Book Image

Mastering Node.js

By : Sandro Pasquali
Book Image

Mastering Node.js

By: Sandro Pasquali

Overview of this book

Node.js is a modern development stack focused on providing an easy way to build scalable network software. Backed by a growing number of large companies and a rapidly increasing developer base, Node is revolutionizing the way that software is being built today. Powered by Google's V8 engine and built out of C++ modules, this is a JavaScript environment for the enterprise.Mastering Node.js will take the reader deep into this exciting development environment. Beginning with a comprehensive breakdown of its innovative non-blocking evented design, Node's structure is explained in detail, laying out how its blazingly fast I/O performance simplifies the creation of fast servers, scalable architectures, and responsive web applications.Mastering Node.js takes you through a concise yet thorough tour of Node's innovative evented non-blocking design, showing you how to build professional applications with the help of detailed examples.Learn how to integrate your applications with Facebook and Twitter, Amazon and Google, creating social apps and programs reaching thousands of collaborators on the cloud. See how the Express and Path frameworks make the creation of professional web applications painless. Set up one, two, or an entire server cluster with just a few lines of code, ready to scale as soon as you're ready to launch. Move data seamlessly between databases and file systems, between clients, and across network protocols, using a beautifully designed, consistent, and predictable set of tools.Mastering Node.js contains all of the examples and explanations you'll need to build applications in a short amount of time and at a low cost, running on a scale and speed that would have been nearly impossible just a few years ago.
Table of Contents (20 chapters)
Mastering Node.js
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Listening for file changes


Let's apply what we've learned. The goal is to create a server that a client can connect to and receive updates from Twitter. We will first create a process to query Twitter for any messages with the hashtag #nodejs, and writes any found messages to a tweets.txt file in 140-byte chunks. We will then create a network server that broadcasts these messages to a single client. Those broadcasts will be triggered by write events on the tweets.txt file. Whenever a write occurs, 140-byte chunks are asynchronously read from the last known client read pointer. This will happen until we reach the end of the file, broadcasting as we go. Finally, we will create a simple client.html page, which asks for, receives, and displays these messages.

While this example is certainly contrived, it demonstrates:

  • Listening to the filesystem for changes and responding to those events

  • Using data stream events for reading and writing files

  • Responding to network events

  • Using timeouts for polling...