Book Image

Scala Design Patterns - Second Edition

By : Ivan Nikolov
Book Image

Scala Design Patterns - Second Edition

By: Ivan Nikolov

Overview of this book

Design patterns make developers’ lives easier by helping them write great software that is easy to maintain, runs efficiently, and is valuable to the company or people concerned. You’ll learn about the various features of Scala and will be able to apply well-known, industry-proven design patterns in your work. The book starts off by focusing on some of the most interesting and latest features of Scala while using practical real-world examples. We will be learning about IDE’s and Aspect Oriented Programming. We will be looking into different components in Scala. We will also cover the popular "Gang of Four" design patterns and show you how to incorporate functional patterns effectively. The book ends with a practical example that demonstrates how the presented material can be combined in real-life applications. You’ll learn the necessary concepts to build enterprise-grade applications. By the end of this book, you’ll have enough knowledge and understanding to quickly assess problems and come up with elegant solutions.
Table of Contents (14 chapters)

The command design pattern

Sometimes in our applications, we might need to pass information to other objects about how to perform some action. Usually, this action will be executed at a later time based on some kind of event. The object that will execute our commands is called invoker, and it might not even be aware of the command it actually runs. It just knows about the interface, which means that it knows how to trigger the command. The command design pattern helps us to achieve this.

The purpose of the command design pattern is to encapsulate the information needed to perform an action at a later stage and pass this information to the object that will be running the actual code.

Usually, the command information will contain the object that owns the method, the method name, and the parameters that should be passed when invoking the method. The command design pattern is useful...