Journey to the Center of Symfony: HttpKernel Request-Response

Let's not just use Symfony, let's conquer it! In this series, you and I will journey to the center of Symfony by ripping open the source code, adding debug statements and seeing what really happens between the request and the response. It's as geeky-awesome as it sounds.

Besides dinosaurs, expect to do the following on our adventure:

• Create an event listener that does amazing things
• Step through the HttpKernel::handle() method that's used in Symfony and Drupal 8
• See where event like kernel.request, kernel.response and others are dispatched
• Learn about request attributes and the magic they give us
• Find out what is a sub-request and how to handle it
• Create your own sub-request manually

• Interrupt Symfony with an Event Subscriber
• HttpKernel::handle() The Heart of Everything
• kernel.request and the RouterListener
• Finding and Instantiating the Controller
• kernel.controller Event & Controller Arguments
• The kernel.view Event
• Finishing with kernel.response and kernel.exception
• Symfony Magic: Replace the _controller
• Making an Argument Available to All Controllers
• What about Sub Requests?
• How Sub-Requests Work