Using structures and closures for stateful handlers

Due to the sparse signatures of HTTP handler functions, it may seem tricky to add state to a handler. For example, there are a variety of ways to include a database connection. Two approaches to doing this are to pass in the state via closures, which is useful for achieving flexibility on a single handler, or by using a structure.

This recipe will demonstrate both. We'll use a struct controller to store a storage interface and create two routes with a single handler that are modified by an outer function.

How to do it...

The following steps cover the writing and running of your application:

1. From your Terminal or console application,createa new directory called~/projects/go-programming-cookbook/chapter8/controllers, and navigate to this directory.
2. Run the following command:

          $ go mod init github.com/PacktPublishing/Go-Programming-Cookbook-Second...