source: Dev/trunk/src/client/dojo/OpenAjax.js

/*******************************************************************************
 * OpenAjax.js
 *
 * Reference implementation of the OpenAjax Hub, as specified by OpenAjax Alliance.
 * Specification is under development at:
 *
 *   http://www.openajax.org/member/wiki/OpenAjax_Hub_Specification
 *
 * Copyright 2006-2007 OpenAjax Alliance
 *
 * 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.
 *
 ******************************************************************************/

// prevent re-definition of the OpenAjax object
if(!window["OpenAjax"]){
        OpenAjax = new function(){
                // summary:
                //              the OpenAjax hub
                // description:
                //              see http://www.openajax.org/member/wiki/OpenAjax_Hub_Specification

                var libs = {};
                var ooh = "org.openajax.hub.";

                var h = {};
                this.hub = h;
                h.implementer = "http://openajax.org";
                h.implVersion = "0.6";
                h.specVersion = "0.6";
                h.implExtraData = {};
                h.libraries = libs;

                h.registerLibrary = function(prefix, nsURL, version, extra){
                        libs[prefix] = {
                                prefix: prefix,
                                namespaceURI: nsURL,
                                version: version,
                                extraData: extra
                        };
                        this.publish(ooh+"registerLibrary", libs[prefix]);
                };
                h.unregisterLibrary = function(prefix){
                        this.publish(ooh+"unregisterLibrary", libs[prefix]);
                        delete libs[prefix];
                };

                h._subscriptions = { c:{}, s:[] };
                h._cleanup = [];
                h._subIndex = 0;
                h._pubDepth = 0;

                h.subscribe = function(name, callback, scope, subscriberData, filter){
                        if(!scope){
                                scope = window;
                        }
                        var handle = name + "." + this._subIndex;
                        var sub = { scope: scope, cb: callback, fcb: filter, data: subscriberData, sid: this._subIndex++, hdl: handle };
                        var path = name.split(".");
                        this._subscribe(this._subscriptions, path, 0, sub);
                        return handle;
                };

                h.publish = function(name, message){
                        var path = name.split(".");
                        this._pubDepth++;
                        this._publish(this._subscriptions, path, 0, name, message);
                        this._pubDepth--;
                        if((this._cleanup.length > 0) && (this._pubDepth == 0)){
                                for(var i = 0; i < this._cleanup.length; i++){
                                        this.unsubscribe(this._cleanup[i].hdl);
                                }
                                delete(this._cleanup);
                                this._cleanup = [];
                        }
                };

                h.unsubscribe = function(sub){
                        var path = sub.split(".");
                        var sid = path.pop();
                        this._unsubscribe(this._subscriptions, path, 0, sid);
                };
                
                h._subscribe = function(tree, path, index, sub){
                        var token = path[index];
                        if(index == path.length){
                                tree.s.push(sub);
                        }else{
                                if(typeof tree.c == "undefined"){
                                        tree.c = {};
                                }
                                if(typeof tree.c[token] == "undefined"){
                                        tree.c[token] = { c: {}, s: [] };
                                }
                                this._subscribe(tree.c[token], path, index + 1, sub);
                        }
                };

                h._publish = function(tree, path, index, name, msg){
                        if(typeof tree != "undefined"){
                                var node;
                                if(index == path.length){
                                        node = tree;
                                }else{
                                        this._publish(tree.c[path[index]], path, index + 1, name, msg);
                                        this._publish(tree.c["*"], path, index + 1, name, msg);
                                        node = tree.c["**"];
                                }
                                if(typeof node != "undefined"){
                                        var callbacks = node.s;
                                        var max = callbacks.length;
                                        for(var i = 0; i < max; i++){
                                                if(callbacks[i].cb){
                                                        var sc = callbacks[i].scope;
                                                        var cb = callbacks[i].cb;
                                                        var fcb = callbacks[i].fcb;
                                                        var d = callbacks[i].data;
                                                        if(typeof cb == "string"){
                                                                // get a function object
                                                                cb = sc[cb];
                                                        }
                                                        if(typeof fcb == "string"){
                                                                // get a function object
                                                                fcb = sc[fcb];
                                                        }
                                                        if((!fcb) ||
                                                                (fcb.call(sc, name, msg, d))){
                                                                cb.call(sc, name, msg, d);
                                                        }
                                                }
                                        }
                                }
                        }
                };
                        
                h._unsubscribe = function(tree, path, index, sid){
                        if(typeof tree != "undefined"){
                                if(index < path.length){
                                        var childNode = tree.c[path[index]];
                                        this._unsubscribe(childNode, path, index + 1, sid);
                                        if(childNode.s.length == 0){
                                                for(var x in childNode.c)
                                                        return;
                                                delete tree.c[path[index]];
                                        }
                                        return;
                                }
                                else{
                                        var callbacks = tree.s;
                                        var max = callbacks.length;
                                        for(var i = 0; i < max; i++){
                                                if(sid == callbacks[i].sid){
                                                        if(this._pubDepth > 0){
                                                                callbacks[i].cb = null;
                                                                this._cleanup.push(callbacks[i]);
                                                        }
                                                        else
                                                                callbacks.splice(i, 1);
                                                        return;
                                                }
                                        }
                                }
                        }
                };

                // The following function is provided for automatic testing purposes.
                // It is not expected to be deployed in run-time OpenAjax Hub implementations.
                h.reinit = function(){
                        for (var lib in OpenAjax.hub.libraries){
                                delete OpenAjax.hub.libraries[lib];
                        }
                        OpenAjax.hub.registerLibrary("OpenAjax", "http://openajax.org/hub", "0.6", {});

                        delete OpenAjax._subscriptions;
                        OpenAjax._subscriptions = {c:{},s:[]};
                        delete OpenAjax._cleanup;
                        OpenAjax._cleanup = [];
                        OpenAjax._subIndex = 0;
                        OpenAjax._pubDepth = 0;
                };
        };

        // Register the OpenAjax Hub itself as a library.
        OpenAjax.hub.registerLibrary("OpenAjax", "http://openajax.org/hub", "0.6", {});

}