Add `Realm.delete(RealmList)` and `Realm.delete(RealmResults) to remove RealmObjects

Cocoa binding has the similar functions See https://realm.io/docs/swift/latest/api/Classes/Realm.html#/s:FC10RealmSwift5Realm6deleteuRq_Ss12SequenceTypedqqq_S1_9GeneratorSs13GeneratorType7ElementCS_6Object_FS0_Fq_T_

Currently, All objects in RealmResults can be deleted by RealmResults.clear() But there is no function to delete all objects from RealmList

[cmelchior]

We probably need to consider our whole API in this area, as right now it isn’t as clear as one could hope IMO. I think the original idea was to stick as close to the Java Collection API methods as possible, which makes a lot of sense. However, how they work differ based on the type, which makes the API harder to understand:

realm.clear(clazz); // Deletes all objects of a given type from the Realm

realmResults.clear(); // Deletes all query results from the Realm
realmResults.remove(int location); // Removes item from Realm, returns null
realmResults.removeLast(); Removes last item from Realm
// Why no removeFirst?

realmList.clear(); // Removes items from the List, but not Realm
realmList.remove(int location); // Removes items from the List, but not Realm. Returns item
// Why no removeLast/First?

realmObject.removeFromRealm(); // Removes the object from Realm. isValid() now returns false.

Maybe it would make more sense to use the RealmList semantics everywhere? That would be more inline with Java semantics, would allow people to manipulate the results outside a write transaction, and would allow people to up-cast RealmResults to List without problems.

Given that you need a write-transaction anyway to actually delete the Realm data. Adding special methods for removing would probably be cleaner?

realm.removeFromRealm(obj)
realm.removeFromRealm(collection);

realmResults.removeLastFromRealm()
realmResults.removeFromRealm(int location)
realmResults.removeAllFromRealm();

realmList.removeFromRealm(int location)
realmList.removeAllFromRealm();

Objective C uses delete* instead of remove*. Something worth considering if we moved away from the collection API methods anyway.

What do you think?

[nicks258]

it says cannot resolve method ‘deleteAll()’ when i am using Realm.deleteAll()