I am still trying to understand polymorphic associations in Doctrine2.
As I understand it, basic polymorphic associations work by using inheritance. If, for example, I had tables/classes OWNER, CAT and DOG, then the way to enable $owner->pet to point at either the CAT or the DOG table, would be to have them each extend a fourth class, PET, which is known as a mapped superclass. Then $owner->pet could return either a CAT or a DOG depending on what had been assigned, and Doctrine2 would be able to distinguish them.
That's simple enough. But what if I want to have two polymorphic associations which can point at the same object? For example, lets say that I have a table of ADMIRALS, each of which could command a FLEET or a PLANET. Let's also say that I have a table of SECTORS, each of which could contain a PLANET or a MOON.
Let's assume that I want $admiral->command to reference both PLANETS and FLEETS, and that I want $sector->contents to reference both PLANETS and MOONS. PLANET can't extend both command and contents as mapped superclasses. Is there a different way to make this work?
you can try ResolveTargetEntityListener see
you can point admiral's command property to an Interface, which is implemented by both PLANETS and FLEETS
the same is with sector's contents