Joshua Thijssen has a new post to his site looking "under the hood" at Symfony's autowiring functionality used to locate and initialize services for the framework as needed.

When asking people if they use Symfony’s autowiring functionality, an often heard excuse why people don’t use it is because of all the magic that is happening during autowiring. But just like most impressive magic tricks, once explained, it all boils down to a few simple principles and Symfony’s autowiring is nothing different in that perspective. In this blogpost I will explain the new autowiring and autoconfiguration features, and why you should love them.

He starts off with an example of how to define services manually. He then explains how these services are used in the code and how to pass in arguments when fetching. He then moves on to the automatic generation of the services (the autowiring) and how the framework is "tricked" into using the namespace of the discovered service as the name. This is also used in dependency handling. The post then covers when the autowiring won't work, autoconfiguration and how to set defaults on service definitions (for arguments).