easyevents

Adds event capabilities to any constructor

Volo

Install with volo:

volo add Kreata/easyevents/v0.1.0

AMD

Require easyevents.js as easyevents

Global context

Include file easyevents.js on the page.

<script src="easyevents.js"></script>

This exposes global variable easyevents

Usage

Run easyevents.apply(this) in the constructor function and easyevents.extend(ConstructorName) outside of it.

function MyConstructor(){
    easyevents.apply(this);
}
easyevents.extend(MyConstructor);

The constructor inherits the following methods

• emit (eventName[, param1, param2, ..., paramN]) - emits selected event
• on (alias for addListener) (eventName, handler) - Sets up a handler for an event
• removeListener (eventName, handler) - Removes a handler

Example

The following script defines an emitter that emits an incrementing number every second.

function MyConstructor(){
    easyevents.apply(this);
}
easyevents.extend(MyConstructor);

var instance = new MyConstructor(),
    i = 0,
    handler = function(val){
        console.log("Received nr %s", val);  
    };

instance.on("counter", handler);

var interval = setInterval(function(){
    console.log("Emit nr %s", ++i);
    instance.emit("counter", i);
    if(i >= 4){
        instance.removeListener("counter", handler);
    }
    if(i >= 6){
        clearInterval(interval);
    }
}, 1000);

The result of such a script should be:

"Emit nr 1"
"Received nr 1"
"Emit nr 2"
"Received nr 2"
"Emit nr 3"
"Received nr 3"
"Emit nr 4"
"Received nr 4" <- Event handler is cleared after 4
"Emit nr 5"
"Emit nr 6" <- Interval is cleared after 6

License

MIT