Prevent Realm from overwriting a property when updating an Object

Question

I\'ve setup a REST API to realm object in iOS. However I\'ve found an issue with creating a favorite flag in my object. I\'ve created a favorite bool, however everytime the obje

Answer 1

There are two ways to solve this:

1. Use an Ignored Property:

You can tell Realm that a certain property should not be persisted. To prevent that your favorite property will be persisted by Realm you have to do this:

class Pet: Object{
    dynamic var id: Int = 1
    dynamic var title: String = ""
    dynamic var type: String = ""
    dynamic var favorite: Bool = false

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

    override static func ignoredProperties() -> [String] {
       return ["favorite"]
   }
}

or you could

2. Do a partial update

Or you could tell Realm explicitly which properties should be updated when you update your Pet object:

try! realm.write {
  realm.create(Pet.self, value: ["id": 2, "name": "Dog", "type": "German Shepard"], update: true)
}

This way the favorite property will not be changed.

Conclusion

There is one big difference between the two approaches:

Ignored Property: Realm won't store the favorite property at all. It is your responsibility to keep track of them.

Partial Update: Realm will store the 'favorite' property, but it won't be updated.

I suppose that the partial updates are what you need for your purpose.