Book Image

Angular 2 Cookbook

By : Patrick Gillespie, Matthew Frisbie
Book Image

Angular 2 Cookbook

By: Patrick Gillespie, Matthew Frisbie

Overview of this book

Angular 2 introduces an entirely new way to build applications. It wholly embraces all the newest concepts that are built into the next generation of browsers, and it cuts away all the fat and bloat from Angular 1. This book plunges directly into the heart of all the most important Angular 2 concepts for you to conquer. In addition to covering all the Angular 2 fundamentals, such as components, forms, and services, it demonstrates how the framework embraces a range of new web technologies such as ES6 and TypeScript syntax, Promises, Observables, and Web Workers, among many others. This book covers all the most complicated Angular concepts and at the same time introduces the best practices with which to wield these powerful tools. It also covers in detail all the concepts you'll need to get you building applications faster. Oft-neglected topics such as testing and performance optimization are widely covered as well. A developer that reads through all the content in this book will have a broad and deep understanding of all the major topics in the Angular 2 universe.
Table of Contents (18 chapters)
Angular 2 Cookbook
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Dedication
Preface

Understanding and implementing basic Promises


Promises are very useful in many of the core aspects of Angular. Although they are no longer bound to the core framework service, they still manifest themselves throughout Angular's APIs. The implementation is considerably simpler than Angular 1, but the main rhythms have remained consistent.

Note

You can refer to the code, links, and a live example of this at http://ngcookbook.herokuapp.com/5195 .

Getting ready

Before you start using promises, you should first understand the problem they are trying to solve. Without worrying too much about the internals, you can classify the concept of a Promise into three distinct stages:

  • Initialization: I have a piece of work that I want to accomplish, and I want to define what should happen when this work is completed. I do not know whether this work will be ever completed; also, the work may either fail or succeed.

  • Pending: I have started the work, but it has not been completed yet.

  • Completed: The work is finished...