Managing state transitions is one of the hardest parts of building applications. This is especially true on the web, where you also need to ensure that the state is reflected in the URL. In addition, you might want to split applications into multiple bundles and load them on demand. Doing this transparently isn’t easy. The Angular router solves these problems. Using the router, you can declaratively specify application states, manage state transitions while taking care of the URL, and load bundles on demand. This book is a complete description of the Angular router written by its designer. It goes far beyond a how-to-get-started guide and talks about the library in depth. The mental model, design constraints, and the subtleties of the API-everything is covered. You’ll learn in detail how to use the router in your own applications. Predominantly, you’ll understand the inner workings of the router and how you can configure it to work with any edge cases you come across in your sites. Throughout the book, you’ll see examples from real-world use in the MailApp application. You can view the full source of this application and see how the router code works to manage the state of the application and define what is visible on screen. Reading this book will give you deep insights into why the router works the way it does and will make you an Angular router expert.