opusdev/vector-similarity-api

1/*!2 * accepts3 * Copyright(c) 2014 Jonathan Ong4 * Copyright(c) 2015 Douglas Christopher Wilson5 * MIT Licensed6 */7 8'use strict'9 10/**11 * Module dependencies.12 * @private13 */14 15var Negotiator = require('negotiator')16var mime = require('mime-types')17 18/**19 * Module exports.20 * @public21 */22 23module.exports = Accepts24 25/**26 * Create a new Accepts object for the given req.27 *28 * @param {object} req29 * @public30 */31 32function Accepts (req) {33  if (!(this instanceof Accepts)) {34    return new Accepts(req)35  }36 37  this.headers = req.headers38  this.negotiator = new Negotiator(req)39}40 41/**42 * Check if the given `type(s)` is acceptable, returning43 * the best match when true, otherwise `undefined`, in which44 * case you should respond with 406 "Not Acceptable".45 *46 * The `type` value may be a single mime type string47 * such as "application/json", the extension name48 * such as "json" or an array `["json", "html", "text/plain"]`. When a list49 * or array is given the _best_ match, if any is returned.50 *51 * Examples:52 *53 *     // Accept: text/html54 *     this.types('html');55 *     // => "html"56 *57 *     // Accept: text/*, application/json58 *     this.types('html');59 *     // => "html"60 *     this.types('text/html');61 *     // => "text/html"62 *     this.types('json', 'text');63 *     // => "json"64 *     this.types('application/json');65 *     // => "application/json"66 *67 *     // Accept: text/*, application/json68 *     this.types('image/png');69 *     this.types('png');70 *     // => undefined71 *72 *     // Accept: text/*;q=.5, application/json73 *     this.types(['html', 'json']);74 *     this.types('html', 'json');75 *     // => "json"76 *77 * @param {String|Array} types...78 * @return {String|Array|Boolean}79 * @public80 */81 82Accepts.prototype.type =83Accepts.prototype.types = function (types_) {84  var types = types_85 86  // support flattened arguments87  if (types && !Array.isArray(types)) {88    types = new Array(arguments.length)89    for (var i = 0; i < types.length; i++) {90      types[i] = arguments[i]91    }92  }93 94  // no types, return all requested types95  if (!types || types.length === 0) {96    return this.negotiator.mediaTypes()97  }98 99  // no accept header, return first given type100  if (!this.headers.accept) {101    return types[0]102  }103 104  var mimes = types.map(extToMime)105  var accepts = this.negotiator.mediaTypes(mimes.filter(validMime))106  var first = accepts[0]107 108  return first109    ? types[mimes.indexOf(first)]110    : false111}112 113/**114 * Return accepted encodings or best fit based on `encodings`.115 *116 * Given `Accept-Encoding: gzip, deflate`117 * an array sorted by quality is returned:118 *119 *     ['gzip', 'deflate']120 *121 * @param {String|Array} encodings...122 * @return {String|Array}123 * @public124 */125 126Accepts.prototype.encoding =127Accepts.prototype.encodings = function (encodings_) {128  var encodings = encodings_129 130  // support flattened arguments131  if (encodings && !Array.isArray(encodings)) {132    encodings = new Array(arguments.length)133    for (var i = 0; i < encodings.length; i++) {134      encodings[i] = arguments[i]135    }136  }137 138  // no encodings, return all requested encodings139  if (!encodings || encodings.length === 0) {140    return this.negotiator.encodings()141  }142 143  return this.negotiator.encodings(encodings)[0] || false144}145 146/**147 * Return accepted charsets or best fit based on `charsets`.148 *149 * Given `Accept-Charset: utf-8, iso-8859-1;q=0.2, utf-7;q=0.5`150 * an array sorted by quality is returned:151 *152 *     ['utf-8', 'utf-7', 'iso-8859-1']153 *154 * @param {String|Array} charsets...155 * @return {String|Array}156 * @public157 */158 159Accepts.prototype.charset =160Accepts.prototype.charsets = function (charsets_) {161  var charsets = charsets_162 163  // support flattened arguments164  if (charsets && !Array.isArray(charsets)) {165    charsets = new Array(arguments.length)166    for (var i = 0; i < charsets.length; i++) {167      charsets[i] = arguments[i]168    }169  }170 171  // no charsets, return all requested charsets172  if (!charsets || charsets.length === 0) {173    return this.negotiator.charsets()174  }175 176  return this.negotiator.charsets(charsets)[0] || false177}178 179/**180 * Return accepted languages or best fit based on `langs`.181 *182 * Given `Accept-Language: en;q=0.8, es, pt`183 * an array sorted by quality is returned:184 *185 *     ['es', 'pt', 'en']186 *187 * @param {String|Array} langs...188 * @return {Array|String}189 * @public190 */191 192Accepts.prototype.lang =193Accepts.prototype.langs =194Accepts.prototype.language =195Accepts.prototype.languages = function (languages_) {196  var languages = languages_197 198  // support flattened arguments199  if (languages && !Array.isArray(languages)) {200    languages = new Array(arguments.length)201    for (var i = 0; i < languages.length; i++) {202      languages[i] = arguments[i]203    }204  }205 206  // no languages, return all requested languages207  if (!languages || languages.length === 0) {208    return this.negotiator.languages()209  }210 211  return this.negotiator.languages(languages)[0] || false212}213 214/**215 * Convert extnames to mime.216 *217 * @param {String} type218 * @return {String}219 * @private220 */221 222function extToMime (type) {223  return type.indexOf('/') === -1224    ? mime.lookup(type)225    : type226}227 228/**229 * Check if mime is valid.230 *231 * @param {String} type232 * @return {String}233 * @private234 */235 236function validMime (type) {237  return typeof type === 'string'238}239