CODEWITHSUNDEEP
realmswift3
Mulgard
Mulgard

Reputation: 10589

Realm: Delete and Add Object: Object has been deleted or invalidated

I have multiple Objects which are not defining a primary key (because our server is handling the primary keys and in offline mode you cant provide a primary key) so i cant use the update method if i change data, so i tried the following:

func updateTest() {
    let myObjects = realm.objects(MyObject.self).filter("id = 1"); // id is NOT the primary key from realm!

    var myObject: MyObject!;

    if (myObjects.count > 0) {
        myObject = myObjects[0];
    }

    if (myObject != nil) {
        try! self.realm.write() {
            self.realm.delete(self.myObject);
        }

        // modify
        self.myObject.status = "waiting";

        try! self.realm.write() {
            self.realm.add(self.myObject); // crash
        }
    }
}

But when I want to add the object now i get:

Terminating app due to uncaught exception: 'RLMException', reason: 'Object has been deleted or invalidated.'

So several questions here:

Is there any possibility to select only a single result?

Is there any possibility to update an object by providing a field name which is not the primary key?

How can i delete and readd an object without getting this error?

would it maybe make sense to implement a dummy primary key?

Upvotes: 0

Views: 928

Answers (1)

bdash
bdash

Reputation: 18308

What you're trying to do can be accomplished like this:

func updateTest() {
    guard let myObject = realm.objects(MyObject.self).filter("id = 1").first else {
        return
     }

    try! realm.write {
        myObject.status = "waiting"
    }
}

Is there any possibility to select only a single result?

You can use Swift's guard let to bind the first element in the result set to a variable if one exists, using the else clause for your fallback if the object cannot be found. In this case I simply return from the function.

Is there any possibility to update an object by providing a field name which is not the primary key?

Yes. Perform a query to locate the object in question, then change its properties however you wish.

How can I delete and readd an object without getting this error?

You cannot delete and re-add an object. There's no way to resurrect a deleted object. It's not necessary to do this to get the behavior you're after.

Would it maybe make sense to implement a dummy primary key?

It's not necessary to get the behavior you're after.

Upvotes: 1

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