@adico/body-parser
v2.0.1
Published
Node.js body parsing middleware
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body-parser
Node.js body parsing middleware.
Parse incoming request bodies in a middleware before your handlers, available
under the req.body
property.
Note As req.body
's shape is based on user-controlled input, all
properties and values in this object are untrusted and should be validated
before trusting. For example, req.body.foo.toString()
may fail in multiple
ways, for example the foo
property may not be there or may not be a string,
and toString
may not be a function and instead a string or other user input.
Learn about the anatomy of an HTTP transaction in Node.js.
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-parser
API
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 when
the Content-Type
request header matches the type
option.
The various errors returned by this module are described in the errors section.
bodyParser.json([options])
Returns middleware that only parses json
and only looks at requests where
the Content-Type
header matches the type
option. This parser accepts any
Unicode encoding of the body and supports automatic inflation of gzip
,
br
(brotli) 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 optional 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 string, array of strings, or a function. If not a
function, 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 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
and only looks at
requests where the Content-Type
header matches the type
option. This
parser supports automatic inflation of gzip
, br
(brotli) 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 optional 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 string, array of strings, or a function.
If not a function, 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 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 and only looks at
requests where the Content-Type
header matches the type
option. This
parser supports automatic inflation of gzip
, br
(brotli) 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 optional 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 string, array of strings, or a function. If not
a function, 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
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 and only looks at
requests where the Content-Type
header matches the type
option. This
parser accepts only UTF-8 encoding of the body and supports automatic
inflation of gzip
, br
(brotli) 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 optional options
object that may contain
any of the following keys:
extended
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 false
.
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 string, array of strings, or a function. If not
a function, 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 type 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 application/x-www-form-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.
defaultCharset
The default charset to parse as, if not specified in content-type. Must be
either utf-8
or iso-8859-1
. Defaults to utf-8
.
charsetSentinel
Whether to let the value of the utf8
parameter take precedence as the charset
selector. It requires the form to contain a parameter named utf8
with a value
of ✓
. Defaults to false
.
interpretNumericEntities
Whether to decode numeric entities such as ☺
when parsing an iso-8859-1
form. Defaults to false
.
depth
The depth
option is used to configure the maximum depth of the qs
library when extended
is true
. This allows you to limit the amount of keys that are parsed and can be useful to prevent certain types of abuse. Defaults to 32
. It is recommended to keep this value as low as possible.
Errors
The middlewares provided by this module create errors using the
http-errors
module. The errors
will typically have a status
/statusCode
property that contains the suggested
HTTP response code, an expose
property to determine if the message
property
should be displayed to the client, a type
property to determine the type of
error without matching against the message
, and a body
property containing
the read body, if available.
The following are the common errors created, though any error can come through for various reasons.
content encoding unsupported
This error will occur when the request had a Content-Encoding
header that
contained an encoding but the "inflation" option was set to false
. The
status
property is set to 415
, the type
property is set to
'encoding.unsupported'
, and the charset
property will be set to the
encoding that is unsupported.
entity parse failed
This error will occur when the request contained an entity that could not be
parsed by the middleware. The status
property is set to 400
, the type
property is set to 'entity.parse.failed'
, and the body
property is set to
the entity value that failed parsing.
entity verify failed
This error will occur when the request contained an entity that could not be
failed verification by the defined verify
option. The status
property is
set to 403
, the type
property is set to 'entity.verify.failed'
, and the
body
property is set to the entity value that failed verification.
request aborted
This error will occur when the request is aborted by the client before reading
the body has finished. The received
property will be set to the number of
bytes received before the request was aborted and the expected
property is
set to the number of expected bytes. The status
property is set to 400
and type
property is set to 'request.aborted'
.
request entity too large
This error will occur when the request body's size is larger than the "limit"
option. The limit
property will be set to the byte limit and the length
property will be set to the request body's length. The status
property is
set to 413
and the type
property is set to 'entity.too.large'
.
request size did not match content length
This error will occur when the request's length did not match the length from
the Content-Length
header. This typically occurs when the request is malformed,
typically when the Content-Length
header was calculated based on characters
instead of bytes. The status
property is set to 400
and the type
property
is set to 'request.size.invalid'
.
stream encoding should not be set
This error will occur when something called the req.setEncoding
method prior
to this middleware. This module operates directly on bytes only and you cannot
call req.setEncoding
when using this module. The status
property is set to
500
and the type
property is set to 'stream.encoding.set'
.
stream is not readable
This error will occur when the request is no longer readable when this middleware
attempts to read it. This typically means something other than a middleware from
this module read the request body already and the middleware was also configured to
read the same request. The status
property is set to 500
and the type
property is set to 'stream.not.readable'
.
too many parameters
This error will occur when the content of the request exceeds the configured
parameterLimit
for the urlencoded
parser. The status
property is set to
413
and the type
property is set to 'parameters.too.many'
.
unsupported charset "BOGUS"
This error will occur when the request had a charset parameter in the
Content-Type
header, but the iconv-lite
module does not support it OR the
parser does not support it. The charset is contained in the message as well
as in the charset
property. The status
property is set to 415
, the
type
property is set to 'charset.unsupported'
, and the charset
property
is set to the charset that is unsupported.
unsupported content encoding "bogus"
This error will occur when the request had a Content-Encoding
header that
contained an unsupported encoding. The encoding is contained in the message
as well as in the encoding
property. The status
property is set to 415
,
the type
property is set to 'encoding.unsupported'
, and the encoding
property is set to the encoding that is unsupported.
The input exceeded the depth
This error occurs when using bodyParser.urlencoded
with the extended
property set to true
and the input exceeds the configured depth
option. The status
property is set to 400
. It is recommended to review the depth
option and evaluate if it requires a higher value. When the depth
option is set to 32
(default value), the error will not be thrown.
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())
// 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(String(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 recommended 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()
// POST /login gets urlencoded bodies
app.post('/login', urlencodedParser, function (req, res) {
if (!req.body || !req.body.username) 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) res.sendStatus(400)
// create user in req.body
})
Change accepted type for parsers
All the parsers accept a type
option which allows you to change the
Content-Type
that the middleware will parse.
var express = require('express')
var bodyParser = require('body-parser')
var app = express()
// 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' }))