search

mscdex / busboy

A streaming parser for HTML form data for node.js
MIT License
2.84k stars 213 forks source link

readme

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

Install

npm install busboy

Examples

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!
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.

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