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/*!
* negotiator
* Copyright(c) 2012 Federico Romero
* Copyright(c) 2012-2014 Isaac Z. Schlueter
* Copyright(c) 2015 Douglas Christopher Wilson
* MIT Licensed
*/
'use strict';
/**
* Cached loaded submodules.
* @private
*/
var modules = Object.create(null);
/**
* Module exports.
* @public
*/
module.exports = Negotiator;
module.exports.Negotiator = Negotiator;
/**
* Create a Negotiator instance from a request.
* @param {object} request
* @public
*/
function Negotiator(request) {
if (!(this instanceof Negotiator)) {
return new Negotiator(request);
}
this.request = request;
}
Negotiator.prototype.charset = function charset(available) {
var set = this.charsets(available);
return set && set[0];
};
Negotiator.prototype.charsets = function charsets(available) {
var preferredCharsets = loadModule('charset').preferredCharsets;
return preferredCharsets(this.request.headers['accept-charset'], available);
};
Negotiator.prototype.encoding = function encoding(available) {
var set = this.encodings(available);
return set && set[0];
};
Negotiator.prototype.encodings = function encodings(available) {
var preferredEncodings = loadModule('encoding').preferredEncodings;
return preferredEncodings(this.request.headers['accept-encoding'], available);
};
Negotiator.prototype.language = function language(available) {
var set = this.languages(available);
return set && set[0];
};
Negotiator.prototype.languages = function languages(available) {
var preferredLanguages = loadModule('language').preferredLanguages;
return preferredLanguages(this.request.headers['accept-language'], available);
};
Negotiator.prototype.mediaType = function mediaType(available) {
var set = this.mediaTypes(available);
return set && set[0];
};
Negotiator.prototype.mediaTypes = function mediaTypes(available) {
var preferredMediaTypes = loadModule('mediaType').preferredMediaTypes;
return preferredMediaTypes(this.request.headers.accept, available);
};
// Backwards compatibility
Negotiator.prototype.preferredCharset = Negotiator.prototype.charset;
Negotiator.prototype.preferredCharsets = Negotiator.prototype.charsets;
Negotiator.prototype.preferredEncoding = Negotiator.prototype.encoding;
Negotiator.prototype.preferredEncodings = Negotiator.prototype.encodings;
Negotiator.prototype.preferredLanguage = Negotiator.prototype.language;
Negotiator.prototype.preferredLanguages = Negotiator.prototype.languages;
Negotiator.prototype.preferredMediaType = Negotiator.prototype.mediaType;
Negotiator.prototype.preferredMediaTypes = Negotiator.prototype.mediaTypes;
/**
* Load the given module.
* @private
*/
function loadModule(moduleName) {
var module = modules[moduleName];
if (module !== undefined) {
return module;
}
// This uses a switch for static require analysis
switch (moduleName) {
case 'charset':
module = require('./lib/charset');
break;
case 'encoding':
module = require('./lib/encoding');
break;
case 'language':
module = require('./lib/language');
break;
case 'mediaType':
module = require('./lib/mediaType');
break;
default:
throw new Error('Cannot find module \'' + moduleName + '\'');
}
// Store to prevent invoking require()
modules[moduleName] = module;
return module;
}