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

Generators


The ES6 specification introduces another mechanism that, besides other things, can be used to simplify the asynchronous control flow of our Node.js applications. We are talking about generators, also known as semi-coroutines. They are a generalization of subroutines, where there can be different entry points. In a normal function, in fact, we can have only one entry point, which corresponds to the invocation of the function itself. A generator is similar to a function, but in addition, it can be suspended (using the yield statement) and then resumed at a later time. Generators are particularly useful when implementing iterators, and this should ring a bell, as we have already seen how iterators can be used to implement important asynchronous control flow patterns such as sequential and limited parallel execution.

Note

In Node.js, generators are available starting from Version 0.11, but at the moment of writing, this feature is still not enabled by default and it's necessary to...