Best Practice And How To Implement Realmlist That Need To Support Different Types Of Objects

I have a model 'A' that have a list that can be of type 'B' or 'C' and more. I know Polymorphism is not supported by Realm and i cant just do RealmList or RealmL

Solution 1:

Polymorphism support is tracked here: https://github.com/realm/realm-java/issues/761 , but as long as it isn't implemented you have to use composition instead (https://en.wikipedia.org/wiki/Composition_over_inheritance)

In your case it would look something like this:

publicinterfaceMyContract {
  int calculate();
}

publicclassMySuperClassextendsRealmObjectimplementsMyContract {
  private A a;
  private B b;
  private C c;

  @Overridepublic int calculate() {
    returngetObj().calculate();
  }

  privateMyContractgetObj() {
    if (a != null) return a;
    if (b != null) return b;
    if (c != null) return c;
  }

  publicbooleanisA() { return a != null; }
  publicbooleanisB() { return b != null; }
  publicbooleanisC() { return c != null; }

  // ...
}