Book Image

Learning Angular - Fourth Edition

By : Aristeidis Bampakos, Pablo Deeleman
Book Image

Learning Angular - Fourth Edition

By: Aristeidis Bampakos, Pablo Deeleman

Overview of this book

As Angular continues to reign as one of the top JavaScript frameworks, more developers are seeking out the best way to get started with this extraordinarily flexible and secure framework. Learning Angular, now in its fourth edition, will show you how you can use it to achieve cross-platform high performance with the latest web techniques, extensive integration with modern web standards, and integrated development environments (IDEs). The book is especially useful for those new to Angular and will help you to get to grips with the bare bones of the framework to start developing Angular apps. You'll learn how to develop apps by harnessing the power of the Angular command-line interface (CLI), write unit tests, style your apps by following the Material Design guidelines, and finally, deploy them to a hosting provider. Updated for Angular 15, this new edition covers lots of new features and tutorials that address the current frontend web development challenges. You’ll find a new dedicated chapter on observables and RxJS, more on error handling and debugging in Angular, and new real-life examples. By the end of this book, you’ll not only be able to create Angular applications with TypeScript from scratch, but also enhance your coding skills with best practices.
Table of Contents (17 chapters)
Other Books You May Enjoy

Providing dependencies across the application

The Angular framework offers an actual injector that can introspect the tokens used to annotate the parameters in the constructor of an Angular artifact.

It returns a singleton instance of the type represented by each dependency so that we can use it straight away in the implementation of our class. The injector maintains a list of all dependencies that an Angular application needs. When a component or other artifact wants to use a dependency, the injector first checks to see if it has already created an instance of this dependency. If not, it creates a new one, returns it to the component, and keeps a copy for further use. The next time the same dependency is requested, it returns the copy previously created. But how does the injector know which dependencies an Angular application needs?

When we create an Angular service, we use the providedIn property of the @Injectable decorator to define how it is provided to the application...