Swift default value of nil with optional flag not recognized, fails

[javierjulio]

If I have:

class FlashCard: RLMObject {
  dynamic var lastReviewedAt: NSDate? = nil
}

And then in a test case if I do the following:

  func test() {
    let realm = realmWithTestPath()

    let firstFlashCard = FlashCard()
    firstFlashCard.definition = "first"

    realm.transactionWithBlock() {
      realm.addObject(firstFlashCard)
    }
  }

I get the following error which is unexpected: failed: caught "RLMException", "No value or default value specified for property 'lastReviewedAt' in 'FlashCard'" since I set the value to nil and expect it at some points that it can be nil. Am I doing something wrong or is this default value not supported? Do I have to instantiate the FlashCard object within the block?

[javierjulio]

If I create the FlashCard instance within the transaction block nothing changes. I still receive the same error. Is it not possible to allow a default value of nil for a property? In this case not having a date set is important since it indicates that object hasn't been reviewed yet so I won't to allow for that case.

[jpsim]

Optional properties aren't really supported in Realm Swift. They are, but only if the property has a default value and the property is never set to nil. This is a duplicate of #628.

Relationships can be nil though. i.e. dynamic var ceo: Employee?

[GreatApe]

Optional properties are not supported yet, except for RLMObject properties. It is very high on the list, though. But what you can do is to wrap the date in an RLMObject subclass, and let that property be optional:

class DateObject: RLMObject {
  dynamic var date: NSDate = ...
}
class FlashCard: RLMObject {
  dynamic var lastReviewedAt: DateObject?
}

[javierjulio]

Thanks @jpsim and @GreatApe! This actually won't be much of a problem as I can work around it by using other properties on the object. Allowing nil would have simplified the queries but testing against other properties is just as clear so this isn't a huge deal. Also in fact its better, rather not have to worry about nils. Closing as a duplicate of #628.

[scottfister]

I am attempting to do this with a float or double and I get the error 'NSUnknownKeyException', reason: '[<__NSCFNumber 0x7fe509f350e0> valueForUndefinedKey:]: this class is not key value coding-compliant for the key float.'.

My code:

class NullableFloat: Object {
    dynamic var float: Float = 0.0
}
class Foo: Object {
  dynamic var bar : NullableFloat?
}

What am I doing wrong?

[jpsim]

@scottfister could you please open a new issue with step-by-step instructions to reproduce the issue you're seeing? Thanks!