1  /*!
 2   * negotiator
 3   * Copyright(c) 2012 Federico Romero
 4   * Copyright(c) 2012-2014 Isaac Z. Schlueter
 5   * Copyright(c) 2015 Douglas Christopher Wilson
 6   * MIT Licensed
 7   */
 8  
 9  'use strict';
10  
11  var preferredCharsets = require('./lib/charset')
12  var preferredEncodings = require('./lib/encoding')
13  var preferredLanguages = require('./lib/language')
14  var preferredMediaTypes = require('./lib/mediaType')
15  
16  /**
17   * Module exports.
18   * @public
19   */
20  
21  module.exports = Negotiator;
22  module.exports.Negotiator = Negotiator;
23  
24  /**
25   * Create a Negotiator instance from a request.
26   * @param {object} request
27   * @public
28   */
29  
30  function Negotiator(request) {
31    if (!(this instanceof Negotiator)) {
32      return new Negotiator(request);
33    }
34  
35    this.request = request;
36  }
37  
38  Negotiator.prototype.charset = function charset(available) {
39    var set = this.charsets(available);
40    return set && set[0];
41  };
42  
43  Negotiator.prototype.charsets = function charsets(available) {
44    return preferredCharsets(this.request.headers['accept-charset'], available);
45  };
46  
47  Negotiator.prototype.encoding = function encoding(available, opts) {
48    var set = this.encodings(available, opts);
49    return set && set[0];
50  };
51  
52  Negotiator.prototype.encodings = function encodings(available, options) {
53    var opts = options || {};
54    return preferredEncodings(this.request.headers['accept-encoding'], available, opts.preferred);
55  };
56  
57  Negotiator.prototype.language = function language(available) {
58    var set = this.languages(available);
59    return set && set[0];
60  };
61  
62  Negotiator.prototype.languages = function languages(available) {
63    return preferredLanguages(this.request.headers['accept-language'], available);
64  };
65  
66  Negotiator.prototype.mediaType = function mediaType(available) {
67    var set = this.mediaTypes(available);
68    return set && set[0];
69  };
70  
71  Negotiator.prototype.mediaTypes = function mediaTypes(available) {
72    return preferredMediaTypes(this.request.headers.accept, available);
73  };
74  
75  // Backwards compatibility
76  Negotiator.prototype.preferredCharset = Negotiator.prototype.charset;
77  Negotiator.prototype.preferredCharsets = Negotiator.prototype.charsets;
78  Negotiator.prototype.preferredEncoding = Negotiator.prototype.encoding;
79  Negotiator.prototype.preferredEncodings = Negotiator.prototype.encodings;
80  Negotiator.prototype.preferredLanguage = Negotiator.prototype.language;
81  Negotiator.prototype.preferredLanguages = Negotiator.prototype.languages;
82  Negotiator.prototype.preferredMediaType = Negotiator.prototype.mediaType;
83  Negotiator.prototype.preferredMediaTypes = Negotiator.prototype.mediaTypes;