Getting invalid property name when trying to perform Realm migration - swift

Question

I'm having trouble with Realm giving me the error that a property of a given name does not exist for my object. But I know it does exist.
I've tried to follow the docs at https://realm.io/docs/swift/latest/#updating-values. I've searched for everything I can think of to find an applicable solution here and elsewhere, but nothing I've found works.
I previously performed a simple migration to just add properties to a different object within the same Realm. I just left the migration block empty and that worked fine. That migration should have set my schema from 0 to 1. If I run this with my schema set to 1 and to check for versions less than 2, it tells me that migration must be run in order to add these properties. The migration is running. I have a print statement for every time it executes. If I set the schema to 2, still checking for less than 2, I get the error for invalid property name for the old properties unless I uncomment them. Then I still get the error for the new properties.
Here's my Realm object. The commented out lines are the old properties I want to migrate from. The Int values are what I'm migrating to.
#objcMembers class Options: Object {
// dynamic var morningStartTime: Date?
// dynamic var afternoonStartTime: Date?
// dynamic var eveningStartTime: Date?
// dynamic var nightStartTime: Date?
dynamic var morningHour: Int = 7
dynamic var morningMinute: Int = 0
dynamic var afternoonHour: Int = 12
dynamic var afternoonMinute: Int = 0
dynamic var eveningHour: Int = 17
dynamic var eveningMinute: Int = 0
dynamic var nightHour: Int = 21
dynamic var nightMinute: Int = 0
dynamic var morningNotificationsOn: Bool = true
dynamic var afternoonNotificationsOn: Bool = true
dynamic var eveningNotificationsOn: Bool = true
dynamic var nightNotificationsOn: Bool = true
dynamic var firstItemAdded: Bool = false
dynamic var smartSnooze: Bool = false
dynamic var optionsKey = UUID().uuidString
override static func primaryKey() -> String? {
return "optionsKey"
}
}
My migration block:
let config = Realm.Configuration(
// Set the new schema version. This must be greater than the previously used
// version (if you've never set a schema version before, the version is 0).
schemaVersion: 2,
// Set the block which will be called automatically when opening a Realm with
// a schema version lower than the one set above
migrationBlock: { migration, oldSchemaVersion in
// We haven’t migrated anything yet, so oldSchemaVersion == 0
if (oldSchemaVersion < 2) {
migration.enumerateObjects(ofType: Options.className(), { (newObject, oldObject) in
let morningStartTime = oldObject!["morningStartTime"] as! Date?
let afternoonStartTime = oldObject!["afternoonStartTime"] as! Date?
let eveningStartTime = oldObject!["eveningStartTime"] as! Date?
let nightStartTime = oldObject!["nightStartTime"] as! Date?
newObject!["morningHour"] = self.getHour(date: morningStartTime)
newObject!["morningMinute"] = self.getMinute(date: morningStartTime)
newObject!["afternoonHour"] = self.getHour(date: afternoonStartTime)
newObject!["afternoonMinute"] = self.getMinute(date: afternoonStartTime)
newObject!["eveningHour"] = self.getHour(date: eveningStartTime)
newObject!["eveningMinute"] = self.getMinute(date: eveningStartTime)
newObject!["nightHour"] = self.getHour(date: nightStartTime)
newObject!["nightMinute"] = self.getMinute(date: nightStartTime)
})
}
})
getHour and getMinute are just functions I wrote to return an Int for the hour or minute from a Date. In case it's relevant, here they are.
func getHour(date: Date?) -> Int {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "HH"
let hour = dateFormatter.string(from: date!)
return Int(hour)!
}
func getMinute(date: Date?) -> Int {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "mm"
let minutes = dateFormatter.string(from: date!)
return Int(minutes)!
}

Answer 1

I know this is not the way to do it, but I made it work by taking a slightly more manual approach to the migration block. I uncommented the old properties in the Options object and changed my migration function to the following:
func migrateRealm() {
let configCheck = Realm.Configuration();
do {
let fileUrlIs = try schemaVersionAtURL(configCheck.fileURL!)
print("schema version \(fileUrlIs)")
} catch {
print(error)
}
print("performing realm migration")
let config = Realm.Configuration(
// Set the new schema version. This must be greater than the previously used
// version (if you've never set a schema version before, the version is 0).
schemaVersion: 2,
// Set the block which will be called automatically when opening a Realm with
// a schema version lower than the one set above
migrationBlock: { migration, oldSchemaVersion in
print("oldSchemaVersion: \(oldSchemaVersion)")
if (oldSchemaVersion < 2) {
print("Migration block running")
DispatchQueue(label: self.realmDispatchQueueLabel).async {
autoreleasepool {
let realm = try! Realm()
let options = realm.object(ofType: Options.self, forPrimaryKey: self.optionsKey)
do {
try realm.write {
if let morningTime = options?.morningStartTime {
options?.morningHour = self.getHour(date: morningTime)
options?.morningMinute = self.getMinute(date: morningTime)
}
if let afternoonTime = options?.afternoonStartTime {
options?.afternoonHour = self.getHour(date: afternoonTime)
options?.afternoonMinute = self.getMinute(date: afternoonTime)
}
if let eveningTime = options?.eveningStartTime {
options?.eveningHour = self.getHour(date: eveningTime)
options?.eveningMinute = self.getMinute(date: eveningTime)
}
if let nightTime = options?.nightStartTime {
options?.nightHour = self.getHour(date: nightTime)
options?.nightMinute = self.getMinute(date: nightTime)
}
}
} catch {
print("Error with migration")
}
}
}
}
})
// Tell Realm to use this new configuration object for the default Realm
Realm.Configuration.defaultConfiguration = config
// Now that we've told Realm how to handle the schema change, opening the file
// will automatically perform the migration
_ = try! Realm()
}
This only worked if I queued it on another thread asynchronously. I imagine if this data had been necessary for my initial view controller, then it probably would have created a race condition that caused the app to crash. Luckily this only appears in a secondary view, so it had time to complete before these values are needed. I guess I'll have to remove the unused properties with an updated Realm schema in a future version of my app.