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
|
if(!dojo._hasResource["dojo._base.connect"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
dojo._hasResource["dojo._base.connect"] = true;
dojo.provide("dojo._base.connect");
dojo.require("dojo._base.lang");
// this file courtesy of the TurboAjax Group, licensed under a Dojo CLA
// low-level delegation machinery
dojo._listener = {
// create a dispatcher function
getDispatcher: function(){
// following comments pulled out-of-line to prevent cloning them
// in the returned function.
// - indices (i) that are really in the array of listeners (ls) will
// not be in Array.prototype. This is the 'sparse array' trick
// that keeps us safe from libs that take liberties with built-in
// objects
// - listener is invoked with current scope (this)
return function(){
var ap=Array.prototype, c=arguments.callee, ls=c._listeners, t=c.target;
// return value comes from original target function
var r=t && t.apply(this, arguments);
// invoke listeners after target function
for(var i in ls){
if(!(i in ap)){
ls[i].apply(this, arguments);
}
}
// return value comes from original target function
return r;
}
},
// add a listener to an object
add: function(/*Object*/ source, /*String*/ method, /*Function*/ listener){
// Whenever 'method' is invoked, 'listener' will have the same scope.
// Trying to supporting a context object for the listener led to
// complexity.
// Non trivial to provide 'once' functionality here
// because listener could be the result of a dojo.hitch call,
// in which case two references to the same hitch target would not
// be equivalent.
source = source || dojo.global;
// The source method is either null, a dispatcher, or some other function
var f = source[method];
// Ensure a dispatcher
if(!f||!f._listeners){
var d = dojo._listener.getDispatcher();
// original target function is special
d.target = f;
// dispatcher holds a list of listeners
d._listeners = [];
// redirect source to dispatcher
f = source[method] = d;
}
// The contract is that a handle is returned that can
// identify this listener for disconnect.
//
// The type of the handle is private. Here is it implemented as Integer.
// DOM event code has this same contract but handle is Function
// in non-IE browsers.
//
// We could have separate lists of before and after listeners.
return f._listeners.push(listener) ; /*Handle*/
},
// remove a listener from an object
remove: function(/*Object*/ source, /*String*/ method, /*Handle*/ handle){
var f = (source||dojo.global)[method];
// remember that handle is the index+1 (0 is not a valid handle)
if(f && f._listeners && handle--){
delete f._listeners[handle];
}
}
};
// Multiple delegation for arbitrary methods.
// This unit knows nothing about DOM,
// but we include DOM aware
// documentation and dontFix
// argument here to help the autodocs.
// Actual DOM aware code is in event.js.
dojo.connect = function(/*Object|null*/ obj,
/*String*/ event,
/*Object|null*/ context,
/*String|Function*/ method,
/*Boolean*/ dontFix){
// summary:
// Create a link that calls one function when another executes.
//
// description:
// Connects method to event, so that after event fires, method
// does too. All connected functions are passed the same arguments as
// the event function was initially called with. You may connect as
// many methods to event as needed.
//
// event must be a string. If obj is null, dojo.global is used.
//
// null arguments may simply be omitted.
//
// obj[event] can resolve to a function or undefined (null).
// If obj[event] is null, it is assigned a function.
//
// The return value is a handle that is needed to
// remove this connection with dojo.disconnect.
//
// obj:
// The source object for the event function.
// Defaults to dojo.global if null.
// If obj is a DOM node, the connection is delegated
// to the DOM event manager (unless dontFix is true).
//
// event:
// String name of the event function in obj.
// I.e. identifies a property obj[event].
//
// context:
// The object that method will receive as "this".
//
// If context is null and method is a function, then method
// inherits the context of event.
//
// If method is a string then context must be the source
// object object for method (context[method]). If context is null,
// dojo.global is used.
//
// method:
// A function reference, or name of a function in context.
// The function identified by method fires after event does.
// method receives the same arguments as the event.
// See context argument comments for information on method's scope.
//
// dontFix:
// If obj is a DOM node, set dontFix to true to prevent delegation
// of this connection to the DOM event manager.
//
// example:
// When obj.onchange(), do ui.update():
// | dojo.connect(obj, "onchange", ui, "update");
// | dojo.connect(obj, "onchange", ui, ui.update); // same
//
// example:
// Using return value for disconnect:
// | var link = dojo.connect(obj, "onchange", ui, "update");
// | ...
// | dojo.disconnect(link);
//
// example:
// When onglobalevent executes, watcher.handler is invoked:
// | dojo.connect(null, "onglobalevent", watcher, "handler");
//
// example:
// When ob.onCustomEvent executes, customEventHandler is invoked:
// | dojo.connect(ob, "onCustomEvent", null, "customEventHandler");
// | dojo.connect(ob, "onCustomEvent", "customEventHandler"); // same
//
// example:
// When ob.onCustomEvent executes, customEventHandler is invoked
// with the same scope (this):
// | dojo.connect(ob, "onCustomEvent", null, customEventHandler);
// | dojo.connect(ob, "onCustomEvent", customEventHandler); // same
//
// example:
// When globalEvent executes, globalHandler is invoked
// with the same scope (this):
// | dojo.connect(null, "globalEvent", null, globalHandler);
// | dojo.connect("globalEvent", globalHandler); // same
// normalize arguments
var a=arguments, args=[], i=0;
// if a[0] is a String, obj was ommited
args.push(dojo.isString(a[0]) ? null : a[i++], a[i++]);
// if the arg-after-next is a String or Function, context was NOT omitted
var a1 = a[i+1];
args.push(dojo.isString(a1)||dojo.isFunction(a1) ? a[i++] : null, a[i++]);
// absorb any additional arguments
for(var l=a.length; i<l; i++){ args.push(a[i]); }
// do the actual work
return dojo._connect.apply(this, args); /*Handle*/
}
// used by non-browser hostenvs. always overriden by event.js
dojo._connect = function(obj, event, context, method){
var l=dojo._listener, h=l.add(obj, event, dojo.hitch(context, method));
return [obj, event, h, l]; // Handle
}
dojo.disconnect = function(/*Handle*/ handle){
// summary:
// Remove a link created by dojo.connect.
// description:
// Removes the connection between event and the method referenced by handle.
// handle:
// the return value of the dojo.connect call that created the connection.
if(handle && handle[0] !== undefined){
dojo._disconnect.apply(this, handle);
// let's not keep this reference
delete handle[0];
}
}
dojo._disconnect = function(obj, event, handle, listener){
listener.remove(obj, event, handle);
}
// topic publish/subscribe
dojo._topics = {};
dojo.subscribe = function(/*String*/ topic, /*Object|null*/ context, /*String|Function*/ method){
// summary:
// Attach a listener to a named topic. The listener function is invoked whenever the
// named topic is published (see: dojo.publish).
// Returns a handle which is needed to unsubscribe this listener.
// context:
// Scope in which method will be invoked, or null for default scope.
// method:
// The name of a function in context, or a function reference. This is the function that
// is invoked when topic is published.
// example:
// | dojo.subscribe("alerts", null, function(caption, message){ alert(caption + "\n" + message); };
// | dojo.publish("alerts", [ "read this", "hello world" ]);
// support for 2 argument invocation (omitting context) depends on hitch
return [topic, dojo._listener.add(dojo._topics, topic, dojo.hitch(context, method))]; /*Handle*/
}
dojo.unsubscribe = function(/*Handle*/ handle){
// summary:
// Remove a topic listener.
// handle:
// The handle returned from a call to subscribe.
// example:
// | var alerter = dojo.subscribe("alerts", null, function(caption, message){ alert(caption + "\n" + message); };
// | ...
// | dojo.unsubscribe(alerter);
if(handle){
dojo._listener.remove(dojo._topics, handle[0], handle[1]);
}
}
dojo.publish = function(/*String*/ topic, /*Array*/ args){
// summary:
// Invoke all listener method subscribed to topic.
// topic:
// The name of the topic to publish.
// args:
// An array of arguments. The arguments will be applied
// to each topic subscriber (as first class parameters, via apply).
// example:
// | dojo.subscribe("alerts", null, function(caption, message){ alert(caption + "\n" + message); };
// | dojo.publish("alerts", [ "read this", "hello world" ]);
// Note that args is an array, which is more efficient vs variable length
// argument list. Ideally, var args would be implemented via Array
// throughout the APIs.
var f = dojo._topics[topic];
if(f){
f.apply(this, args||[]);
}
}
dojo.connectPublisher = function( /*String*/ topic,
/*Object|null*/ obj,
/*String*/ event){
// summary:
// Ensure that everytime obj.event() is called, a message is published
// on the topic. Returns a handle which can be passed to
// dojo.disconnect() to disable subsequent automatic publication on
// the topic.
// topic:
// The name of the topic to publish.
// obj:
// The source object for the event function. Defaults to dojo.global
// if null.
// event:
// The name of the event function in obj.
// I.e. identifies a property obj[event].
// example:
// | dojo.connectPublisher("/ajax/start", dojo, "xhrGet"};
var pf = function(){ dojo.publish(topic, arguments); }
return (event) ? dojo.connect(obj, event, pf) : dojo.connect(obj, pf); //Handle
};
}
|