co busboy

busboy multipart parser using co or koa.

Example

1const parse = require('co-busboy')
2
3app.use(async (next) => {
4  // the body isn't multipart, so busboy can't parse it
5  if (!this.request.is('multipart/*')) return await next()
6
7  const parts = parse(this)
8  let part
9  while (part = await parts()) {
10    if (part.length) {
11      // arrays are busboy fields
12      console.log('key: ' + part[0])
13      console.log('value: ' + part[1])
14    } else {
15      // otherwise, it's a stream
16      part.pipe(fs.createWriteStream('some file.txt'))
17    }
18  }
19  console.log('and we are done parsing the form!')
20})

Note that parts will be delievered in the order they are defined in the form. Put your CSRF token first in the form and your larger files last.

If you want co-busboy to automatically handle the fields, set the autoFields: true option. Now all the parts will be streams and a field object and array will automatically be populated.

1const parse = require('co-busboy')
2
3app.use(async (next) => {
4  const parts = parse(this, {
5    autoFields: true
6  })
7  let part
8  while (part = await parts()) {
9    // it's a stream
10    part.pipe(fs.createWriteStream('some file.txt'))
11  }
12  console.log('and we are done parsing the form!')
13  // .field holds all the fields in key/value form
14  console.log(parts.field._csrf)
15  // .fields holds all the fields in [key, value] form
16  console.log(parts.fields[0])
17})

Example for csrf check

Use options.checkField hook function(name, val, fieldnameTruncated, valTruncated) can handle fields check.

1const parse = require('co-busboy')
2
3app.use(async (next) => {
4  const ctx = this
5  const parts = parse(this, {
6    checkField: (name, value) => {
7      if (name === '_csrf' && !checkCSRF(ctx, value)) {
8        var err =  new Error('invalid csrf token')
9        err.status = 400
10        return err
11      }
12    }
13  })
14  let part
15  while (part = await parts()) {
16    // ...
17  }
18})

Example for filename extension check

Use options.checkFile hook function(fieldname, file, filename, encoding, mimetype) can handle filename check.

1const parse = require('co-busboy')
2const path = require('path')
3
4app.use(async (next) => {
5  const ctx = this
6  const parts = parse(this, {
7    // only allow upload `.jpg` files
8    checkFile: (fieldname, file, filename) => {
9      if (path.extname(filename) !== '.jpg') {
10        var err = new Error('invalid jpg image')
11        err.status = 400
12        return err
13      }
14    }
15  })
16  let part
17  while (part = await parts()) {
18    // ...
19  }
20})

API

parts = parse(stream, [options])

1const parse = require('co-busboy')
2const parts = parse(stream, {
3  autoFields: true
4})

options are passed to busboy. The only additional option is autoFields.

Note: If busboy events partsLimit, filesLimit, fieldsLimit is emitted, will throw an error.

part = await parts()

Await the next part. If autoFields: true, this will always be a file stream. Otherwise, it will be a field as an array.

• Readable Stream

  • fieldname
  • filename
  • transferEncoding or encoding
  • mimeType or mime

• Field[]

  0. fieldname
  1. value
  2. valueTruncated - Boolean
  3. fieldnameTruncated - Boolean

If falsey, then the parser is done.

parts.field{}

If autoFields: true, this object will be populated with key/value pairs.

parts.fields[]

If autoFields: true, this array will be populated with all fields.

License

The MIT License (MIT)

Copyright (c) 2013 Jonathan Ong me@jongleberry.com
Copyright (c) 2015 cojs and other contributors

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.