deterministic-events-usage.js

//some deterministic event system, could be global or created with constructor
var events = new DeterministicEventSystem();

(function(){
    //This object only exists inside this IIFE, not outside it
    var myObject = {
        handler: function(event){
            console.log("handle event: " + event);
        }
    };

    //add a listener to events temporarily, for one block of code
    events.withListener("someEvent", myObject.handler, () => {
        //the following causes the handler above to be called, resulting in output on the console
        events.dispatchEvent("someEvent", {params:"someParams"});
    });
})();

//myObject is not registered as a listener anymore
//the following does not output anything on the console
events.dispatchEvent("someEvent", {params:"someParams"});

weak-events-usage.js

//some weak event system, could be global or created with constructor
var events = new WeakEventSystem();

(function(){
    //This object only exists inside this IIFE, not outside it
    var myObject = {
        handler: function(event){
            console.log("handle event: " + event);
        }
    };

    //add a listener to events, but events only has a weak reference to it
    events.addEventListener("someEvent", myObject.handler);
   
    //the following causes the handler above to be called, resulting in output on the console
    events.dispatchEvent("someEvent", {params:"someParams"});

})();

//myObject does not exist anymore
//the following does not output anything on the console
events.dispatchEvent("someEvent", {params:"someParams"});