Book Image

Angular Services

Book Image

Angular Services

Overview of this book

A primary concern with modern day applications is that they need to be dynamic, and for that, data access from the server side, data authentication, and security are very important. Angular leverages its services to create such state-of-the-art dynamic applications. This book will help you create and design customized services, integrate them into your applications, import third-party plugins, and make your apps perform better and faster. This book starts with a basic rundown on how you can create your own Angular development environment compatible with v2 and v4. You will then use Bootstrap and Angular UI components to create pages. You will also understand how to use controllers to collect data and populate them into NG UIs. Later, you will then create a rating service to evaluate entries and assign a score to them. Next, you will create "cron jobs" in NG. We will then create a crawler service to find all relevant resources regarding a selected headline and generate reports on it. Finally, you will create a service to manage accuracy and provide feedback about troubled areas in the app created. This book is up to date for the 2.4 release and is compatible with the 4.0 release as well, and it does not have any code based on the beta or release candidates.
Table of Contents (15 chapters)
Angular Services
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

What is a service and why do we need them?


Sometimes implementing business logic in a web application requires fetching some data from other resources. In other words, we don't need any template; we are only interested in specific data.

For example, the Collector component is in charge of collecting news from various sources. To implement this business logic, we can add a few methods inside the component class and directly feed the results to the component template. But this solution is not ideal. First, the number of lines in the component class will grow unnecessarily. That will violate modularity rules and Angular best practices - keeping classes small. As a result, it will force higher maintenance costs in the future.

Moreover, when we need the same logic in another part of the application (or in a totally different application) we can't use it because it is coupled to a specific component class itself.

The better approach is to implement that business logic in another class - called a...