text: 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);
  			// make local copy of listener array so it is immutable during processing
  			var lls;
  			//>>includeStart("connectRhino", kwArgs.profileProperties.hostenvType == "rhino");
  			if(!dojo.isRhino){
  			//>>includeEnd("connectRhino");
  				//>>includeStart("connectBrowser", kwArgs.profileProperties.hostenvType != "rhino");
  				lls = [].concat(ls);
  				//>>includeEnd("connectBrowser");
  			//>>includeStart("connectRhino", kwArgs.profileProperties.hostenvType == "rhino");
  			}else{
  				// FIXME: in Rhino, using concat on a sparse Array results in a dense Array.
  				// IOW, if an array A has elements [0, 2, 4], then under Rhino, "concat [].A"
  				// results in [0, 1, 2, 3, 4], where element 1 and 3 have value 'undefined'
  				// "A.slice(0)" has the same behavior.
  				lls = [];
  				for(var i in ls){
  					lls[i] = ls[i];
  				}
  			}
  			//>>includeEnd("connectRhino");
  
  			// invoke listeners after target function
  			for(var i in lls){
  				if(!(i in ap)){
  					lls[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
  };
  