Welcome to the second part of this book and congratulations for coming here! Now that you know the basic principles and techniques of programming in JavaScript, it's time to go deeper and know much better about some advantages offered by the wonderful framework that is Aurelia. Our starting point in this chapter will be to understand what is a component and how we can manage its life cycle through events that are taking place in our application. Then, we will explore the dependencies injection, a well-known design pattern used by most popular frameworks such as Java EE, Spring, and Aurelia! Our main focus will be to explain how we can manage our DOM and dynamically display the data on the screen, configure routes to access certain functionalities in our application, and, of course, apply everything learned in our FIFA World Cup application. This chapter will cover a lot of very useful concepts, some of them are:

• Creating components
• Dependency Injection pattern
• Component's life cycle/events
• Data binding
• Aurelia router
• Testing components

Let's start!