CODEWITHSUNDEEP
iosxcodeswift2realm
Azat
Azat

Reputation: 6795

Issue with updating Realm objects

I have two Realm model classes

class ModelA: Object {
    let id = RealmOptional<Int>()
    dynamic var name: String!
    // some other variables that are also String! type
}

class ModelB: Object {
    let id = RealmOptional<Int>()
    let models = List<ModelA>()
    // other variables
}

And I have some JSON object which contains data for that models. I create ModelB instance then populate it with ModelA instances list the following way:

let json: JSON = ... // get it from somewhere, then use SwiftyJSON
let myModelB = ModelB()
myModelB.id.value = json["id"].object as? Int
// set other properties
let modelsA = json["models"].map { ModelA(value: $0.1.object) }
myModelB.models.appendContentsOf(modelsA)

The reason why I am using different approaches here is that propery names in JSON doesn't match to my property names for ModelB but for ModelA it is ok. Somewhere later I use realm.add(objects, update: true) (inside realm.write) and that leads to the following exception:

Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[ valueForUndefinedKey:]: this class is not key value coding-compliant for the key (null).'

According to the documentation:

If your model class includes a primary key, you can have Realm intelligently update or add objects based off of their primary key values using Realm().add(_:update:).

so both ModelA and ModelB has primaryKey() function and I believe that should work but it is not.

Furthermore, I removed update parameter in the call and added call to the realm.deleteAll() before adding new objects (both in write callback). In that case I get the following exception:

Terminating app due to uncaught exception 'RLMException', reason: 'Can't set primary key property 'id' to existing value 'xxxxxxx'.

Additionally if I try to go through the call stack, Xcode crashes. It also crashes if I try to inspect any Realm object in the debugger. I already have installed Realm Xcode plugin but nothing changes. I cannot understand what is going wrong here and why I get so strange behavior. Could someone tell me where is my mistake please?

Upvotes: 4

Views: 2548

Answers (1)

Gralex
Gralex

Reputation: 4485

I start project from scratch, base on example project. So I finished with:

import UIKit
import RealmSwift

// Dog model
class Dog: Object {
    dynamic var name = ""
    dynamic var age = 0
    dynamic var owner: Person? // Properties can be optional

    override class func primaryKey() -> String? { return "name" }
}

// Person model
class Person: Object {
    dynamic var name = ""
    let dogs = List<Dog>()

    override class func primaryKey() -> String? { return "name" }
}

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?


    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        // Override point for customization after application launch.

        do {
            try NSFileManager.defaultManager().removeItemAtPath(Realm.Configuration.defaultConfiguration.path!)
        } catch {}

        let dogRexJSON: AnyObject = ["name": "Rex", "age" : 20]
        let dogLuckyJSON: AnyObject = ["name": "Lucky", "age" : 25]
        var somePerson = Person(value: ["name" : "Shurik", "dogs" : [dogRexJSON]])


        // Realms are used to group data together
        let realm = try! Realm() // Create realm pointing to default file

        // Save your object
        realm.beginWrite()
        realm.add(somePerson)
        try! realm.commitWrite()

        somePerson = Person(value: ["name" : "Shurik", "dogs" : [dogRexJSON, dogLuckyJSON]])
        try! realm.write { () -> Void in
            realm.add([somePerson], update: true)
            return
        }

        let val = realm.objectForPrimaryKey(Dog.self, key: "Lucky")
        print(val!.name) // as expected log >> Lucky

        return true
    }
}

Seems all works fine.

Upvotes: 3

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