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