type-is
Infer the content-type of a request.
Install
This is a Node.js module available through the
npm registry. Installation is done using the
npm install
command:
$ npm install type-is
API
var http = require('http')
var typeis = require('type-is')
http.createServer(function (req, res) {
var istext = typeis(req, ['text/*'])
res.end('you ' + (istext ? 'sent' : 'did not send') + ' me text')
})
type = typeis(request, types)
request
is the node HTTP request. types
is an array of types.
typeis(req, ['json'])
typeis(req, ['html', 'json'])
typeis(req, ['application/*'])
typeis(req, ['application/json'])
typeis(req, ['html'])
typeis.hasBody(request)
Returns a Boolean if the given request
has a body, regardless of the
Content-Type
header.
Having a body has no relation to how large the body is (it may be 0 bytes).
This is similar to how file existence works. If a body does exist, then this
indicates that there is data to read from the Node.js request stream.
if (typeis.hasBody(req)) {
req.on('data', function (chunk) {
})
}
type = typeis.is(mediaType, types)
mediaType
is the media type string. types
is an array of types.
var mediaType = 'application/json'
typeis.is(mediaType, ['json'])
typeis.is(mediaType, ['html', 'json'])
typeis.is(mediaType, ['application/*'])
typeis.is(mediaType, ['application/json'])
typeis.is(mediaType, ['html'])
Each type can be:
- An extension name such as
json
. This name will be returned if matched. - A mime type such as
application/json
. - A mime type with a wildcard such as
*/*
or */json
or application/*
. The full mime type will be returned if matched. - A suffix such as
+json
. This can be combined with a wildcard such as */vnd+json
or application/*+json
. The full mime type will be returned if matched.
false
will be returned if no type matches or the content type is invalid.
null
will be returned if the request does not have a body.
Examples
Example body parser
var express = require('express')
var typeis = require('type-is')
var app = express()
app.use(function bodyParser (req, res, next) {
if (!typeis.hasBody(req)) {
return next()
}
switch (typeis(req, ['urlencoded', 'json', 'multipart'])) {
case 'urlencoded':
throw new Error('implement urlencoded body parsing')
case 'json':
throw new Error('implement json body parsing')
case 'multipart':
throw new Error('implement multipart body parsing')
default:
res.statusCode = 415
res.end()
break
}
})
License
MIT