JavaScript observer coding pattern implementation

new Observable() returns Observable object

trigger(namespace, data)

Trigger event on given namespace, namespace can be separated by ":"

• @param {string} namespace Event namespace (which we want to trigger)
• @param {object} data Data for event callbacks

addEventListener(namespace, callback, callback_object)

Listen on events distinguished by namespace

• @param {string} namespace Event namespace (which we want to trigger)
• @param {object} callback Callback which will be triggered on event
• @param {callback_object} Object which will be "this" inside callback

removeEventListener(namespace, callback)

Remove triggered callback from event namespace

• @param {string} namespace Event namespace
• @param {object} callback Callback which we want to remove from event namespace

var observable = new Observable();
observable.addEventListener("change:title", function(data) {
	console.log("title has changed to ", data.title);
});
observable.trigger("change:title", { title: "foo" }); // "title has changed to foo"
observable.trigger("change", { title: "bar" }); // "title has changed to bar"

var observable = new Observable();
var anotherHandler = function() {
	console.log("I'm another handler");
};
var handler = function(data) {
    console.log("removing my friend");
    observable.removeEventListener("change:title", anotherHandler);
};
observable.addEventListener("change:title", handler);
observable.addEventListener("change:title", anotherHandler);
observable.trigger("change:title", { title: "moo" }); // "removing my friend"