Mastering JavaScript

Chapter 5
var TweetFollower = {
update : function() {
console.log( '"Following this tweet - ', arguments );
}
};
Both these observers will have one update() method that will be called by the
Subject.notify() method. Now we can actually add these observers to the
Subject via Tweeter's interface:
var tweetApp = new Tweeter();
tweetApp.addObserver( TweetUpdater );
tweetApp.addObserver( TweetFollower );
tweetApp.fetchTweets();
tweetApp.removeObserver(TweetUpdater);
tweetApp.removeObserver(TweetFollower);
This will result in the following output:
Added observer
Added observer
Updated Tweet - { '0': [ { tweet: 'This is one nice observer' } ] }
"Following this tweet - { '0': [ { tweet: 'This is one nice
observer' } ] }
Removed Observer
Removed Observer
This is a basic implementation to illustrate the idea of the observer pattern.
JavaScript Model-View-* patterns
Model-View-Controller (MVC), Model-View-Presenter (MVP), and Model-View-
ViewModel (MVVM) have been popular with server applications, but in recent
years JavaScript applications are also using these patterns to structure and manage
large projects. Many JavaScript frameworks have emerged that support MV*
patterns. We will discuss a few examples using Backbone.js.
Model-View-Controller
MVC is a popular structural pattern where the idea is to divide an application into
three parts so as to separate the internal representations of information from the
presentation layer. MVC consists of components. The model is the application object,
view is the presentation of the underlying model object, and controller handles the
way in which the user interface behaves, depending on the user interactions.
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