a file,stream
will both have a boolean propertytruncated
set totrue
(best checked at the end of the stream) and emit a'limit'
event to notify you when this happens. -
-
field(< string >name, < string >value, < object >info) - Emitted for each new non-file field found.
name
contains the form field name.value
contains the string value of the field.info
contains the following properties:-
nameTruncated
- boolean - Whethername
was truncated or not (due to a configuredlimits.fieldNameSize
limit) -
valueTruncated
- boolean - Whethervalue
was truncated or not (due to a configuredlimits.fieldSize
limit) -
encoding
- string - The field's'Content-Transfer-Encoding'
value. -
mimeType
- string - The field's'Content-Type'
value.
-
-
partsLimit() - Emitted when the configured
limits.parts
limit has been reached. No more'file'
or'field'
events will be emitted. -
filesLimit() - Emitted when the configured
limits.files
limit has been reached. No more'file'
events will be emitted. -
fieldsLimit() - Emitted when the configured
limits.fields
limit has been reached. No more'field'
events will be emitted.