1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<link rel="shortcut icon" href="favicon.ico" >
<meta property="fb:page_id" content="316663535020759" />
<meta name="title" content="Arbiter.js - A full-featured javascript pub/sub (Observer) implementation" />
<meta name="description" content="Arbiter.js is a light-weight, library-agnostic javascript implementation of the pub/sub pattern, written by Matt Kruse. It allows objects on your page to be de-coupled, and communicate with each other through messages. This leads to a cleaner, more easily understood design, and easier maintenance. " />
<link rel="image_src" type="image/gif" href="fb_share.gif" />
<meta property="og:image" content="http://arbiterjs.com/fb_share.gif"/>
<title>Arbiter.js - A full-featured javascript pub/sub (Observer) implementation by Matt Kruse</title>
<script src="jquery.js"></script>
<script src="Arbiter.js"></script>
<script>
$(function() {
$('#version').html( Arbiter.version );
$('#updated_on').html( Arbiter.updated_on );
});
</script>
<style>
* {
font-family:verdana,arial,sans-serif;
}
#wrapper {
width:850px;
text-align:left;
}
#license {
font-size:smaller;
font-style:italic;
}
.section {
margin-top:20px;
}
.section .title {
background-color:#669;
color:white;
padding:5px;
font-size:20px;
font-weight:bold;
border-radius:5px;
-moz-border-radius:5px;
-webkit-border-radius:5px;
}
.download_wrapper {
float:right;
width:250px;
padding:20px 0 20px 20px;
background-color:white;
}
.download {
border:2px solid #343499;
border-radius:5px;
-moz-border-radius:5px;
-webkit-border-radius:5px;
background-color:#CACAFC;
padding:5px;
}
.source {
margin-top:20px;
border:1px solid #ccc;
background-color:#eee;
padding:3px;
}
.code, .code * {
white-space:pre;
font-family:courier new;
font-size:12px;
overflow:auto;
}
.comment {
color:#999;
}
.doc-title {
font-weight:bold;
font-size:18px;
margin:20px 0;
}
.doc-definition {
margin-left:20px;
font-style:italic;
}
.doc-returns {
margin-left:20px;
font-size:smaller;
font-style:italic;
}
.doc-example {
border:1px solid #ccc;
background-color:#eee;
padding:3px;
margin:5px 0;
}
</style>
</head>
<body>
<center>
<div id="wrapper">
<div class="header">
<img src="logo.gif">
</div>
<div class="download_wrapper">
<div class="download">
Download source:
<a href="Arbiter.js">Arbiter.js</a><br>
Version: <span id="version"></span><br>
Updated: <span id="updated_on"></span><br>
<span id="license">This work is in the public domain and may be used in any way, for any purpose, without restriction.</span>
</div>
<br>
Support:<br>
<iframe src="//www.facebook.com/plugins/likebox.php?href=https%3A%2F%2Fwww.facebook.com%2Fpages%2FArbiterjs%2F316663535020759&width=210&height=62&colorscheme=light&show_faces=false&border_color&stream=false&header=false" scrolling="no" frameborder="0" style="border:none; overflow:hidden; width:210px; height:62px;" allowTransparency="true"></iframe> </div>
<div class="section">
<div class="body">
<p>
<a href="https://www.google.com/search?q=define%3Aarbiter" target="_blank">Arbiter</a>.js is a light-weight, library-agnostic javascript implementation of the <a href="http://en.wikipedia.org/wiki/Publish%E2%80%93subscribe_pattern" target="_blank">pub/sub pattern</a>, written by <a href="http://MattKruse.com" target="_blank">Matt Kruse</a>. It allows objects on your page to be de-coupled, and communicate with each other through messages. This leads to a cleaner, more easily understood design, and easier maintenance.
</p>
<center><img src="example.gif"></center>
<p>
For example, if the user changes a value on one part of the page, it can publish a message saying which action was taken. Other parts of the page can subscribe to that action, and do something when it happens. But the first interaction doesn't have to know anything about the second. It just announces what happened, and anyone who cares can act on it.
</p>
</div>
</div>
<div class="section">
<div class="title">Example</div>
<div class="body">
<p>A simple code example might look like this:</p>
<div class="code">
// In the "notifications" widget, I want to do something when new mail arrives
Arbiter.subscribe("email/new", function(data) {
document.getElementById('notification').innerHTML = "New email from "+data.from;
});
// This code is called by the system that detects incoming email
Arbiter.publish("email/new", {from:"Bob"});
</div>
<div id="console" style="font-size:10px;max-height:125px;overflow-y:auto;background-color:#ffffcc;border:2px solid #666; padding:3px;margin:5px;min-height:100px;float:right;width:600px;">
<b>Console:</b><br>
Arbiter.subscribe('click/*', null, document.getElementById('console'), function(data,msg) {
this.innerHTML += msg+"<br>";
});
<hr>
</div>
<p>Here is a simple working example:</p>
<script type="text/javascript">
Arbiter.subscribe('click/*', null, document.getElementById('console'), function(data,msg) {
this.innerHTML += msg+"<br>";
});
</script>
<button onclick="Arbiter.publish('click/1')">Arbiter.publish('click/1')</button><br>
<button onclick="Arbiter.publish('click/2')">Arbiter.publish('click/2')</button><br>
<button onclick="Arbiter.publish('click/3')">Arbiter.publish('click/3')</button><br>
<br style="clear:both;">
</div>
</div>
<div class="section">
<div class="title">Method Summary</div>
<div class="body">
<div class="doc-title">Arbiter.publish</div>
<div class="code">Arbiter.publish( msg [, data [, options] ] )
Returns: true on success, false if any subscriber has thrown a js exception
</div>
<div class="doc-title">Arbiter.subscribe</div>
<div class="code">Arbiter.subscribe( msg, func )
Arbiter.subscribe( msg, options, func )
Arbiter.subscribe( msg, options, context, func )
Returns: subscription id
or [id1,id2] if subscribing to multiple messages
</div>
<div class="doc-title">Arbiter.unsubscribe</div>
<div class="code">Arbiter.unsubscribe( subscription_id )</div>
<div class="doc-title">Arbiter.resubscribe</div>
<div class="code">Arbiter.resubscribe( subscription_id )</div>
<div class="doc-title">Arbiter.create</div>
<div class="code">Arbiter.create()</div>
</div>
</div>
<div class="section">
<div class="title">How To</div>
<div class="body">
<div class="doc-section">
<div class="doc-title">Publish a simple message</div>
<div class="doc-example code">Arbiter.publish( 'component/msg' );</div>
<div class="doc-desc">A message may be in any format, but may not contain [ ,*]. A structure like a/b/c is recommended by convention, to allow messages to be categorized.
</div>
<div class="doc-section">
<div class="doc-title">Subscribe to a message</div>
<div class="doc-example code">Arbiter.subscribe( 'component/msg', function() { } );</div>
<div class="doc-desc">Subscriber functions will be passed the following arguments:
<ul>
<li>published_data: Any data that the publisher has passed along
<li>message: The message text that triggered the notification (useful if a subscriber function can handle multiple messages)
<li>subscriber_data: An object (initially empty) that will be passed between subscribers. This may be useful if you would like subscribers to send context or additional data to subsequent subscribers
</ul>
The value of "this" to be used within the function may be set in the subscribe() method itself.
</div>
</div>
<div class="doc-section">
<div class="doc-title">Pass data to subscribers</div>
<div class="doc-example code">Arbiter.publish( 'component/msg', {"data":"value"} );</div>
<div class="doc-desc">Publishers can pass data to subscribers that contains details about the message.</div>
</div>
<div class="doc-section">
<div class="doc-title">Force message bubbling</div>
<div class="doc-example code">Arbiter.publish( 'component/msg' , null, {cancelable:false} );</div>
<div class="doc-desc">By default, subscribers can return "false" to prevent subsequent subscribers from receiving the message. By passing cancelable:false in the options, the publisher can prevent canceling.</div>
</div>
<div class="doc-section">
<div class="doc-title">Allow late susbcribers to be notified of past messages</div>
<div class="doc-example code">Arbiter.publish( 'component/msg' , null, {persist:true} );</div>
<div class="doc-desc">By default, subscribers only receive notifications about messages sent after they subscribe. But for some events, like "system initalized" that may fire only once, it can be useful to allow subscribers to that message to get fired if the message has already been sent. If the publishers wants subscribers to be notified of this message even if they subscribe later, setting the persist flag will do that.</div>
</div>
<div class="doc-section">
<div class="doc-title">Fire subscribers asynchronously</div>
<div class="doc-example code">Arbiter.publish( 'component/msg', null, {async:true} );</div>
<div class="doc-desc">By default, subscribers are notified and their functions are run synchronously, so the publish() function doesn't return until all subscribers have finished. If you wish to notify the subscribers but return from the publish() call before the subscriber functions execute, use asynchronous mode. <b>Note:</b> Subscribers cannot cancel asynchonous messages, because the subscribers are executed independently using setTimeout()</div>
</div>
<div class="doc-section">
<div class="doc-title">Subscribe to multiple messages at once</div>
<div class="doc-example code">Arbiter.subscribe( 'component/msg, component/msg2', function() { } );
or
Arbiter.subscribe( ['component/msg','component/msg2'], function() { } );
</div>
<div class="doc-desc">The second argument to the subscriber function is the message, so you can distinguish which messages you are handling.</div>
</div>
<div class="doc-section">
<div class="doc-title">Subscribe to multiple messages using a wildcard</div>
<div class="doc-example code">Arbiter.subscribe( 'component/*', function() { } );</div>
<div class="doc-desc">This can be useful for handling all messages of a certain component or category. If you take care when naming your messages, using wildcards can help avoid subscribing to multiple individual messages and needing to update as new messages are added.</div>
</div>
<div class="doc-section">
<div class="doc-title">Subscribe to ALL messages</div>
<div class="doc-example code">Arbiter.subscribe( '*', function() { } );</div>
<div class="doc-desc">This can be useful for logging, for example. You can create a separate message logger that receives all messages and displays them in a debug window.</div>
</div>
<div class="doc-section">
<div class="doc-title">Set subscriber priority</div>
<div class="doc-example code">Arbiter.subscribe( 'msg', {priority:10}, func(){} );
Arbiter.subscribe( 'msg', {priority:20}, func(){} ); // Called first!
</div>
<div class="doc-desc">By default, all subscribers have a priority of 0. Higher values get higher priority and are executed first. Negative values are allowed.</div>
</div>
<div class="doc-section">
<div class="doc-title">Execute a subscriber asynchronously</div>
<div class="doc-example code">Arbiter.subscribe( 'msg', {async:true}, func(){} );</div>
<div class="doc-desc">A subscriber can be set to execute asynchronously, even if the message wasn't published as async. If a subscriber knows that it will do some heavy calculations, for example, it can force itself to be async so it won't interfere with the execution of other subscribers.</div>
</div>
<div class="doc-section">
<div class="doc-title">Ignore persisted messages</div>
<div class="doc-example code">Arbiter.subscribe( 'msg', {persist:false}, func(){} );</div>
<div class="doc-desc">If a message was persisted, a subscriber will be notified of it even if was sent in the past. If your subscriber is not interested in any past messages that may have been persisted, you can force them to be ignored.</div>
</div>
<div class="doc-section">
<div class="doc-title">Set the value of "this"</div>
<div class="doc-example code">Arbiter.subscribe( 'msg', null, document.getElementById('x'),
function() {
this.innerHTML = "Message handled!";
}
);
</div>
<div class="doc-desc">When executing the subscriber function, the value of "this" in the function can be specified at subscription time.</div>
</div>
<div class="doc-section">
<div class="doc-title">Unsubscribe from messages</div>
<div class="doc-example code">var subscription_id = Arbiter.subscribe( 'msg', function(){} );
Arbiter.unsubscribe( subscription_id );
</div>
<div class="doc-desc">Unsubscribing simply sets a flag which prevents the subscriber from executing, in case you want to re-subscribe later.</div>
</div>
<div class="doc-section">
<div class="doc-title">Re-subscribe to messages</div>
<div class="doc-example code">var subscription_id = Arbiter.subscribe( 'msg', function(){} );
Arbiter.unsubscribe( subscription_id );
Arbiter.resubscribe( subscription_id );
</div>
<div class="doc-desc">After unsubscribing, you can later re-subscribe to begin receiving messages again</div>
</div>
<div class="doc-section">
<div class="doc-title">Create a new message handler</div>
<div class="doc-example code">var MyController = Arbiter.create()</div>
<div class="doc-desc">This creates a separate Arbiter instance. If you want to have different message handlers entirely, for example, this will allow for that. Messages sent to the new object will not be shared with the default Arbiter object. You may create as many arbiters as you wish, and they will all operate independently.</div>
</div>
</div>
</div>
<div class="section">
<div class="title">Source</div>
<div class="body code source">
/*
Arbiter.js
by Matt Kruse
http://ArbiterJS.com - See site for documentation
This work is in the public domain and may be used in any way, for any purpose, without restriction.
*/
var Arbiter = (function () {
var create_arbiter = function () {
var subscriptions = {};
var wildcard_subscriptions = {};
var persistent_messages = {};
var id_lookup = {};
var new_id = 1;
return {
'version':'1.0'
,'updated_on':'2011-12-19'
,'create': function() { return create_arbiter(); }
,'subscribe': function() {
var msg, messages, subscription_list, persisted_subscription_list, subscription, func, options={}, context, wildcard=false, priority=0, id, return_ids=[];
if (arguments.length<2) { return null; }
messages = arguments[0];
func = arguments[arguments.length-1];<span class="comment"> // Function is always last argument</span>
if (arguments.length>2) { options = arguments[1] || {}; }
if (arguments.length>3) { context = arguments[2]; }
if (options.priority) {
priority = options.priority;
}
if (typeof messages=="string") {
messages = messages.split(/[,\s]+/);
}
for (var i=0; i<messages.length; i++) {
msg = messages[i];
<span class="comment"> // If the message ends in *, it's a wildcard subscription</span>
if (/\*$/.test(msg)) {
wildcard = true;
msg = msg.replace(/\*$/,'');
subscription_list = wildcard_subscriptions[msg];
if (!subscription_list) {
wildcard_subscriptions[msg] = subscription_list = [];
}
}
else {
subscription_list = subscriptions[msg];
if (!subscription_list) {
subscriptions[msg] = subscription_list = [];
}
}
id = new_id++;
subscription = {'id':id,'f':func,p:priority,self:context,'options':options};
id_lookup[id] = subscription;
subscription_list.push ( subscription );
<span class="comment"> // Sort the list by priority</span>
subscription_list = subscription_list.sort( function(a,b) {
return (a.p>b.p?-1:a.p==b.p?0:1);
} );
<span class="comment"> // Put it back in after sorting</span>
if (wildcard) {
wildcard_subscriptions[msg] = subscription_list;
}
else {
subscriptions[msg] = subscription_list;
}
return_ids.push(id);
<span class="comment"> // Check to see if there are any persistent messages that need</span>
<span class="comment"> // to be fired immediately</span>
if (!options.persist && persistent_messages[msg]) {
persisted_subscription_list = persistent_messages[msg];
for (var j=0; j<persisted_subscription_list.length; j++) {
subscription.f.call( subscription.self, persisted_subscription_list[j], {persist:true} );
}
}
}
<span class="comment"> // Return an array of id's, or just 1</span>
if (messages.length>0) {
return return_ids;
}
return return_ids[0];
}
,'publish': function(msg, data, options) {
var async_timeout=10,result,overall_result=true,cancelable=true,internal_data={},subscriber, wildcard_msg;
var subscription_list = subscriptions[msg] || [];
options = options || {};
<span class="comment"> // Look through wildcard subscriptions to find any that apply</span>
for (wildcard_msg in wildcard_subscriptions) {
if (msg.indexOf(wildcard_msg)==0) {
subscription_list = subscription_list.concat( wildcard_subscriptions[wildcard_msg] );
}
}
if (options.persist===true) {
if (!persistent_messages[msg]) {
persistent_messages[msg] = [];
}
persistent_messages[msg].push( data );
}
if (subscription_list.length==0) {
return overall_result;
}
if (typeof options.cancelable=="boolean") {
cancelable = options.cancelable;
}
for (var i=0; i<subscription_list.length; i++) {
subscriber = subscription_list[i];
if (subscriber.unsubscribed) {
continue;<span class="comment"> // Ignore unsubscribed listeners</span>
}
try {
<span class="comment"> // Publisher OR subscriber may request async</span>
if (options.async===true || (subscriber.options && subscriber.options.async)) {
setTimeout( (function(inner_subscriber) {
return function() {
inner_subscriber.f.call( inner_subscriber.self, data, msg, internal_data );
};
})(subscriber), async_timeout++ );
}
else {
result = subscriber.f.call( subscriber.self, data, msg, internal_data );
if (cancelable && result===false) {
break;
}
}
}
catch(e) {
overall_result = false;
}
}
return overall_result;
}
,'unsubscribe': function(id) {
if (id_lookup[id]) {
id_lookup[id].unsubscribed = true;
return true;
}
return false;
}
,'resubscribe': function(id) {
if (id_lookup[id]) {
id_lookup[id].unsubscribed = false;
return true;
}
return false;
}
};
};
return create_arbiter();
})();
</div>
</div>
</div>
</center>
</body>
</html>
|
