body-parser
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:
This module provides the following parsers:
Other body parsers you might be interested in:
Installation
$ npm install body-parserAPI
var bodyParser = require('body-parser')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 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.
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
library and this can be an extension name (like json), a mime type (like
application/json), or a mime time 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 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 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
library and this can be an extension name (like bin), a mime type (like
application/octet-stream), or a mime time 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 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
library and this can be an extension name (like txt), a mime type (like
text/plain), or a mime time 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 objects and arrays to be
encoded into the URL-encoded format, allowing for a JSON-like experience
with URL-encoded. For more information, please
see the qs library.
Defaults to true, but using the default has been deprecated. Please
research into the difference between qs and querystring and choose the
appropriate setting.
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 library for parsing. Defaults
to '100kb'.
parameterLimit
The parameterLimit option controls the maximum number of parameters that
are allowed in the URL-encoded data. If a request contains more parameters
than this value, a 413 will be returned to the client. Defaults to 1000.
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
library and this can be an extension name (like urlencoded), a mime type (like
application/x-www-form-urlencoded), or a mime time with a wildcard (like
*/x-www-form-urlencoded). If a function, the type option is called as
fn(req) and the request is parsed if it returns a truthy value. Defaults
to urlencoded.
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.
Examples
express/connect top-level generic
This example demonstrates adding a generic JSON and URL-encoded parser as a top-level middleware, which will parse the bodies of all incoming requests. This is the simplest setup.
var express = require('express')
var bodyParser = require('body-parser')
var app = express()
// parse application/x-www-form-urlencoded
app.use(bodyParser.urlencoded({ extended: false }))
// parse application/json
app.use(bodyParser.json())
app.use(function (req, res) {
res.setHeader('Content-Type', 'text/plain')
res.write('you posted:\n')
res.end(JSON.stringify(req.body, null, 2))
})express route-specific
This example demonstrates adding body parsers specifically to the routes that need them. In general, this is the most recommend way to use body-parser with express.
var express = require('express')
var bodyParser = require('body-parser')
var app = express()
// create application/json parser
var jsonParser = bodyParser.json()
// create application/x-www-form-urlencoded parser
var urlencodedParser = bodyParser.urlencoded({ extended: false })
// POST /login gets urlencoded bodies
app.post('/login', urlencodedParser, function (req, res) {
if (!req.body) return res.sendStatus(400)
res.send('welcome, ' + req.body.username)
})
// POST /api/users gets JSON bodies
app.post('/api/users', jsonParser, function (req, res) {
if (!req.body) return res.sendStatus(400)
// create user in req.body
})change content-type for parsers
All the parsers accept a type option which allows you to change the
Content-Type that the middleware will parse.
// parse various different custom JSON types as JSON
app.use(bodyParser.json({ type: 'application/*+json' }))
// parse some custom thing into a Buffer
app.use(bodyParser.raw({ type: 'application/vnd.custom-type' }))
// parse an HTML body into a string
app.use(bodyParser.text({ type: 'text/html' }))