Book Image

Mastering TypeScript 3 - Third Edition

By : Nathan Rozentals
Book Image

Mastering TypeScript 3 - Third Edition

By: Nathan Rozentals

Overview of this book

TypeScript is both a language and a set of tools to generate JavaScript. It was designed by Anders Hejlsberg at Microsoft to help developers write enterprise-scale JavaScript. Starting with an introduction to the TypeScript language, before moving on to basic concepts, each section builds on previous knowledge in an incremental and easy-to-understand way. Advanced and powerful language features are all covered, including asynchronous programming techniques, decorators, and generics. This book explores many modern JavaScript and TypeScript frameworks side by side in order for the reader to learn their respective strengths and weaknesses. It will also thoroughly explore unit and integration testing for each framework. Best-of-breed applications utilize well-known design patterns in order to be scalable, maintainable, and testable. This book explores some of these object-oriented techniques and patterns, and shows real-world implementations. By the end of the book, you will have built a comprehensive, end-to-end web application to show how TypeScript language features, design patterns, and industry best practices can be brought together in a real-world scenario.
Table of Contents (16 chapters)
Free Chapter
TypeScript Tools and Framework Options


Decorators in TypeScript provide a way of programmatically tapping into the process of defining a class. Remember that a class definition describes the shape of a class. In other words, a class definition describes what properties a class has, and what methods it defines. It is only when a class is instantiated, that is, an instance of the class is created, that these properties and methods become available.

Decorators, however, allow us to inject code into the actual definition of a class. Decorators can be used on class definitions, class properties, class functions, and even method parameters. The concept of decorators exists in other programming languages, and are called attributes in C#, or annotations in Java.

In this section, we will explore what decorators are, how they are defined, and how they can be used. We will look at class, property, function, and method...