symfony/symfony-docs — pull request #993 by richsage (2012-01-15 20:42:44+00:00)
Title: Clarified the use of the validatedBy method for custom contraint validators

I've added a bit of blurb to clarify the need to override the `validatedBy` method when using a custom constraint validator that is defined as a service. Without returning the alias used when defining the service, the class is just instantiated as normal without any dependencies. The use of the word "may" in the existing documentation implies that it's not strictly necessary to override, but it is when other dependencies need injecting in.