Creating portable Bundles with extendable entities in Symfony2

Question

I want to create some Symfony2 bundles which are reusable accross different projects, but where the entities also can be easily extended if required.

An example could be a reusable UserBundle, which contains a User entity with all the ORM mappings defined. In my application however, I might want to extend this entity and add extra columns, associations or override some of the parent's mappings.

The closest solution I could find are Doctrine2's mapped superclasses, but then I'd lose the plug-and-playness of my reusable bundle, I'd always have to extend the mapped superclass in my application even if I don't wish to modify the mappings.

The other documented inheritance schemes require modifying the parent's mappings, and then my UserBundle wouldn't be portable anymore accross projects.

Is there a way to define a fully-working entity in one bundle, and still extend that in another bundle?

Answer 1

For future reference, this can be solved using target entity resolution.

You can find extra information in Symfony docs.

The steps are pretty straighforward:

1. Create an interface in your bundle for the User entity

   namespace Acme/UserBundle/Model;
   interface UserInterface
   {
       // public functions expected for entity User
   }
   

2. Make your base User entity implement the interface

   namespace Acme/UserBundle/Entity;
   /**
    * @ORM\Entity
    */
   class User implements UserInterface
   {
       // implement public functions
   }
   

3. Create relationships as usual, but using the interface

   namespace Acme/InvoiceBundle/Entity;
   /**
    * @ORM\Entity
    */
   class Invoice
   {
       /**
        * @ORM\ManyToOne(targetEntity="Acme\UserBundle\Model\UserInterface")
        */
       protected $user;
   }
   

4. Configure the listener by adding the following to config.yml

   doctrine:
       # ....
       orm:
           # ....
           resolve_target_entities:
               Acme\UserBundle\Model\UserInterface: Acme\UserBundle\Entity\User
   

If you want to customize User entity for your current application

1. Extend from the User class or implement UserInterface

   namespace Acme/WebBundle/Entity;
   use Acme/UserBundle/Entity/User as BaseUser;
   /**
    * @ORM\Entity
    */
   class User extends BaseUser
   {
       // Add new fields and functions
   }
   

2. Configure the listener accordingly

   doctrine:
       # ....
       orm:
           # ....
           resolve_target_entities:
               Acme\UserBundle\Model\UserInterface: Acme\WebBundle\Entity\User