Book Image

Angular Cookbook

By : Muhammad Ahsan Ayaz
Book Image

Angular Cookbook

By: Muhammad Ahsan Ayaz

Overview of this book

The Angular framework, powered by Google, is the framework of choice for many web development projects built across varying scales. It’s known to provide much-needed stability and a rich tooling ecosystem for building production-ready web and mobile apps. This recipe-based guide enables you to learn Angular concepts in depth using a step-by-step approach. You’ll explore a wide range of recipes across key tasks in web development that will help you build high-performance apps. The book starts by taking you through core Angular concepts such as Angular components, directives, and services to get you ready for building frontend web apps. You’ll develop web components with Angular and go on to cover advanced concepts such as dynamic components loading and state management with NgRx for achieving real-time performance. Later chapters will focus on recipes for effectively testing your Angular apps to make them fail-safe, before progressing to techniques for optimizing your app’s performance. Finally, you’ll create Progressive Web Apps (PWA) with Angular to provide an intuitive experience for users. By the end of this Angular book, you’ll be able to create full-fledged, professional-looking Angular apps and have the skills you need for frontend development, which are crucial for an enterprise Angular developer.
Table of Contents (15 chapters)

Creating a singleton service using providedIn

In this recipe, you'll learn several tips on how to ensure your Angular service is being used as a singleton. This means that there will only be one instance of your service in the entire application. Here, we'll use a couple of techniques, including the providedIn: 'root' statement and making sure we only provide the service once in the entire app by using the @Optional() and @SkipSelf() decorators.

Getting ready

The project for this recipe resides in the chapter03/start_here/ng-singleton-service path. Perform the following steps:

  1. Open the project in Visual Studio Code.
  2. Open the Terminal, and run npm install to install the dependencies of the project.
  3. Once done, run ng serve -o.

    This should open the app in a new browser tab. You should see something similar to the following screenshot:

Figure 3.7 – The ng-singleton-service app running on http://localhost:4200...