lib/dojo/OpenAjax.js

   1 /*******************************************************************************
   2  * OpenAjax.js
   3  *
   4  * Reference implementation of the OpenAjax Hub, as specified by OpenAjax Alliance.
   5  * Specification is under development at:
   6  *
   7  *   http://www.openajax.org/member/wiki/OpenAjax_Hub_Specification
   8  *
   9  * Copyright 2006-2007 OpenAjax Alliance
  10  *
  11  * Licensed under the Apache License, Version 2.0 (the "License"); you may not
  12  * use this file except in compliance with the License. You may obtain a copy
  13  * of the License at http://www.apache.org/licenses/LICENSE-2.0 . Unless
  14  * required by applicable law or agreed to in writing, software distributed
  15  * under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
  16  * CONDITIONS OF ANY KIND, either express or implied. See the License for the
  17  * specific language governing permissions and limitations under the License.
  18  *
  19  ******************************************************************************/
  20
  21 // prevent re-definition of the OpenAjax object
  22 if(!window["OpenAjax"]){
  23         OpenAjax = new function(){
  24                 // summary:
  25                 //              the OpenAjax hub
  26                 // description:
  27                 //              see http://www.openajax.org/member/wiki/OpenAjax_Hub_Specification
  28
  29                 var libs = {};
  30                 var ooh = "org.openajax.hub.";
  31
  32                 var h = {};
  33                 this.hub = h;
  34                 h.implementer = "http://openajax.org";
  35                 h.implVersion = "0.6";
  36                 h.specVersion = "0.6";
  37                 h.implExtraData = {};
  38                 h.libraries = libs;
  39
  40                 h.registerLibrary = function(prefix, nsURL, version, extra){
  41                         libs[prefix] = {
  42                                 prefix: prefix,
  43                                 namespaceURI: nsURL,
  44                                 version: version,
  45                                 extraData: extra
  46                         };
  47                         this.publish(ooh+"registerLibrary", libs[prefix]);
  48                 };
  49                 h.unregisterLibrary = function(prefix){
  50                         this.publish(ooh+"unregisterLibrary", libs[prefix]);
  51                         delete libs[prefix];
  52                 };
  53
  54                 h._subscriptions = { c:{}, s:[] };
  55                 h._cleanup = [];
  56                 h._subIndex = 0;
  57                 h._pubDepth = 0;
  58
  59                 h.subscribe = function(name, callback, scope, subscriberData, filter){
  60                         if(!scope){
  61                                 scope = window;
  62                         }
  63                         var handle = name + "." + this._subIndex;
  64                         var sub = { scope: scope, cb: callback, fcb: filter, data: subscriberData, sid: this._subIndex++, hdl: handle };
  65                         var path = name.split(".");
  66                         this._subscribe(this._subscriptions, path, 0, sub);
  67                         return handle;
  68                 };
  69
  70                 h.publish = function(name, message){
  71                         var path = name.split(".");
  72                         this._pubDepth++;
  73                         this._publish(this._subscriptions, path, 0, name, message);
  74                         this._pubDepth--;
  75                         if((this._cleanup.length > 0) && (this._pubDepth == 0)){
  76                                 for(var i = 0; i < this._cleanup.length; i++){
  77                                         this.unsubscribe(this._cleanup[i].hdl);
  78                                 }
  79                                 delete(this._cleanup);
  80                                 this._cleanup = [];
  81                         }
  82                 };
  83
  84                 h.unsubscribe = function(sub){
  85                         var path = sub.split(".");
  86                         var sid = path.pop();
  87                         this._unsubscribe(this._subscriptions, path, 0, sid);
  88                 };
  89
  90                 h._subscribe = function(tree, path, index, sub){
  91                         var token = path[index];
  92                         if(index == path.length){
  93                                 tree.s.push(sub);
  94                         }else{
  95                                 if(typeof tree.c == "undefined"){
  96                                         tree.c = {};
  97                                 }
  98                                 if(typeof tree.c[token] == "undefined"){
  99                                         tree.c[token] = { c: {}, s: [] };
 100                                 }
 101                                 this._subscribe(tree.c[token], path, index + 1, sub);
 102                         }
 103                 };
 104
 105                 h._publish = function(tree, path, index, name, msg){
 106                         if(typeof tree != "undefined"){
 107                                 var node;
 108                                 if(index == path.length){
 109                                         node = tree;
 110                                 }else{
 111                                         this._publish(tree.c[path[index]], path, index + 1, name, msg);
 112                                         this._publish(tree.c["*"], path, index + 1, name, msg);
 113                                         node = tree.c["**"];
 114                                 }
 115                                 if(typeof node != "undefined"){
 116                                         var callbacks = node.s;
 117                                         var max = callbacks.length;
 118                                         for(var i = 0; i < max; i++){
 119                                                 if(callbacks[i].cb){
 120                                                         var sc = callbacks[i].scope;
 121                                                         var cb = callbacks[i].cb;
 122                                                         var fcb = callbacks[i].fcb;
 123                                                         var d = callbacks[i].data;
 124                                                         if(typeof cb == "string"){
 125                                                                 // get a function object
 126                                                                 cb = sc[cb];
 127                                                         }
 128                                                         if(typeof fcb == "string"){
 129                                                                 // get a function object
 130                                                                 fcb = sc[fcb];
 131                                                         }
 132                                                         if((!fcb) ||
 133                                                                 (fcb.call(sc, name, msg, d))){
 134                                                                 cb.call(sc, name, msg, d);
 135                                                         }
 136                                                 }
 137                                         }
 138                                 }
 139                         }
 140                 };
 141
 142                 h._unsubscribe = function(tree, path, index, sid){
 143                         if(typeof tree != "undefined"){
 144                                 if(index < path.length){
 145                                         var childNode = tree.c[path[index]];
 146                                         this._unsubscribe(childNode, path, index + 1, sid);
 147                                         if(childNode.s.length == 0){
 148                                                 for(var x in childNode.c)
 149                                                         return;
 150                                                 delete tree.c[path[index]];
 151                                         }
 152                                         return;
 153                                 }
 154                                 else{
 155                                         var callbacks = tree.s;
 156                                         var max = callbacks.length;
 157                                         for(var i = 0; i < max; i++){
 158                                                 if(sid == callbacks[i].sid){
 159                                                         if(this._pubDepth > 0){
 160                                                                 callbacks[i].cb = null;
 161                                                                 this._cleanup.push(callbacks[i]);
 162                                                         }
 163                                                         else
 164                                                                 callbacks.splice(i, 1);
 165                                                         return;
 166                                                 }
 167                                         }
 168                                 }
 169                         }
 170                 };
 171
 172                 // The following function is provided for automatic testing purposes.
 173                 // It is not expected to be deployed in run-time OpenAjax Hub implementations.
 174                 h.reinit = function(){
 175                         for (var lib in OpenAjax.hub.libraries){
 176                                 delete OpenAjax.hub.libraries[lib];
 177                         }
 178                         OpenAjax.hub.registerLibrary("OpenAjax", "http://openajax.org/hub", "0.6", {});
 179
 180                         delete OpenAjax._subscriptions;
 181                         OpenAjax._subscriptions = {c:{},s:[]};
 182                         delete OpenAjax._cleanup;
 183                         OpenAjax._cleanup = [];
 184                         OpenAjax._subIndex = 0;
 185                         OpenAjax._pubDepth = 0;
 186                 };
 187         };
 188
 189         // Register the OpenAjax Hub itself as a library.
 190         OpenAjax.hub.registerLibrary("OpenAjax", "http://openajax.org/hub", "0.6", {});
 191
 192 }