dojo.require("dojo.event.common");
dojo.provide("dojo.event.topic");
dojo.event.topic = new function(){
this.topics = {};
this.getTopic = function(/*String*/topic){
// summary:
// returns a topic implementation object of type
// dojo.event.topic.TopicImpl
// topic:
// a unique, opaque string that names the topic
if(!this.topics[topic]){
this.topics[topic] = new this.TopicImpl(topic);
}
return this.topics[topic]; // a dojo.event.topic.TopicImpl object
}
this.registerPublisher = function(/*String*/topic, /*Object*/obj, /*String*/funcName){
// summary:
// registers a function as a publisher on a topic. Subsequent
// calls to the function will cause a publish event on the topic
// with the arguments passed to the function passed to registered
// listeners.
// topic:
// a unique, opaque string that names the topic
// obj:
// the scope to locate the function in
// funcName:
// the name of the function to register
var topic = this.getTopic(topic);
topic.registerPublisher(obj, funcName);
}
this.subscribe = function(/*String*/topic, /*Object*/obj, /*String*/funcName){
// summary:
// susbscribes the function to the topic. Subsequent events
// dispached to the topic will create a function call for the
// obj.funcName() function.
// topic:
// a unique, opaque string that names the topic
// obj:
// the scope to locate the function in
// funcName:
// the name of the function to being registered as a listener
var topic = this.getTopic(topic);
topic.subscribe(obj, funcName);
}
this.unsubscribe = function(/*String*/topic, /*Object*/obj, /*String*/funcName){
// summary:
// unsubscribes the obj.funcName() from the topic
// topic:
// a unique, opaque string that names the topic
// obj:
// the scope to locate the function in
// funcName:
// the name of the function to being unregistered as a listener
var topic = this.getTopic(topic);
topic.unsubscribe(obj, funcName);
}
this.destroy = function(/*String*/topic){
// summary:
// destroys the topic and unregisters all listeners
// topic:
// a unique, opaque string that names the topic
this.getTopic(topic).destroy();
delete this.topics[topic];
}
this.publishApply = function(/*String*/topic, /*Array*/args){
// summary:
// dispatches an event to the topic using the args array as the
// source for the call arguments to each listener. This is similar
// to JavaScript's built-in Function.apply()
// topic:
// a unique, opaque string that names the topic
// args:
// the arguments to be passed into listeners of the topic
var topic = this.getTopic(topic);
topic.sendMessage.apply(topic, args);
}
this.publish = function(/*String*/topic, /*Object*/message){
// summary:
// manually "publish" to the passed topic
// topic:
// a unique, opaque string that names the topic
// message:
// can be an array of parameters (similar to publishApply), or
// will be treated as one of many arguments to be passed along in
// a "flat" unrolling
var topic = this.getTopic(topic);
// if message is an array, we treat it as a set of arguments,
// otherwise, we just pass on the arguments passed in as-is
var args = [];
// could we use concat instead here?
for(var x=1; x<arguments.length; x++){
args.push(arguments[x]);
}
topic.sendMessage.apply(topic, args);
}
}
dojo.event.topic.TopicImpl = function(topicName){
// summary: a class to represent topics
this.topicName = topicName;
this.subscribe = function(/*Object*/listenerObject, /*Function or String*/listenerMethod){
// summary:
// use dojo.event.connect() to attach the passed listener to the
// topic represented by this object
// listenerObject:
// if a string and listenerMethod is ommitted, this is treated as
// the name of a function in the global namespace. If
// listenerMethod is provided, this is the scope to find/execute
// the function in.
// listenerMethod:
// Optional. The function to register.
var tf = listenerMethod||listenerObject;
var to = (!listenerMethod) ? dj_global : listenerObject;
return dojo.event.kwConnect({ // dojo.event.MethodJoinPoint
srcObj: this,
srcFunc: "sendMessage",
adviceObj: to,
adviceFunc: tf
});
}
this.unsubscribe = function(/*Object*/listenerObject, /*Function or String*/listenerMethod){
// summary:
// use dojo.event.disconnect() to attach the passed listener to the
// topic represented by this object
// listenerObject:
// if a string and listenerMethod is ommitted, this is treated as
// the name of a function in the global namespace. If
// listenerMethod is provided, this is the scope to find the
// function in.
// listenerMethod:
// Optional. The function to unregister.
var tf = (!listenerMethod) ? listenerObject : listenerMethod;
var to = (!listenerMethod) ? null : listenerObject;
return dojo.event.kwDisconnect({ // dojo.event.MethodJoinPoint
srcObj: this,
srcFunc: "sendMessage",
adviceObj: to,
adviceFunc: tf
});
}
this._getJoinPoint = function(){
return dojo.event.MethodJoinPoint.getForMethod(this, "sendMessage");
}
this.setSquelch = function(/*Boolean*/shouldSquelch){
// summary:
// determine whether or not exceptions in the calling of a
// listener in the chain should stop execution of the chain.
this._getJoinPoint().squelch = shouldSquelch;
}
this.destroy = function(){
// summary: disconnects all listeners from this topic
this._getJoinPoint().disconnect();
}
this.registerPublisher = function( /*Object*/publisherObject,
/*Function or String*/publisherMethod){
// summary:
// registers the passed function as a publisher on this topic.
// Each time the function is called, an event will be published on
// this topic.
// publisherObject:
// if a string and listenerMethod is ommitted, this is treated as
// the name of a function in the global namespace. If
// listenerMethod is provided, this is the scope to find the
// function in.
// publisherMethod:
// Optional. The function to register.
dojo.event.connect(publisherObject, publisherMethod, this, "sendMessage");
}
this.sendMessage = function(message){
// summary: a stub to be called when a message is sent to the topic.
// The message has been propagated
}
}