Sams Teach Yourself Node.js in 24 Hours

Hour 23. Creating Middleware with Connect

What You’ll Learn in This Hour:

• What Middleware is

• How you can use Middleware with Connect and Express

• What you can use Middleware for in Connect and Express applications

• What Middleware can offer developers

What Is Middleware?

In the context of Node.js, Middleware is a way to filter a request and response in your application by adding a thin layer between the client and your application logic (see Figure 23.1). It provides a simple way to separate concerns within your application and can lead to more maintainable code, a better security model, and code reuse across projects. The idea is relatively simple, but it offers a great deal of power and flexibility to developers.

Figure 23.1. How Middleware ...