Book Image

Node.js Design Patterns

By : Mario Casciaro
Book Image

Node.js Design Patterns

By: Mario Casciaro

Overview of this book

Node.js is a massively popular software platform that lets you use JavaScript to easily create scalable server-side applications. It allows you to create efficient code, enabling a more sustainable way of writing software made of only one language across the full stack, along with extreme levels of reusability, pragmatism, simplicity, and collaboration. Node.js is revolutionizing the web and the way people and companies create their software. In this book, we will take you on a journey across various ideas and components, and the challenges you would commonly encounter while designing and developing software using the Node.js platform. You will also discover the "Node.js way" of dealing with design and coding decisions. The book kicks off by exploring the fundamental principles and components that define the platform. It then shows you how to master asynchronous programming and how to design elegant and reusable components using well-known patterns and techniques. The book rounds off by teaching you the various approaches to scale, distribute, and integrate your Node.js application.
Table of Contents (16 chapters)
Node.js Design Patterns
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Template


The next pattern that we are going to analyze is called Template and it also has a lot in common with the Strategy pattern. Template consists of defining an abstract pseudo class that represents the skeleton of an algorithm where some of its steps are left undefined. Subclasses can then fill the gaps in the algorithm by implementing the missing steps, called template methods. The intent of this pattern is making it possible to define a family of classes that are all variations of a similar algorithm. The following UML diagram shows the structure that we just described:

The three concrete classes shown in the previous diagram, extend Template and provide an implementation for templateMethod(), which is abstract or pure virtual, to use the C++ terminology; in JavaScript this means that the method is left undefined or is assigned to a function that always throws an exception, indicating the fact that the method has to be implemented. The Template pattern can be considered more classically...