example of mixing pub-su

mixin.js

// utilizes the browser eventsystem
// usefull in cases where you need communication between independent components
// registered events are automatically removed onunload with preserving any other onunload handler
var eventsMixin = function(target) {
	
	var _subscriptions = [];

    target.broadcast = function(type, payload) {
        var ev = new CustomEvent(type, {
            detail: payload,
            bubbles: true,
            cancelable: true
        });
        document.dispatchEvent(ev);
    };

    target.subscribe = function(type, callback, capture) {
    	_subscriptions.push([type, callback, capture]);
        document.addEventListener(type, callback, capture || false);
    };

    target.ignore = function(type, callback, capture) {
        _subscriptions.splice(_subscriptions.indexOf([type, callback, capture]), 1);
        document.removeEventListener(type, callback, capture || false);
    };

	// save a reference to a possible present unload method
	var _savedUnload = (target.onunload)? target.onunload : null;
	
	target.onunload = function() {
		while (_subscriptions.length) {
			document.removeEventListener.apply(document, _subscriptions.pop());
		}
		_savedUnload && _savedUnload();
	};

	return target;
};



var obervableObject = eventsMixin({});

var component1 = {
  controller: function(){
    observable.subscribe('myFancyEvent',function(e) {
      
    });
    
    observable.broadcast('myOtherEvent', 'data');
  }
}

var component2 = {
  controller: function(){
    observable.subscribe('myOtherEvent',function(e) {
      
    });
    
    observable.broadcast('myFancyEvent', 'data');
  }
}

observable.subscribe

Where is observable defined?