Laravel: Up & Running, 3rd Edition

Chapter 10. Requests, Responses, and Middleware

We’ve already talked a bit about the Illuminate Request object. In Chapter 3, for example, you saw how you can typehint it in constructors to get an instance or use the request() helper to retrieve it, and in Chapter 7 we looked at how you can use it to get information about the user’s input.

In this chapter, you’ll learn more about what the Request object is, how it’s generated, what it represents, and what part it plays in your application’s lifecycle. We’ll also talk about the Response object and Laravel’s implementation of the middleware pattern.

Laravel’s Request Lifecycle

Every request coming into a Laravel application, whether generated by an HTTP request or a command-line interaction, is immediately converted into an Illuminate Request object, which then crosses many layers and ends up being parsed by the application itself. The application then generates an Illuminate Response object, which is sent back out across those layers and finally returned to the end user.

This request/response lifecycle is illustrated in Figure 10-1. Let’s take a look at what it takes to make each of these steps happen, from the first line of code to the last.

Figure 10-1. Request/response lifecycle

Bootstrapping the Application

Every Laravel application has some form of configuration set up at the web server level, in an Apache .htaccess file ...