Warning: You are browsing the documentation for version 4.1 which is not maintained anymore.
If some of your projects are still using this version, consider upgrading.
Doctrine2 is very flexible, and the community has already created a series of useful Doctrine extensions to help you with common entity-related tasks.
The usage for each of these extensions is explained in that repository.
However, to install/activate each extension you must register and activate an Event Listener. To do this, you have two options: