(function (root, factory) {
if(typeof exports === 'object' && typeof module === 'object')
module.exports = factory();
else if(typeof define === 'function' && define.amd)
define("EventBus", [], factory);
else if(typeof exports === 'object')
exports["EventBus"] = factory();
else
root["EventBus"] = factory();
})(this, function() {
var EventBusClass = {};
EventBusClass = function() {
this.listeners = {};
};
EventBusClass.prototype = {
addEventListener: function(type, callback, scope) {
var args = [];
var numOfArgs = arguments.length;
for(var i=0; i<numOfArgs; i++){
args.push(arguments[i]);
}
args = args.length > 3 ? args.splice(3, args.length-1) : [];
if(typeof this.listeners[type] != "undefined") {
this.listeners[type].push({scope:scope, callback:callback, args:args});
} else {
this.listeners[type] = [{scope:scope, callback:callback, args:args}];
}
},
removeEventListener: function(type, callback, scope) {
if(typeof this.listeners[type] != "undefined") {
var numOfCallbacks = this.listeners[type].length;
var newArray = [];
for(var i=0; i<numOfCallbacks; i++) {
var listener = this.listeners[type][i];
if(listener.scope == scope && listener.callback == callback) {
} else {
newArray.push(listener);
}
}
this.listeners[type] = newArray;
}
},
hasEventListener: function(type, callback, scope) {
if(typeof this.listeners[type] != "undefined") {
var numOfCallbacks = this.listeners[type].length;
if(callback === undefined && scope === undefined){
return numOfCallbacks > 0;
}
for(var i=0; i<numOfCallbacks; i++) {
var listener = this.listeners[type][i];
if((scope ? listener.scope == scope : true) && listener.callback == callback) {
return true;
}
}
}
return false;
},
dispatch: function(type, target) {
var event = {
type: type,
target: target
};
var args = [];
var numOfArgs = arguments.length;
for(var i=0; i<numOfArgs; i++){
args.push(arguments[i]);
};
args = args.length > 2 ? args.splice(2, args.length-1) : [];
args = [event].concat(args);
if(typeof this.listeners[type] != "undefined") {
var listeners = this.listeners[type].slice();
var numOfCallbacks = listeners.length;
for(var i=0; i<numOfCallbacks; i++) {
var listener = listeners[i];
if(listener && listener.callback) {
var concatArgs = args.concat(listener.args);
listener.callback.apply(listener.scope, concatArgs);
}
}
}
},
getEvents: function() {
var str = "";
for(var type in this.listeners) {
var numOfCallbacks = this.listeners[type].length;
for(var i=0; i<numOfCallbacks; i++) {
var listener = this.listeners[type][i];
str += listener.scope && listener.scope.className ? listener.scope.className : "anonymous";
str += " listen for '" + type + "'\n";
}
}
return str;
}
};
var EventBus = new EventBusClass();
return EventBus;
});
<!DOCTYPE html>
<html>
<head>
<title>Events</title>
<script type="text/javascript" language="javascript" src="js/EventBus.js"></script>
<script type="text/javascript" language="javascript">
window.onload = function() {
// ******************************************************************************************
function myFunction(event) {
console.log("myFunction type=" + event.type);
}
EventBus.addEventListener("my_function_event", myFunction);
EventBus.dispatch("my_function_event");
// ******************************************************************************************
console.log("\n");
var TestClass1 = function() {
this.className = "TestClass1";
this.callback = function(event) {
console.log(this.className + " = type:" + event.type + " / dispatcher:" + event.target.className);
}
};
var TestClass2 = function() {
this.className = "TestClass2";
this.dispatchOurEvent = function() {
EventBus.dispatch("callback_event", this);
}
};
var t1 = new TestClass1();
var t2 = new TestClass2();
EventBus.addEventListener("callback_event", t1.callback, t1);
t2.dispatchOurEvent();
// ******************************************************************************************
console.log("\n");
var TestClass1 = function() {
this.className = "TestClass1";
this.doSomething = function(event, param1, param2) {
console.log(this.className + ".doSomething");
console.log("type=" + event.type);
console.log("params=" + param1 + param2);
console.log("coming from=" + event.target.className);
}
};
var TestClass2 = function() {
this.className = "TestClass2";
this.ready = function() {
EventBus.dispatch("custom_event", this, "javascript events", " are really useful");
}
};
var t1 = new TestClass1();
var t2 = new TestClass2();
EventBus.addEventListener("custom_event", t1.doSomething, t1);
t2.ready();
// ******************************************************************************************
console.log("\n");
var winterHandler = function() {
console.log("arguments", arguments);
}
EventBus.addEventListener("let-it-snow", winterHandler, null, "and happy", "new year");
EventBus.dispatch("let-it-snow", null, "merry", "christmas");
EventBus.dispatch("let-it-snow", null, "merry", "christmas");
EventBus.dispatch("let-it-snow", null, "merry", "christmas");
}
</script>
</head>
<body>
<div id="console.log">
</div>
</body>
</html>
