# body-parser
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Node.js body parsing middleware.
_This does not handle multipart bodies_, due to their complex and typically
large nature. For multipart bodies, you may be interested in the following
modules:
* [busboy](https://www.npmjs.org/package/busboy#readme) and
[connect-busboy](https://www.npmjs.org/package/connect-busboy#readme)
* [multiparty](https://www.npmjs.org/package/multiparty#readme) and
[connect-multiparty](https://www.npmjs.org/package/connect-multiparty#readme)
* [formidable](https://www.npmjs.org/package/formidable#readme)
* [multer](https://www.npmjs.org/package/multer#readme)
This module provides the following parsers:
* [JSON body parser](#bodyparserjsonoptions)
* [Raw body parser](#bodyparserrawoptions)
* [Text body parser](#bodyparsertextoptions)
* [URL-encoded form body parser](#bodyparserurlencodedoptions)
Other body parsers you might be interested in:
- [body](https://www.npmjs.org/package/body#readme)
- [co-body](https://www.npmjs.org/package/co-body#readme)
## Installation
```sh
$ npm install body-parser
```
## API
```js
var bodyParser = require('body-parser')
```
The `bodyParser` object exposes various factories to create middlewares. All
middlewares will populate the `req.body` property with the parsed body or
provide an error to the callback. The various errors are described in the
[errors section](#errors).
### bodyParser.json(options)
Returns middleware that only parses `json`. This parser accepts any Unicode
encoding of the body and supports automatic inflation of `gzip` and `deflate`
encodings.
A new `body` object containing the parsed data is populated on the `request`
object after the middleware (i.e. `req.body`).
#### Options
The `json` function takes an option `options` object that may contain any of
the following keys:
##### inflate
When set to `true`, then deflated (compressed) bodies will be inflated; when
`false`, deflated bodies are rejected. Defaults to `true`.
##### limit
Controls the maximum request body size. If this is a number, then the value
specifies the number of bytes; if it is a string, the value is passed to the
[bytes](https://www.npmjs.com/package/bytes) library for parsing. Defaults
to `'100kb'`.
##### reviver
The `reviver` option is passed directly to `JSON.parse` as the second
argument. You can find more information on this argument
[in the MDN documentation about JSON.parse](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse#Example.3A_Using_the_reviver_parameter).
##### strict
When set to `true`, will only accept arrays and objects; when `false` will
accept anything `JSON.parse` accepts. Defaults to `true`.
##### type
The `type` option is used to determine what media type the middleware will
parse. This option can be a function or a string. If a string, `type` option
is passed directly to the [type-is](https://www.npmjs.org/package/type-is#readme)
library and this can be an extension name (like `json`), a mime type (like
`application/json`), or a mime type with a wildcard (like `*/*` or `*/json`).
If a function, the `type` option is called as `fn(req)` and the request is
parsed if it returns a truthy value. Defaults to `application/json`.
##### verify
The `verify` option, if supplied, is called as `verify(req, res, buf, encoding)`,
where `buf` is a `Buffer` of the raw request body and `encoding` is the
encoding of the request. The parsing can be aborted by throwing an error.
### bodyParser.raw(options)
Returns middleware that parses all bodies as a `Buffer`. This parser
supports automatic inflation of `gzip` and `deflate` encodings.
A new `body` object containing the parsed data is populated on the `request`
object after the middleware (i.e. `req.body`). This will be a `Buffer` object
of the body.
#### Options
The `raw` function takes an option `options` object that may contain any of
the following keys:
##### inflate
When set to `true`, then deflated (compressed) bodies will be inflated; when
`false`, deflated bodies are rejected. Defaults to `true`.
##### limit
Controls the maximum request body size. If this is a number, then the value
specifies the number of bytes; if it is a string, the value is passed to the
[bytes](https://www.npmjs.com/package/bytes) library for parsing. Defaults
to `'100kb'`.
##### type
The `type` option is used to determine what media type the middleware will
parse. This option can be a function or a string. If a string, `type` option
is passed directly to the [type-is](https://www.npmjs.org/package/type-is#readme)
library and this can be an extension name (like `bin`), a mime type (like
`application/octet-stream`), or a mime type with a wildcard (like `*/*` or
`application/*`). If a function, the `type` option is called as `fn(req)`
and the request is parsed if it returns a truthy value. Defaults to
`application/octet-stream`.
##### verify
The `verify` option, if supplied, is called as `verify(req, res, buf, encoding)`,
where `buf` is a `Buffer` of the raw request body and `encoding` is the
encoding of the request. The parsing can be aborted by throwing an error.
### bodyParser.text(options)
Returns middleware that parses all bodies as a string. This parser supports
automatic inflation of `gzip` and `deflate` encodings.
A new `body` string containing the parsed data is populated on the `request`
object after the middleware (i.e. `req.body`). This will be a string of the
body.
#### Options
The `text` function takes an option `options` object that may contain any of
the following keys:
##### defaultCharset
Specify the default character set for the text content if the charset is not
specified in the `Content-Type` header of the request. Defaults to `utf-8`.
##### inflate
When set to `true`, then deflated (compressed) bodies will be inflated; when
`false`, deflated bodies are rejected. Defaults to `true`.
##### limit
Controls the maximum request body size. If this is a number, then the value
specifies the number of bytes; if it is a string, the value is passed to the
[bytes](https://www.npmjs.com/package/bytes) library for parsing. Defaults
to `'100kb'`.
##### type
The `type` option is used to determine what media type the middleware will
parse. This option can be a function or a string. If a string, `type` option
is passed directly to the [type-is](https://www.npmjs.org/package/type-is#readme)
library and this can be an extension name (like `txt`), a mime type (like
`text/plain`), or a mime type with a wildcard (like `*/*` or `text/*`).
If a function, the `type` option is called as `fn(req)` and the request is
parsed if it returns a truthy value. Defaults to `text/plain`.
##### verify
The `verify` option, if supplied, is called as `verify(req, res, buf, encoding)`,
where `buf` is a `Buffer` of the raw request body and `encoding` is the
encoding of the request. The parsing can be aborted by throwing an error.
### bodyParser.urlencoded(options)
Returns middleware that only parses `urlencoded` bodies. This parser accepts
only UTF-8 encoding of the body and supports automatic inflation of `gzip`
and `deflate` encodings.
A new `body` object containing the parsed data is populated on the `request`
object after the middleware (i.e. `req.body`). This object will contain
key-value pairs, where the value can be a string or array (when `extended` is
`false`), or any type (when `extended` is `true`).
#### Options
The `urlencoded` function takes an option `options` object that may contain
any of the following keys:
##### extended
The `extended` option allows to choose between parsing the URL-encoded data
with the `querystring` library (when `false`) or the `qs` library (when
`true`). The "extended" syntax allows for rich objec