Book Image

Angular Services

By : Sohail Salehi
Book Image

Angular Services

By: Sohail Salehi

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

Components - the reusable objects


Components in Angular 2 are building blocks that address and provide solutions for different concerns in a web app. If we can solve one problem in one component, it means we can use that same component later in other parts of the current project or other projects. They are usually used to handle a part of a view (an HTML template). So if we create a component for a progress bar, we can use it later anywhere in the project where we need it. We can use components in other projects as well. For example, a component for a navigation bar that is created in one project, can be imported and be used in other projects in the future.

Components are basically nothing more than a class, with a bunch of methods, properties, and other usual codes. Inside the seed project that we set up in the previous chapter, open the src/app/about/about.ts file, and observe the code:

// src/app/about/about.ts 
import {Component} from '@angular/core'; 
@Component({ 
  selector: 'about...