Book Image

Essential Angular

By : Victor Savkin, Jeff Cross
Book Image

Essential Angular

By: Victor Savkin, Jeff Cross

Overview of this book

Essential Angular is a concise, complete overview of the key aspects of Angular, written by two Angular core contributors. The book covers the framework's mental model, its API, and the design principles behind it. This book is fully up to date with the latest release of Angular. Essential Angular gives you a strong foundation in the core Angular technology. It will help you put all the concepts into the right places so you will have a good understanding of why the framework is the way it is. Read this book after you have toyed around with the framework, but before you embark on writing your first serious Angular application. This book covers concepts such as the differences between Just-In-Time (JIT) and Ahead-Of-Time (AOT) compilation in Angular, alongside NgModules, components and directives. It also goes into detail on Dependency Injection and Change Detection: essential skills for Angular developers to master. The book finishes with a look at testing, and how to integrate different testing methodologies in your Angular code.
Table of Contents (11 chapters)


Now, when we have understood how we had separated the two phases, let's talk about why we did it.


First, using change detection only for updating the view state limits the number of places where the application model can be changed. In this example, it can happen only in the rateTalk function. A watcher cannot "automagically" update it. This makes ensuring invariants easier, which makes code easier to troubleshoot and refactor.

Second, it helps us understand the view state propagation. Consider what we can say about the talk component just by looking at it in isolation. Since we use immutable data, we know that as long as we do not do talk= in the Talk component, the only way to change what the component displays is by updating...