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
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
|
/**
* Copyright 2008 Mort Bay Consulting Pty. Ltd.
* Dual licensed under the Apache License 2.0 and the MIT license.
* ----------------------------------------------------------------------------
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http: *www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* ----------------------------------------------------------------------------
* Licensed under the MIT license;
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
* ----------------------------------------------------------------------------
* $Revision$ $Date$
*/
(function($)
{
/**
* The constructor for a Comet object.
* There is a default Comet instance already created at the variable <code>$.cometd</code>,
* and hence that can be used to start a comet conversation with a server.
* In the rare case a page needs more than one comet conversation, a new instance can be
* created via:
* <pre>
* var url2 = ...;
* var cometd2 = new $.Cometd();
* cometd2.init(url2);
* </pre>
*/
$.Cometd = function(name)
{
var _name = name || 'default';
var _logPriorities = { debug: 1, info: 2, warn: 3, error: 4 };
var _logLevel = 'info';
var _url;
var _xd = false;
var _transport;
var _status = 'disconnected';
var _messageId = 0;
var _clientId = null;
var _batch = 0;
var _messageQueue = [];
var _listeners = {};
var _backoff = 0;
var _backoffIncrement = 1000;
var _maxBackoff = 60000;
var _scheduledSend = null;
var _extensions = [];
var _advice = {};
var _handshakeProps;
/**
* Returns the name assigned to this Comet object, or the string 'default'
* if no name has been explicitely passed as parameter to the constructor.
*/
this.getName = function()
{
return _name;
};
/**
* Configures the initial comet communication with the comet server.
* @param cometURL the URL of the comet server
*/
this.configure = function(cometURL)
{
_configure(cometURL);
};
function _configure(cometURL)
{
_url = cometURL;
_debug('Initializing comet with url: {}', _url);
// Check immediately if we're cross domain
// If cross domain, the handshake must not send the long polling transport type
var urlParts = /(^https?:)?(\/\/(([^:\/\?#]+)(:(\d+))?))?([^\?#]*)/.exec(cometURL);
if (urlParts[3]) _xd = urlParts[3] != location.host;
// Temporary setup a transport to send the initial handshake
// The transport may be changed as a result of handshake
if (_xd)
_transport = newCallbackPollingTransport();
else
_transport = newLongPollingTransport();
_debug('Initial transport is {}', _transport.getType());
};
/**
* Configures and establishes the comet communication with the comet server
* via a handshake and a subsequent connect.
* @param cometURL the URL of the comet server
* @param handshakeProps an object to be merged with the handshake message
* @see #configure(cometURL)
* @see #handshake(handshakeProps)
*/
this.init = function(cometURL, handshakeProps)
{
_configure(cometURL);
_handshake(handshakeProps);
};
/**
* Establishes the comet communication with the comet server
* via a handshake and a subsequent connect.
* @param handshakeProps an object to be merged with the handshake message
*/
this.handshake = function(handshakeProps)
{
_handshake(handshakeProps);
};
/**
* Disconnects from the comet server.
* @param disconnectProps an object to be merged with the disconnect message
*/
this.disconnect = function(disconnectProps)
{
var bayeuxMessage = {
channel: '/meta/disconnect'
};
var message = $.extend({}, disconnectProps, bayeuxMessage);
// Deliver immediately
// The handshake and connect mechanism make use of startBatch(), and in case
// of a failed handshake the disconnect would not be delivered if using _send().
_setStatus('disconnecting');
_deliver([message], false);
};
/**
* Marks the start of a batch of application messages to be sent to the server
* in a single request, obtaining a single response containing (possibly) many
* application reply messages.
* Messages are held in a queue and not sent until {@link #endBatch()} is called.
* If startBatch() is called multiple times, then an equal number of endBatch()
* calls must be made to close and send the batch of messages.
* @see #endBatch()
*/
this.startBatch = function()
{
_startBatch();
};
/**
* Marks the end of a batch of application messages to be sent to the server
* in a single request.
* @see #startBatch()
*/
this.endBatch = function()
{
_endBatch(true);
};
/**
* Subscribes to the given channel, performing the given callback in the given scope
* when a message for the channel arrives.
* @param channel the channel to subscribe to
* @param scope the scope of the callback
* @param callback the callback to call when a message is delivered to the channel
* @param subscribeProps an object to be merged with the subscribe message
* @return the subscription handle to be passed to {@link #unsubscribe(object)}
*/
this.subscribe = function(channel, scope, callback, subscribeProps)
{
var subscription = this.addListener(channel, scope, callback);
// Send the subscription message after the subscription registration to avoid
// races where the server would deliver a message to the subscribers, but here
// on the client the subscription has not been added yet to the data structures
var bayeuxMessage = {
channel: '/meta/subscribe',
subscription: channel
};
var message = $.extend({}, subscribeProps, bayeuxMessage);
_send(message);
return subscription;
};
/**
* Unsubscribes the subscription obtained with a call to {@link #subscribe(string, object, function)}.
* @param subscription the subscription to unsubscribe.
*/
this.unsubscribe = function(subscription, unsubscribeProps)
{
// Remove the local listener before sending the message
// This ensures that if the server fails, this client does not get notifications
this.removeListener(subscription);
var bayeuxMessage = {
channel: '/meta/unsubscribe',
subscription: subscription[0]
};
var message = $.extend({}, unsubscribeProps, bayeuxMessage);
_send(message);
};
/**
* Publishes a message on the given channel, containing the given content.
* @param channel the channel to publish the message to
* @param content the content of the message
* @param publishProps an object to be merged with the publish message
*/
this.publish = function(channel, content, publishProps)
{
var bayeuxMessage = {
channel: channel,
data: content
};
var message = $.extend({}, publishProps, bayeuxMessage);
_send(message);
};
/**
* Adds a listener for bayeux messages, performing the given callback in the given scope
* when a message for the given channel arrives.
* @param channel the channel the listener is interested to
* @param scope the scope of the callback
* @param callback the callback to call when a message is delivered to the channel
* @returns the subscription handle to be passed to {@link #removeListener(object)}
* @see #removeListener(object)
*/
this.addListener = function(channel, scope, callback)
{
// The data structure is a map<channel, subscription[]>, where each subscription
// holds the callback to be called and its scope.
// Normalize arguments
if (!callback)
{
callback = scope;
scope = undefined;
}
var subscription = {
scope: scope,
callback: callback
};
var subscriptions = _listeners[channel];
if (!subscriptions)
{
subscriptions = [];
_listeners[channel] = subscriptions;
}
// Pushing onto an array appends at the end and returns the id associated with the element increased by 1.
// Note that if:
// a.push('a'); var hb=a.push('b'); delete a[hb-1]; var hc=a.push('c');
// then:
// hc==3, a.join()=='a',,'c', a.length==3
var subscriptionIndex = subscriptions.push(subscription) - 1;
_debug('Added listener: channel \'{}\', callback \'{}\', index {}', channel, callback.name, subscriptionIndex);
// The subscription to allow removal of the listener is made of the channel and the index
return [channel, subscriptionIndex];
};
/**
* Removes the subscription obtained with a call to {@link #addListener(string, object, function)}.
* @param subscription the subscription to unsubscribe.
*/
this.removeListener = function(subscription)
{
var subscriptions = _listeners[subscription[0]];
if (subscriptions)
{
delete subscriptions[subscription[1]];
_debug('Removed listener: channel \'{}\', index {}', subscription[0], subscription[1]);
}
};
/**
* Removes all listeners registered with {@link #addListener(channel, scope, callback)} or
* {@link #subscribe(channel, scope, callback)}.
*/
this.clearListeners = function()
{
_listeners = {};
};
/**
* Returns a string representing the status of the bayeux communication with the comet server.
*/
this.getStatus = function()
{
return _status;
};
/**
* Sets the backoff period used to increase the backoff time when retrying an unsuccessful or failed message.
* Default value is 1 second, which means if there is a persistent failure the retries will happen
* after 1 second, then after 2 seconds, then after 3 seconds, etc. So for example with 15 seconds of
* elapsed time, there will be 5 retries (at 1, 3, 6, 10 and 15 seconds elapsed).
* @param period the backoff period to set
* @see #getBackoffIncrement()
*/
this.setBackoffIncrement = function(period)
{
_backoffIncrement = period;
};
/**
* Returns the backoff period used to increase the backoff time when retrying an unsuccessful or failed message.
* @see #setBackoffIncrement(period)
*/
this.getBackoffIncrement = function()
{
return _backoffIncrement;
};
/**
* Returns the backoff period to wait before retrying an unsuccessful or failed message.
*/
this.getBackoffPeriod = function()
{
return _backoff;
};
/**
* Sets the log level for console logging.
* Valid values are the strings 'error', 'warn', 'info' and 'debug', from
* less verbose to more verbose.
* @param level the log level string
*/
this.setLogLevel = function(level)
{
_logLevel = level;
};
/**
* Registers an extension whose callbacks are called for every incoming message
* (that comes from the server to this client implementation) and for every
* outgoing message (that originates from this client implementation for the
* server).
* The format of the extension object is the following:
* <pre>
* {
* incoming: function(message) { ... },
* outgoing: function(message) { ... }
* }
* Both properties are optional, but if they are present they will be called
* respectively for each incoming message and for each outgoing message.
* </pre>
* @param name the name of the extension
* @param extension the extension to register
* @return true if the extension was registered, false otherwise
* @see #unregisterExtension(name)
*/
this.registerExtension = function(name, extension)
{
var existing = false;
for (var i = 0; i < _extensions.length; ++i)
{
var existingExtension = _extensions[i];
if (existingExtension.name == name)
{
existing = true;
return false;
}
}
if (!existing)
{
_extensions.push({
name: name,
extension: extension
});
_debug('Registered extension \'{}\'', name);
return true;
}
else
{
_info('Could not register extension with name \'{}\': another extension with the same name already exists');
return false;
}
};
/**
* Unregister an extension previously registered with
* {@link #registerExtension(name, extension)}.
* @param name the name of the extension to unregister.
* @return true if the extension was unregistered, false otherwise
*/
this.unregisterExtension = function(name)
{
var unregistered = false;
$.each(_extensions, function(index, extension)
{
if (extension.name == name)
{
_extensions.splice(index, 1);
unregistered = true;
_debug('Unregistered extension \'{}\'', name);
return false;
}
});
return unregistered;
};
/**
* Starts a the batch of messages to be sent in a single request.
* @see _endBatch(deliverMessages)
*/
function _startBatch()
{
++_batch;
};
/**
* Ends the batch of messages to be sent in a single request,
* optionally delivering messages present in the message queue depending
* on the given argument.
* @param deliverMessages whether to deliver the messages in the queue or not
* @see _startBatch()
*/
function _endBatch(deliverMessages)
{
--_batch;
if (_batch < 0) _batch = 0;
if (deliverMessages && _batch == 0 && !_isDisconnected())
{
var messages = _messageQueue;
_messageQueue = [];
if (messages.length > 0) _deliver(messages, false);
}
};
function _nextMessageId()
{
return ++_messageId;
};
/**
* Converts the given response into an array of bayeux messages
* @param response the response to convert
* @return an array of bayeux messages obtained by converting the response
*/
function _convertToMessages(response)
{
if (response === undefined) return [];
if (response instanceof Array) return response;
if (response instanceof String || typeof response == 'string') return eval('(' + response + ')');
if (response instanceof Object) return [response];
throw 'Conversion Error ' + response + ', typeof ' + (typeof response);
};
function _setStatus(newStatus)
{
_debug('{} -> {}', _status, newStatus);
_status = newStatus;
};
function _isDisconnected()
{
return _status == 'disconnecting' || _status == 'disconnected';
};
/**
* Sends the initial handshake message
*/
function _handshake(handshakeProps)
{
_debug('Starting handshake');
_clientId = null;
// Start a batch.
// This is needed because handshake and connect are async.
// It may happen that the application calls init() then subscribe()
// and the subscribe message is sent before the connect message, if
// the subscribe message is not held until the connect message is sent.
// So here we start a batch to hold temporarly any message until
// the connection is fully established.
_batch = 0;
_startBatch();
// Save the original properties provided by the user
// Deep copy to avoid the user to be able to change them later
_handshakeProps = $.extend(true, {}, handshakeProps);
var bayeuxMessage = {
version: '1.0',
minimumVersion: '0.9',
channel: '/meta/handshake',
supportedConnectionTypes: _xd ? ['callback-polling'] : ['long-polling', 'callback-polling']
};
// Do not allow the user to mess with the required properties,
// so merge first the user properties and *then* the bayeux message
var message = $.extend({}, handshakeProps, bayeuxMessage);
// We started a batch to hold the application messages,
// so here we must bypass it and deliver immediately.
_setStatus('handshaking');
_deliver([message], false);
};
function _findTransport(handshakeResponse)
{
var transportTypes = handshakeResponse.supportedConnectionTypes;
if (_xd)
{
// If we are cross domain, check if the server supports it, that's the only option
if ($.inArray('callback-polling', transportTypes) >= 0) return _transport;
}
else
{
// Check if we can keep long-polling
if ($.inArray('long-polling', transportTypes) >= 0) return _transport;
// The server does not support long-polling
if ($.inArray('callback-polling', transportTypes) >= 0) return newCallbackPollingTransport();
}
return null;
};
function _delayedHandshake()
{
_setStatus('handshaking');
_delayedSend(function()
{
_handshake(_handshakeProps);
});
};
function _delayedConnect()
{
_setStatus('connecting');
_delayedSend(function()
{
_connect();
});
};
function _delayedSend(operation)
{
_cancelDelayedSend();
var delay = _backoff;
_debug("Delayed send: backoff {}, interval {}", _backoff, _advice.interval);
if (_advice.interval && _advice.interval > 0)
delay += _advice.interval;
_scheduledSend = _setTimeout(operation, delay);
};
function _cancelDelayedSend()
{
if (_scheduledSend !== null) clearTimeout(_scheduledSend);
_scheduledSend = null;
};
function _setTimeout(funktion, delay)
{
return setTimeout(function()
{
try
{
funktion();
}
catch (x)
{
_debug('Exception during scheduled execution of function \'{}\': {}', funktion.name, x);
}
}, delay);
};
/**
* Sends the connect message
*/
function _connect()
{
_debug('Starting connect');
var message = {
channel: '/meta/connect',
connectionType: _transport.getType()
};
_setStatus('connecting');
_deliver([message], true);
_setStatus('connected');
};
function _send(message)
{
if (_batch > 0)
_messageQueue.push(message);
else
_deliver([message], false);
};
/**
* Delivers the messages to the comet server
* @param messages the array of messages to send
*/
function _deliver(messages, comet)
{
// We must be sure that the messages have a clientId.
// This is not guaranteed since the handshake may take time to return
// (and hence the clientId is not known yet) and the application
// may create other messages.
$.each(messages, function(index, message)
{
message['id'] = _nextMessageId();
if (_clientId) message['clientId'] = _clientId;
messages[index] = _applyOutgoingExtensions(message);
});
var self = this;
var envelope = {
url: _url,
messages: messages,
onSuccess: function(request, response)
{
try
{
_handleSuccess.call(self, request, response, comet);
}
catch (x)
{
_debug('Exception during execution of success callback: {}', x);
}
},
onFailure: function(request, reason, exception)
{
try
{
_handleFailure.call(self, request, messages, reason, exception, comet);
}
catch (x)
{
_debug('Exception during execution of failure callback: {}', x);
}
}
};
_debug('Sending request to {}, message(s): {}', envelope.url, JSON.stringify(envelope.messages));
_transport.send(envelope, comet);
};
function _applyIncomingExtensions(message)
{
for (var i = 0; i < _extensions.length; ++i)
{
var extension = _extensions[i];
var callback = extension.extension.incoming;
if (callback && typeof callback === 'function')
{
_debug('Calling incoming extension \'{}\', callback \'{}\'', extension.name, callback.name);
message = _applyExtension(extension.name, callback, message) || message;
}
}
return message;
};
function _applyOutgoingExtensions(message)
{
for (var i = 0; i < _extensions.length; ++i)
{
var extension = _extensions[i];
var callback = extension.extension.outgoing;
if (callback && typeof callback === 'function')
{
_debug('Calling outgoing extension \'{}\', callback \'{}\'', extension.name, callback.name);
message = _applyExtension(extension.name, callback, message) || message;
}
}
return message;
};
function _applyExtension(name, callback, message)
{
try
{
return callback(message);
}
catch (x)
{
_debug('Exception during execution of extension \'{}\': {}', name, x);
return message;
}
};
function _handleSuccess(request, response, comet)
{
var messages = _convertToMessages(response);
_debug('Received response {}', JSON.stringify(messages));
// Signal the transport it can deliver other queued requests
_transport.complete(request, true, comet);
for (var i = 0; i < messages.length; ++i)
{
var message = messages[i];
message = _applyIncomingExtensions(message);
if (message.advice) _advice = message.advice;
var channel = message.channel;
switch (channel)
{
case '/meta/handshake':
_handshakeSuccess(message);
break;
case '/meta/connect':
_connectSuccess(message);
break;
case '/meta/disconnect':
_disconnectSuccess(message);
break;
case '/meta/subscribe':
_subscribeSuccess(message);
break;
case '/meta/unsubscribe':
_unsubscribeSuccess(message);
break;
default:
_messageSuccess(message);
break;
}
}
};
function _handleFailure(request, messages, reason, exception, comet)
{
var xhr = request.xhr;
_debug('Request failed, status: {}, reason: {}, exception: {}', xhr && xhr.status, reason, exception);
// Signal the transport it can deliver other queued requests
_transport.complete(request, false, comet);
for (var i = 0; i < messages.length; ++i)
{
var message = messages[i];
var channel = message.channel;
switch (channel)
{
case '/meta/handshake':
_handshakeFailure(xhr, message);
break;
case '/meta/connect':
_connectFailure(xhr, message);
break;
case '/meta/disconnect':
_disconnectFailure(xhr, message);
break;
case '/meta/subscribe':
_subscribeFailure(xhr, message);
break;
case '/meta/unsubscribe':
_unsubscribeFailure(xhr, message);
break;
default:
_messageFailure(xhr, message);
break;
}
}
};
function _handshakeSuccess(message)
{
if (message.successful)
{
_debug('Handshake successful');
// Save clientId, figure out transport, then follow the advice to connect
_clientId = message.clientId;
var newTransport = _findTransport(message);
if (newTransport === null)
{
throw 'Could not agree on transport with server';
}
else
{
if (_transport.getType() != newTransport.getType())
{
_debug('Changing transport from {} to {}', _transport.getType(), newTransport.getType());
_transport = newTransport;
}
}
// Notify the listeners
// Here the new transport is in place, as well as the clientId, so
// the listener can perform a publish() if it wants, and the listeners
// are notified before the connect below.
_notifyListeners('/meta/handshake', message);
var action = _advice.reconnect ? _advice.reconnect : 'retry';
switch (action)
{
case 'retry':
_delayedConnect();
break;
default:
break;
}
}
else
{
_debug('Handshake unsuccessful');
var retry = !_isDisconnected() && _advice.reconnect != 'none';
if (!retry) _setStatus('disconnected');
_notifyListeners('/meta/handshake', message);
_notifyListeners('/meta/unsuccessful', message);
// Only try again if we haven't been disconnected and
// the advice permits us to retry the handshake
if (retry)
{
_increaseBackoff();
_debug('Handshake failure, backing off and retrying in {} ms', _backoff);
_delayedHandshake();
}
}
};
function _handshakeFailure(xhr, message)
{
_debug('Handshake failure');
// Notify listeners
var failureMessage = {
successful: false,
failure: true,
channel: '/meta/handshake',
request: message,
xhr: xhr,
advice: {
action: 'retry',
interval: _backoff
}
};
var retry = !_isDisconnected() && _advice.reconnect != 'none';
if (!retry) _setStatus('disconnected');
_notifyListeners('/meta/handshake', failureMessage);
_notifyListeners('/meta/unsuccessful', failureMessage);
// Only try again if we haven't been disconnected and the
// advice permits us to try again
if (retry)
{
_increaseBackoff();
_debug('Handshake failure, backing off and retrying in {} ms', _backoff);
_delayedHandshake();
}
};
function _connectSuccess(message)
{
var action = _isDisconnected() ? 'none' : (_advice.reconnect ? _advice.reconnect : 'retry');
if (!_isDisconnected()) _setStatus(action == 'retry' ? 'connecting' : 'disconnecting');
if (message.successful)
{
_debug('Connect successful');
// End the batch and allow held messages from the application
// to go to the server (see _handshake() where we start the batch).
// The batch is ended before notifying the listeners, so that
// listeners can batch other cometd operations
_endBatch(true);
// Notify the listeners after the status change but before the next connect
_notifyListeners('/meta/connect', message);
// Connect was successful.
// Normally, the advice will say "reconnect: 'retry', interval: 0"
// and the server will hold the request, so when a response returns
// we immediately call the server again (long polling)
switch (action)
{
case 'retry':
_resetBackoff();
_delayedConnect();
break;
default:
_resetBackoff();
_setStatus('disconnected');
break;
}
}
else
{
_debug('Connect unsuccessful');
// Notify the listeners after the status change but before the next action
_notifyListeners('/meta/connect', message);
_notifyListeners('/meta/unsuccessful', message);
// Connect was not successful.
// This may happen when the server crashed, the current clientId
// will be invalid, and the server will ask to handshake again
switch (action)
{
case 'retry':
_increaseBackoff();
_delayedConnect();
break;
case 'handshake':
// End the batch but do not deliver the messages until we connect successfully
_endBatch(false);
_resetBackoff();
_delayedHandshake();
break;
case 'none':
_resetBackoff();
_setStatus('disconnected');
break;
}
}
};
function _connectFailure(xhr, message)
{
_debug('Connect failure');
// Notify listeners
var failureMessage = {
successful: false,
failure: true,
channel: '/meta/connect',
request: message,
xhr: xhr,
advice: {
action: 'retry',
interval: _backoff
}
};
_notifyListeners('/meta/connect', failureMessage);
_notifyListeners('/meta/unsuccessful', failureMessage);
if (!_isDisconnected())
{
var action = _advice.reconnect ? _advice.reconnect : 'retry';
switch (action)
{
case 'retry':
_increaseBackoff();
_debug('Connect failure, backing off and retrying in {} ms', _backoff);
_delayedConnect();
break;
case 'handshake':
_resetBackoff();
_delayedHandshake();
break;
case 'none':
_resetBackoff();
break;
default:
_debug('Unrecognized reconnect value: {}', action);
break;
}
}
};
function _disconnectSuccess(message)
{
if (message.successful)
{
_debug('Disconnect successful');
_disconnect(false);
_notifyListeners('/meta/disconnect', message);
}
else
{
_debug('Disconnect unsuccessful');
_disconnect(true);
_notifyListeners('/meta/disconnect', message);
_notifyListeners('/meta/usuccessful', message);
}
};
function _disconnect(abort)
{
_cancelDelayedSend();
if (abort) _transport.abort();
_clientId = null;
_setStatus('disconnected');
_batch = 0;
_messageQueue = [];
_resetBackoff();
};
function _disconnectFailure(xhr, message)
{
_debug('Disconnect failure');
_disconnect(true);
var failureMessage = {
successful: false,
failure: true,
channel: '/meta/disconnect',
request: message,
xhr: xhr,
advice: {
action: 'none',
interval: 0
}
};
_notifyListeners('/meta/disconnect', failureMessage);
_notifyListeners('/meta/unsuccessful', failureMessage);
};
function _subscribeSuccess(message)
{
if (message.successful)
{
_debug('Subscribe successful');
_notifyListeners('/meta/subscribe', message);
}
else
{
_debug('Subscribe unsuccessful');
_notifyListeners('/meta/subscribe', message);
_notifyListeners('/meta/unsuccessful', message);
}
};
function _subscribeFailure(xhr, message)
{
_debug('Subscribe failure');
var failureMessage = {
successful: false,
failure: true,
channel: '/meta/subscribe',
request: message,
xhr: xhr,
advice: {
action: 'none',
interval: 0
}
};
_notifyListeners('/meta/subscribe', failureMessage);
_notifyListeners('/meta/unsuccessful', failureMessage);
};
function _unsubscribeSuccess(message)
{
if (message.successful)
{
_debug('Unsubscribe successful');
_notifyListeners('/meta/unsubscribe', message);
}
else
{
_debug('Unsubscribe unsuccessful');
_notifyListeners('/meta/unsubscribe', message);
_notifyListeners('/meta/unsuccessful', message);
}
};
function _unsubscribeFailure(xhr, message)
{
_debug('Unsubscribe failure');
var failureMessage = {
successful: false,
failure: true,
channel: '/meta/unsubscribe',
request: message,
xhr: xhr,
advice: {
action: 'none',
interval: 0
}
};
_notifyListeners('/meta/unsubscribe', failureMessage);
_notifyListeners('/meta/unsuccessful', failureMessage);
};
function _messageSuccess(message)
{
if (message.successful === undefined)
{
if (message.data)
{
// It is a plain message, and not a bayeux meta message
_notifyListeners(message.channel, message);
}
else
{
_debug('Unknown message {}', JSON.stringify(message));
}
}
else
{
if (message.successful)
{
_debug('Publish successful');
_notifyListeners('/meta/publish', message);
}
else
{
_debug('Publish unsuccessful');
_notifyListeners('/meta/publish', message);
_notifyListeners('/meta/unsuccessful', message);
}
}
};
function _messageFailure(xhr, message)
{
_debug('Publish failure');
var failureMessage = {
successful: false,
failure: true,
channel: message.channel,
request: message,
xhr: xhr,
advice: {
action: 'none',
interval: 0
}
};
_notifyListeners('/meta/publish', failureMessage);
_notifyListeners('/meta/unsuccessful', failureMessage);
};
function _notifyListeners(channel, message)
{
// Notify direct listeners
_notify(channel, message);
// Notify the globbing listeners
var channelParts = channel.split("/");
var last = channelParts.length - 1;
for (var i = last; i > 0; --i)
{
var channelPart = channelParts.slice(0, i).join('/') + '/*';
// We don't want to notify /foo/* if the channel is /foo/bar/baz,
// so we stop at the first non recursive globbing
if (i == last) _notify(channelPart, message);
// Add the recursive globber and notify
channelPart += '*';
_notify(channelPart, message);
}
};
function _notify(channel, message)
{
var subscriptions = _listeners[channel];
if (subscriptions && subscriptions.length > 0)
{
for (var i = 0; i < subscriptions.length; ++i)
{
var subscription = subscriptions[i];
// Subscriptions may come and go, so the array may have 'holes'
if (subscription)
{
try
{
_debug('Notifying subscription: channel \'{}\', callback \'{}\'', channel, subscription.callback.name);
subscription.callback.call(subscription.scope, message);
}
catch (x)
{
// Ignore exceptions from callbacks
_warn('Exception during execution of callback \'{}\' on channel \'{}\' for message {}, exception: {}', subscription.callback.name, channel, JSON.stringify(message), x);
}
}
}
}
};
function _resetBackoff()
{
_backoff = 0;
};
function _increaseBackoff()
{
if (_backoff < _maxBackoff) _backoff += _backoffIncrement;
};
var _error = this._error = function(text, args)
{
_log('error', _format.apply(this, arguments));
};
var _warn = this._warn = function(text, args)
{
_log('warn', _format.apply(this, arguments));
};
var _info = this._info = function(text, args)
{
_log('info', _format.apply(this, arguments));
};
var _debug = this._debug = function(text, args)
{
_log('debug', _format.apply(this, arguments));
};
function _log(level, text)
{
var priority = _logPriorities[level];
var configPriority = _logPriorities[_logLevel];
if (!configPriority) configPriority = _logPriorities['info'];
if (priority >= configPriority)
{
if (window.console) window.console.log(text);
}
};
function _format(text)
{
var braces = /\{\}/g;
var result = '';
var start = 0;
var count = 0;
while (braces.test(text))
{
result += text.substr(start, braces.lastIndex - start - 2);
var arg = arguments[++count];
result += arg !== undefined ? arg : '{}';
start = braces.lastIndex;
}
result += text.substr(start, text.length - start);
return result;
};
function newLongPollingTransport()
{
return $.extend({}, new Transport('long-polling'), new LongPollingTransport());
};
function newCallbackPollingTransport()
{
return $.extend({}, new Transport('callback-polling'), new CallbackPollingTransport());
};
/**
* Base object with the common functionality for transports.
* The key responsibility is to allow at most 2 outstanding requests to the server,
* to avoid that requests are sent behind a long poll.
* To achieve this, we have one reserved request for the long poll, and all other
* requests are serialized one after the other.
*/
var Transport = function(type)
{
var _maxRequests = 2;
var _requestIds = 0;
var _cometRequest = null;
var _requests = [];
var _packets = [];
this.getType = function()
{
return type;
};
this.send = function(packet, comet)
{
if (comet)
_cometSend(this, packet);
else
_send(this, packet);
};
function _cometSend(self, packet)
{
if (_cometRequest !== null) throw 'Concurrent comet requests not allowed, request ' + _cometRequest.id + ' not yet completed';
var requestId = ++_requestIds;
_debug('Beginning comet request {}', requestId);
var request = {id: requestId};
_debug('Delivering comet request {}', requestId);
self.deliver(packet, request);
_cometRequest = request;
};
function _send(self, packet)
{
var requestId = ++_requestIds;
_debug('Beginning request {}, {} other requests, {} queued requests', requestId, _requests.length, _packets.length);
var request = {id: requestId};
// Consider the comet request which should always be present
if (_requests.length < _maxRequests - 1)
{
_debug('Delivering request {}', requestId);
self.deliver(packet, request);
_requests.push(request);
}
else
{
_packets.push([packet, request]);
_debug('Queued request {}, {} queued requests', requestId, _packets.length);
}
};
this.complete = function(request, success, comet)
{
if (comet)
_cometComplete(request);
else
_complete(this, request, success);
};
function _cometComplete(request)
{
var requestId = request.id;
if (_cometRequest !== request) throw 'Comet request mismatch, completing request ' + requestId;
// Reset comet request
_cometRequest = null;
_debug('Ended comet request {}', requestId);
};
function _complete(self, request, success)
{
var requestId = request.id;
var index = $.inArray(request, _requests);
// The index can be negative the request has been aborted
if (index >= 0) _requests.splice(index, 1);
_debug('Ended request {}, {} other requests, {} queued requests', requestId, _requests.length, _packets.length);
if (_packets.length > 0)
{
var packet = _packets.shift();
if (success)
{
_debug('Dequeueing and sending request {}, {} queued requests', packet[1].id, _packets.length);
_send(self, packet[0]);
}
else
{
_debug('Dequeueing and failing request {}, {} queued requests', packet[1].id, _packets.length);
// Keep the semantic of calling response callbacks asynchronously after the request
setTimeout(function() { packet[0].onFailure(packet[1], 'error'); }, 0);
}
}
};
this.abort = function()
{
for (var i = 0; i < _requests.length; ++i)
{
var request = _requests[i];
_debug('Aborting request {}', request.id);
if (request.xhr) request.xhr.abort();
}
if (_cometRequest)
{
_debug('Aborting comet request {}', _cometRequest.id);
if (_cometRequest.xhr) _cometRequest.xhr.abort();
}
_cometRequest = null;
_requests = [];
_packets = [];
};
};
var LongPollingTransport = function()
{
this.deliver = function(packet, request)
{
request.xhr = $.ajax({
url: packet.url,
type: 'POST',
contentType: 'text/json;charset=UTF-8',
beforeSend: function(xhr)
{
xhr.setRequestHeader('Connection', 'Keep-Alive');
return true;
},
data: JSON.stringify(packet.messages),
success: function(response) { packet.onSuccess(request, response); },
error: function(xhr, reason, exception) { packet.onFailure(request, reason, exception); }
});
};
};
var CallbackPollingTransport = function()
{
var _maxLength = 2000;
this.deliver = function(packet, request)
{
// Microsoft Internet Explorer has a 2083 URL max length
// We must ensure that we stay within that length
var messages = JSON.stringify(packet.messages);
// Encode the messages because all brackets, quotes, commas, colons, etc
// present in the JSON will be URL encoded, taking many more characters
var urlLength = packet.url.length + encodeURI(messages).length;
_debug('URL length: {}', urlLength);
// Let's stay on the safe side and use 2000 instead of 2083
// also because we did not count few characters among which
// the parameter name 'message' and the parameter 'jsonp',
// which sum up to about 50 chars
if (urlLength > _maxLength)
{
var x = packet.messages.length > 1 ?
'Too many bayeux messages in the same batch resulting in message too big ' +
'(' + urlLength + ' bytes, max is ' + _maxLength + ') for transport ' + this.getType() :
'Bayeux message too big (' + urlLength + ' bytes, max is ' + _maxLength + ') ' +
'for transport ' + this.getType();
// Keep the semantic of calling response callbacks asynchronously after the request
_setTimeout(function() { packet.onFailure(request, 'error', x); }, 0);
}
else
{
$.ajax({
url: packet.url,
type: 'GET',
dataType: 'jsonp',
jsonp: 'jsonp',
beforeSend: function(xhr)
{
xhr.setRequestHeader('Connection', 'Keep-Alive');
return true;
},
data:
{
// In callback-polling, the content must be sent via the 'message' parameter
message: messages
},
success: function(response) { packet.onSuccess(request, response); },
error: function(xhr, reason, exception) { packet.onFailure(request, reason, exception); }
});
}
};
};
};
/**
* The JS object that exposes the comet API to applications
*/
$.cometd = new $.Cometd(); // The default instance
})(jQuery);
|