Book Image

TypeScript Design Patterns

By : Vilic Vane
Book Image

TypeScript Design Patterns

By: Vilic Vane

Overview of this book

In programming, there are several problems that occur frequently. To solve these problems, there are various repeatable solutions that are known as design patterns. Design patterns are a great way to improve the efficiency of your programs and improve your productivity. This book is a collection of the most important patterns you need to improve your applications’ performance and your productivity. The journey starts by explaining the current challenges when designing and developing an application and how you can solve these challenges by applying the correct design pattern and best practices. Each pattern is accompanied with rich examples that demonstrate the power of patterns for a range of tasks, from building an application to code testing. We’ll introduce low-level programming concepts to help you write TypeScript code, as well as work with software architecture, best practices, and design aspects.
Table of Contents (15 chapters)
TypeScript Design Patterns
About the Author
About the Reviewer

Strategy Pattern

It's common that a program has similar outlines for processing different targets with different detailed algorithms. Strategy Pattern encapsulates those algorithms and makes them interchangeable within the shared outline.

Consider conflicting merging processes of data synchronization, which we talked about in Chapter 2, The Challenge of Increasing Complexity. Before refactoring, the code was like this:

if (type === 'value') { 
  // ... 
} else if (type === 'increment') { 
  // ... 
} else if (type === 'set') { 
  // ... 

But later we found out that we could actually extract the same outlines from different phases of the synchronization process, and encapsulate them as different strategies. After refactoring, the outline of the code became as follows:

let strategy = strategies[type]; 

We get a lot of ways to compose and organize those strategy objects or classes sometimes in JavaScript. A possible structure...