The Ultimate Guide to Asynchronous Node.js JavaScript with ES2015/2016 Promises, Generators, and More

Are you tired of writing Node.js apps that are slow and unresponsive? Do you want to take advantage of the latest features in JavaScript to make your code more elegant and efficient? Look no further - this article will guide you through the world of asynchronous programming in Node.js using the power of ES2015/2016 Promises and Generators.

What is Asynchronous Programming?

Before we dive into the specifics of Node.js and ES2015/2016, let's quickly review what asynchronous programming is. In traditional synchronous programming, each task is executed one after the other, blocking the execution until a task is completed. This means that if your code relies on external resources, such as a database or an API, it will be waiting for a response before moving on to the next task.

Asynchronous programming, on the other hand, allows your code to move on to the next task without waiting for a response. This allows for faster and more efficient execution, as other tasks can be performed while waiting for responses from external resources. Node.js is built on asynchronous programming, making it ideal for building scalable web applications and handling thousands of concurrent connections.

Asynchronous Node.js/JavaScript with ES-2015/2016 Promises, Generators and Async/Await

by David Herron(Kindle Edition)

5 out of 5

Language	:	English
File size	:	963 KB
Text-to-Speech	:	Enabled
Enhanced typesetting	:	Enabled
Print length	:	193 pages
Lending	:	Enabled
Screen Reader	:	Supported

FREE

ES2015/2016 Promises: The Foundation of Asynchronous Programming

ES2015/2016 introduced Promises, a special syntax for handling asynchronous operations. Promises are objects that represent the eventual completion (or failure) of an asynchronous operation. They allow you to write cleaner and more readable code by avoiding the callback hell that can occur with traditional asynchronous programming.

A Promise can be in one of three states: pending, fulfilled, or rejected. When a Promise is fulfilled, it means the asynchronous operation has completed successfully and a value is available. When a Promise is rejected, it means the asynchronous operation has failed and an error message is available.

Using Promises in Node.js is as simple as creating a new Promise object and attaching a callback function to it. The callback function takes two parameters: one for handling the fulfilled state and one for handling the rejected state. This makes error handling much easier, as you can simply attach a catch callback function to handle any errors that occur during the execution of your code.

ES2015/2016 Generators: Simplifying Control Flow

ES2015/2016 also introduced Generators, which are functions that can be paused and resumed on demand. Generators allow you to write asynchronous code in a synchronous-like manner, simplifying control flow and making your code more readable and easier to maintain.

Generators are defined using the function* syntax, and they use the yield keyword to pause and resume execution. By combining Generators with Promises, you can create a powerful control flow mechanism that allows you to write code that is both elegant and efficient.

Working with Asynchronous Libraries in Node.js

Asynchronous programming in Node.js is made even easier with the help of various libraries and frameworks. These libraries provide additional functionality and abstractions that make it easier to work with asynchronous code.

Some popular libraries for asynchronous programming in Node.js include:

• Async
• Bluebird
• Q
• Co

These libraries provide additional methods and utilities for working with Promises and Generators, making it easier to handle complex asynchronous tasks. They also often provide performance improvements over the built-in asynchronous functions in Node.js.

Asynchronous programming in Node.js using ES2015/2016 Promises and Generators is a powerful technique for building fast and responsive web applications. By taking advantage of these features, you can write cleaner and more elegant code that is easier to maintain and debug.

In this article, we have explored the basics of asynchronous programming, learned about ES2015/2016 Promises and Generators, and discovered some popular libraries for working with asynchronous code in Node.js.

So what are you waiting for? Start upgrading your Node.js apps today with the power of asynchronous programming!

Asynchronous Node.js/JavaScript with ES-2015/2016 Promises, Generators and Async/Await

by David Herron(Kindle Edition)

5 out of 5

Language	:	English
File size	:	963 KB
Text-to-Speech	:	Enabled
Enhanced typesetting	:	Enabled
Print length	:	193 pages
Lending	:	Enabled
Screen Reader	:	Supported

FREE

ECMAScript 2015, 2016 and beyond are adding powerful new features to our beloved programming language. Asynchronous programming support with Promises, Generators and the async/await proposal allow us to write asynchronous code that's clean and normal looking. We can dispense with ugly boilerplate required when using asynchronous helper libraries. Inside correctly constructed functions, Generators and Async Functions, our asynchronous code looks and acts like regular synchronous code, meaning we can easily write normal loops containing asynchronous code.

It's a breath of fresh air, that not only looks right, but error reporting is vastly improved, which should improve code reliability.

This book walks you through the new asynchronous programming features in ES-2015, ES-2016 and the proposed async/await feature. The first half covers basic coding constructs, showing how to implement several looping constructs using the "async" library, Promises, Generators, and the proposed async/await feature. The second half of the book takes an in-depth look at using these features in production code. All through the book examples are given with real working code, along with comprehensive discussions of how the code works.

Node.js is the primary JavaScript platform used in the book for ease of demonstrating the concepts. We also show how to implement everything in modern browsers. Because the features are not available on all JavaScript engines, the book demonstrates how to use Babel to transpile/rewrite the code to run as ES-5 compliant JavaScript.

About the Author: David Herron is a software engineer and writer living and working in Silicon Valley for over 25 years. His software career spans several generations of the Internet, including a stint of over 10 years in the Java SE team at Sun Microsystems. In the mid-90's he helped to port Internet Explorer 3 to Unix. His Node.js use began while working on Yahoo's Manhattan/Mojito platform for hosting Node.js applications. His book, Node.js Web Development, is in its third edition.