Another version of my "Signals" event system.

SignalsV2.js

// SignalsV2.js

(function () {
	
	'use strict';
	
	function Signals () {};
	var exports = this,
		signalsMap = {},
		_signalRtnVal_ = {},
		signals = Signals.prototype;
  
	function isAry(obj) {
		return (obj.constructor === Array);
	};
	
	function _setSignalOnceRV (val) {
		_signalRtnVal_ = val;
		return this;
	};
	
	function _getSignalOnceRV () {
		if (_signalRtnVal_) {
			return _signalRtnVal_;
		}
		else {
			return true;
		}
	};
		
	function wen(nam, func) {
		if (!signalsMap) {
			signalsMap = {};
		}
		if (!signalsMap[nam]) {
			signalsMap[nam] = func;
		} 
		else if (isAry(signalsMap[nam])) {
			signalsMap[nam].push(func);
		} 
		else {
			signalsMap[nam] = [signalsMap[nam], func];
		}	
		return this;
	};
	  
	signals.signaled = function(nam, func) {
		return wen(nam, function(evnt){
			return func(evnt);
		});
	};

	signals.dropReceivers = function (nam) {
		if (!nam) {
			signalsMap = {};
			return this;
		}
		if (signalsMap && signalsMap[nam]) {
			signalsMap[nam] = null;
		}
		return this;
	};
	  
	signals.receiverObjects = function (nam) {
		var recvrLst = this.receivers(nam), rspns;	
		if (isAry(recvrLst)) {
			rspns = {};
			rspns[nam] = recvrLst;
		}	
		return rspns || recvrLst;
	};
	  
	signals.receivers = function (nam) {
		if (!signalsMap) {
			signalsMap = {};
		}
		if (!signalsMap[nam]) {
			signalsMap[nam] = [];
		}
		if (!isAry(signalsMap[nam])) {
			signalsMap[nam] = [signalsMap[nam]];
		}
		return signalsMap[nam];
	};
		
	signals.addReceiver = function(nam, func) {
		return wen(nam, function(evnt){
			return func(evnt);
		});
	};
	
	signals.signaledOnce = function (nam, func) {
		var slf = this;
		function onit () {
			slf.dropReceiver(nam, wen);
			func.apply(this, args);
		};
		wen.receiver = func;
		this.onit(nam, wen);	
		return this;
	};
	
	signals.receiveOnce = function(nam, func) {
		return signaledOnce(nam, function(evnt) {
			return func(evnt);
		});
	};

	signals.dropReceiver = function (nam, func) {
		if (signalsMap && signalsMap[nam]) {
			var sigLst = signalsMap[nam];	
			if (isAry(sigLst)) {
				var idx = -1;
				for (var i = 0, l = sigLst.length; i < l; i++) {
					if (sigLst[i] === func || (sigLst[i].receiver && sigLst[i].receiver === func)) {
						idx = i;
						break;
					}
				}
				if (idx < 0) {
					return this;
				}
				sigLst.splice(idx, 1);
				if (!sigLst.length) {
					delete signalsMap[nam];
				}
			} 
			else if (sigLst === func || (sigLst.receiver && sigLst.receiver === func)) {
				delete signalsMap[nam];
			}
		}
		return this;
	};
	 
	signals.signal = function (nam, args) {
		var recvrLst = this.receiverObjects(nam),
		k, recvr, i, rspns;
		for (k in recvrLst ) {
			if (recvrLst.hasOwnProperty(k)) {
				i = recvrLst[k].length;		
				while (i--) {
					recvr = recvrLst[k][i];
					if (recvr.signaledOnce === true) {
						this.dropReceiver(nam, recvr);
					}	
					rspns = recvr.call(this, args || []);
					if (rspns === _getSignalOnceRV()) {
						this.dropReceiver(nam, recvr);
					}
				}
			}
		}
		return this;
	};

	if (typeof module === 'object' && module.exports) {
		module.exports = Signals;
	}
	else if (typeof define === 'function' && define.amd) {
		define(function () {
			return Signals;
		});
	}
	else {
		exports.Signals = Signals;
	}
	
}.call(this));