xprezzo-typeis

Infer the content-type of a request.

$3

This is a Node.js module available through the
npm registry. Installation is done using the
npm install command:

``sh
$ npm install xprezzo-typeis
`

API

`js
var http = require('http')
var typeis = require('xprezzo-typeis')

http.createServer(function (req, res) {
var istext = typeis(req, ['text/*'])
res.end('you ' + (istext ? 'sent' : 'did not send') + ' me text')
})
`

$3

Checks if the request is one of the types. If the request has no body,
even if there is a Content-Type header, then null is returned. If the
Content-Type header is invalid or does not matches any of the types, then
false is returned. Otherwise, a string of the type that matched is returned.

The request argument is expected to be a Node.js HTTP request. The types
argument is an array of type strings.

Each type in the types array can be one of the following:

- A file 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.

Some examples to illustrate the inputs and returned value:

`js
// req.headers.content-type = 'application/json'

typeis(req, ['json']) // => 'json'
typeis(req, ['html', 'json']) // => 'json'
typeis(req, ['application/*']) // => 'application/json'
typeis(req, ['application/json']) // => 'application/json'

typeis(req, ['html']) // => false
`

$3

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.

`js
if (typeis.hasBody(req)) {
// read the body, since there is one

req.on('data', function (chunk) {
// ...
})
}
`

$3

Checks if the mediaType is one of the types. If the mediaType is invalid
or does not matches any of the types, then false is returned. Otherwise, a
string of the type that matched is returned.

The mediaType argument is expected to be a
media type string. The types argument
is an array of type strings.

Each type in the types array can be one of the following:

- A file 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.

Some examples to illustrate the inputs and returned value:

`js
var mediaType = 'application/json'

typeis.is(mediaType, ['json']) // => 'json'
typeis.is(mediaType, ['html', 'json']) // => 'json'
typeis.is(mediaType, ['application/*']) // => 'application/json'
typeis.is(mediaType, ['application/json']) // => 'application/json'

typeis.is(mediaType, ['html']) // => false
`

Examples

$3

`js
var express = require('express')
var typeis = require('xprezzo-typeis')

var app = express()

app.use(function bodyParser (req, res, next) {
if (!typeis.hasBody(req)) {
return next()
}

switch (typeis(req, ['urlencoded', 'json', 'multipart'])) {
case 'urlencoded':
// parse urlencoded body
throw new Error('implement urlencoded body parsing')
case 'json':
// parse json body
throw new Error('implement json body parsing')
case 'multipart':
// parse multipart body
throw new Error('implement multipart body parsing')
default:
// 415 error code
res.statusCode = 415
res.end()
break
}
})
``

People

Xprezzo and related projects are maintained by Cloudgen Wong.

License

MIT