/*!
* accepts
* Copyright(c) 2014 Jonathan Ong
* Copyright(c) 2015 Douglas Christopher Wilson
* MIT Licensed
*/
'use strict'
/**
* Module dependencies.
* @private
*/
var Negotiator = require('negotiator')
var mime = require('mime-types')
/**
* Module exports.
* @public
*/
module.exports = Accepts
/**
* Create a new Accepts object for the given req.
*
* @param {object} req
* @public
*/
function Accepts (req) {
if (!(this instanceof Accepts)) {
return new Accepts(req)
}
this.headers = req.headers
this.negotiator = new Negotiator(req)
}
/**
* Check if the given `type(s)` is acceptable, returning
* the best match when true, otherwise `undefined`, in which
* case you should respond with 406 "Not Acceptable".
*
* The `type` value may be a single mime type string
* such as "application/json", the extension name
* such as "json" or an array `["json", "html", "text/plain"]`. When a list
* or array is given the _best_ match, if any is returned.
*
* Examples:
*
* // Accept: text/html
* this.types('html');
* // => "html"
*
* // Accept: text/*, application/json
* this.types('html');
* // => "html"
* this.types('text/html');
* // => "text/html"
* this.types('json', 'text');
* // => "json"
* this.types('application/json');
* // => "application/json"
*
* // Accept: text/*, application/json
* this.types('image/png');
* this.types('png');
* // => undefined
*
* // Accept: text/*;q=.5, application/json
* this.types(['html', 'json']);
* this.types('html', 'json');
* // => "json"
*
* @param {String|Array} types...
* @return {String|Array|Boolean}
* @public
*/
Accepts.prototype.type =
Accepts.prototype.types = function (types_) {
var types = types_
// support flattened arguments
if (types && !Array.isArray(types)) {
types = new Array(arguments.length)
for (var i = 0; i < types.length; i++) {
types[i] = arguments[i]
}
}
// no types, return all requested types
if (!types || types.length === 0) {
return this.negotiator.mediaTypes()
}
// no accept header, return first given type
if (!this.headers.accept) {
return types[0]
}
var mimes = types.map(extToMime)
var accepts = this.negotiator.mediaTypes(mimes.filter(validMime))
var first = accepts[0]
return first
? types[mimes.indexOf(first)]
: false
}
/**
* Return accepted encodings or best fit based on `encodings`.
*
* Given `Accept-Encoding: gzip, deflate`
* an array sorted by quality is returned:
*
* ['gzip', 'deflate']
*
* @param {String|Array} encodings...
* @return {String|Array}
* @public
*/
Accepts.prototype.encoding =
Accepts.prototype.encodings = function (encodings_) {
var encodings = encodings_
// support flattened arguments
if (encodings && !Array.isArray(encodings)) {
encodings = new Array(arguments.length)
for (var i = 0; i < encodings.length; i++) {
encodings[i] = arguments[i]
}
}
// no encodings, return all requested encodings
if (!encodings || encodings.length === 0) {
return this.negotiator.encodings()
}
return this.negotiator.encodings(encodings)[0] || false
}
/**
* Return accepted charsets or best fit based on `charsets`.
*
* Given `Accept-Charset: utf-8, iso-8859-1;q=0.2, utf-7;q=0.5`
* an array sorted by quality is returned:
*
* ['utf-8', 'utf-7', 'iso-8859-1']
*
* @param {String|Array} charsets...
* @return {String|Array}
* @public
*/
Accepts.prototype.charset =
Accepts.prototype.charsets = function (charsets_) {
var charsets = charsets_
// support flattened arguments
if (charsets && !Array.isArray(charsets)) {
charsets = new Array(arguments.length)
for (var i = 0; i < charsets.length; i++) {
charsets[i] = arguments[i]
}
}
// no charsets, return all requested charsets
if (!charsets || charsets.length === 0) {
return this.negotiator.charsets()
}
return this.negotiator.charsets(charsets)[0] || false
}
/**
* Return accepted languages or best fit based on `langs`.
*
* Given `Accept-Language: en;q=0.8, es, pt`
* an array sorted by quality is returned:
*
* ['es', 'pt', 'en']
*
* @param {String|Array} langs...
* @return {Array|String}
* @public
*/
Accepts.prototype.lang =
Accepts.prototype.langs =
Accepts.prototype.language =
Accepts.prototype.languages = function (languages_) {
var languages = languages_
// support flattened arguments
if (languages && !Array.isArray(languages)) {
languages = new Array(arguments.length)
for (var i = 0; i < languages.length; i++) {
languages[i] = arguments[i]
}
}
// no languages, return all requested languages
if (!languages || languages.length === 0) {
return this.negotiator.languages()
}
return this.negotiator.languages(languages)[0] || false
}
/**
* Convert extnames to mime.
*
* @param {String} type
* @return {String}
* @private
*/
function extToMime (type) {
return type.indexOf('/') === -1
? mime.lookup(type)
: type
}
/**
* Check if mime is valid.
*
* @param {String} type
* @return {String}
* @private
*/
function validMime (type) {
return typeof type === 'string'
}