Chapter 3. The Publish/Subscribe Pattern

In this chapter, we will showcase the Publish/Subscribe Pattern, a design pattern quite similar to the Observer Pattern but with a more distinct role that is a better fit for more complex use cases. We will see how it differs from the Observer Pattern and how jQuery adopted some of its concepts and brought them to its Observer Pattern implementation.

Later, we will proceed and rewrite our previous chapter's example using this pattern. We will use this pattern's benefits to add some extra features and also reduce the coupling of our code with the elements of the web page.

In this chapter, we will:

• Introduce the Publish/Subscribe Pattern
• Learn how it differs and what advantages it has over the Observer Pattern
• Learn how jQuery brings some of its features to its methods
• Learn how to emit custom events with jQuery
• Rewrite and extend the example from Chapter 2, The Observer Pattern, using this pattern