Book Image

Express Web Application Development

By : Hage Yaaapa
Book Image

Express Web Application Development

By: Hage Yaaapa

Overview of this book

Express is a minimal and flexible node.js web application framework, providing a robust set of features for building single and multi-page, and hybrid web applications. It provides a thin layer of features fundamental to any web application, without obscuring features that developers know and love in node.js. "Express Web Application Development" is a comprehensive guide for those looking to learn how to use the Express web framework for web application development. Starting with the initial setup of the Express web framework, "Express Web Application Development" helps you to understand the fundamentals of the framework. By the end of "Express Web Application Development", you will have acquired enough knowledge and skills to create production-ready Express apps. All of this is made possible by the incremental introduction of more advanced topics, starting from the very essentials. On the way to mastering Express for application development, we teach you the more advanced topics such as routes, views, middleware, forms, sessions, cookies and various other aspects of configuring an Express application. Jade; the recommended HTML template engine, and Stylus; the CSS pre-processor for Express, are covered in detail. Last, but definitely not least, Express Web Application Development also covers practices and setups that are required to make Express apps production-ready.
Table of Contents (15 chapters)
Express Web Application Development
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

How to handle routes


When a request is made to the server, which matches a route definition, the associated callback functions kick in to process the request and send back a response. These callback functions are responsible for the dynamic behavior of the app; without them routes would simply be dumb interfaces that do nothing at all.

So far, we have been dealing with a single callback function for a route, but a route can have more than one callback function.

As mentioned earlier, the Express routing system is also built around the middleware concept—each route handler has the capability to send a response or pass on the request to the next route-handling middleware in the current or the next matching route.

All of a sudden route handling sounds a little more complicated than what we assumed earlier, doesn't it? Let's find out if it is so.

By now, we are all familiar with how a route definition looks like:

app.get('/', function(req, res) {
  res.send('welcome');
});

We have been using a single...