Tomas Votruba: How to Slowly Turn your Symfony Project to Legacy with Action Injection

Tomas Votruba has a new post to his site showing how to "turn your Symfony project to legacy" through the use of action injection for mapping controllers and methods to request handling.

The other day I saw the question on Reddit about Symfony's controller action dependency injection. More people around me are hyped about this new feature in Symfony 3.3 that allows to autowire services via action argument typehints. It's new, it's cool and no one has a bad experience with it. The ideal candidate for any code you write today.

Since Nette and Laravel introduced a similar feature in 2014, there are empirical data that we learn from.

Today I'll share the experience I have from consulting few Nette applications with dangerous overuse of this pattern and how this one thing turned the code to complete mess.

He starts off with some example code, asking where the issue is showing a call to a service handler to process the an argument. This would be used when a controller is registered as a service to help reduce the amount of work to define routes and add more "magic" for request handling. While the idea sounds good, he points out some of the issues with the approach including dependency injection problems and how, if it expands outside of controllers, it can lead to a poorly written application.