source: trip-planner-front/node_modules/component-emitter/index.js@ 76712b2

Last change on this file since 76712b2 was 6a3a178, checked in by Ema <ema_spirova@…>, 3 years ago

initial commit

  • Property mode set to 100644
File size: 3.2 KB
Line 
1
2/**
3 * Expose `Emitter`.
4 */
5
6if (typeof module !== 'undefined') {
7 module.exports = Emitter;
8}
9
10/**
11 * Initialize a new `Emitter`.
12 *
13 * @api public
14 */
15
16function Emitter(obj) {
17 if (obj) return mixin(obj);
18};
19
20/**
21 * Mixin the emitter properties.
22 *
23 * @param {Object} obj
24 * @return {Object}
25 * @api private
26 */
27
28function mixin(obj) {
29 for (var key in Emitter.prototype) {
30 obj[key] = Emitter.prototype[key];
31 }
32 return obj;
33}
34
35/**
36 * Listen on the given `event` with `fn`.
37 *
38 * @param {String} event
39 * @param {Function} fn
40 * @return {Emitter}
41 * @api public
42 */
43
44Emitter.prototype.on =
45Emitter.prototype.addEventListener = function(event, fn){
46 this._callbacks = this._callbacks || {};
47 (this._callbacks['$' + event] = this._callbacks['$' + event] || [])
48 .push(fn);
49 return this;
50};
51
52/**
53 * Adds an `event` listener that will be invoked a single
54 * time then automatically removed.
55 *
56 * @param {String} event
57 * @param {Function} fn
58 * @return {Emitter}
59 * @api public
60 */
61
62Emitter.prototype.once = function(event, fn){
63 function on() {
64 this.off(event, on);
65 fn.apply(this, arguments);
66 }
67
68 on.fn = fn;
69 this.on(event, on);
70 return this;
71};
72
73/**
74 * Remove the given callback for `event` or all
75 * registered callbacks.
76 *
77 * @param {String} event
78 * @param {Function} fn
79 * @return {Emitter}
80 * @api public
81 */
82
83Emitter.prototype.off =
84Emitter.prototype.removeListener =
85Emitter.prototype.removeAllListeners =
86Emitter.prototype.removeEventListener = function(event, fn){
87 this._callbacks = this._callbacks || {};
88
89 // all
90 if (0 == arguments.length) {
91 this._callbacks = {};
92 return this;
93 }
94
95 // specific event
96 var callbacks = this._callbacks['$' + event];
97 if (!callbacks) return this;
98
99 // remove all handlers
100 if (1 == arguments.length) {
101 delete this._callbacks['$' + event];
102 return this;
103 }
104
105 // remove specific handler
106 var cb;
107 for (var i = 0; i < callbacks.length; i++) {
108 cb = callbacks[i];
109 if (cb === fn || cb.fn === fn) {
110 callbacks.splice(i, 1);
111 break;
112 }
113 }
114
115 // Remove event specific arrays for event types that no
116 // one is subscribed for to avoid memory leak.
117 if (callbacks.length === 0) {
118 delete this._callbacks['$' + event];
119 }
120
121 return this;
122};
123
124/**
125 * Emit `event` with the given args.
126 *
127 * @param {String} event
128 * @param {Mixed} ...
129 * @return {Emitter}
130 */
131
132Emitter.prototype.emit = function(event){
133 this._callbacks = this._callbacks || {};
134
135 var args = new Array(arguments.length - 1)
136 , callbacks = this._callbacks['$' + event];
137
138 for (var i = 1; i < arguments.length; i++) {
139 args[i - 1] = arguments[i];
140 }
141
142 if (callbacks) {
143 callbacks = callbacks.slice(0);
144 for (var i = 0, len = callbacks.length; i < len; ++i) {
145 callbacks[i].apply(this, args);
146 }
147 }
148
149 return this;
150};
151
152/**
153 * Return array of callbacks for `event`.
154 *
155 * @param {String} event
156 * @return {Array}
157 * @api public
158 */
159
160Emitter.prototype.listeners = function(event){
161 this._callbacks = this._callbacks || {};
162 return this._callbacks['$' + event] || [];
163};
164
165/**
166 * Check if this emitter has `event` handlers.
167 *
168 * @param {String} event
169 * @return {Boolean}
170 * @api public
171 */
172
173Emitter.prototype.hasListeners = function(event){
174 return !! this.listeners(event).length;
175};
Note: See TracBrowser for help on using the repository browser.