I'm using realm.io in a swift app. This is the first time I've had to run a migration since I have an app in production. I changed one of the models and added a couple of extra fields to it.
I followed the example in the documentation and then referenced the github repo's example when that didn't work. I assumed that it was probably more complex then what the example in the documentation was letting on.
Here's what I have in my appdelegate.swift file:
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
print ("i'm in here")
// Override point for customization after application launch.
// Inside your application(application:didFinishLaunchingWithOptions:)
window = UIWindow(frame: UIScreen.mainScreen().bounds)
window?.rootViewController = UIViewController()
window?.makeKeyAndVisible()
// copy over old data files for migration
let defaultPath = Realm.Configuration.defaultConfiguration.path!
let defaultParentPath = (defaultPath as NSString).stringByDeletingLastPathComponent
if let v0Path = bundlePath("default-v0.realm") {
do {
try NSFileManager.defaultManager().removeItemAtPath(defaultPath)
try NSFileManager.defaultManager().copyItemAtPath(v0Path, toPath: defaultPath)
} catch {}
}
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: 1,
// 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 < 1) {
// Nothing to do!
// Realm will automatically detect new properties and removed properties
// And will update the schema on disk automatically
}
})
// define a migration block
// you can define this inline, but we will reuse this to migrate realm files from multiple versions
// to the most current version of our data model
let migrationBlock: MigrationBlock = { migration, oldSchemaVersion in
if oldSchemaVersion < 1 {
}
print("Migration complete.")
}
Realm.Configuration.defaultConfiguration = Realm.Configuration(schemaVersion: 1, migrationBlock: migrationBlock)
// 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()
return true
}
The print never runs which I find strange. Am I screwing something up? I'm assuming I must be.
Here's what the documentation said to do, I'm not sure if they were leaving something off or not:
// Inside your application(application:didFinishLaunchingWithOptions:)
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: 1,
// 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 < 1) {
// Nothing to do!
// Realm will automatically detect new properties and removed properties
// And will update the schema on disk automatically
}
})
// 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
let realm = try! Realm()
Any ideas what I'm doing wrong?
This ended up being the solution. I cannot say that I came up with it on my own because I didn't. I got some excellent help from a wonderful engineer named Claire at realm.
Here's what needed to be done:
class RoomsViewController: UIViewController, UITableViewDelegate {
var activeRoom = -1
var room: Room? = nil
var array = [Room]()
lazy var realm:Realm = {
return try! Realm()
}()
var notificationToken: NotificationToken?
@IBOutlet weak var roomsTable: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
array = Array(realm.objects(Room.self))
setupUI()
// Set realm notification block
notificationToken = realm.addNotificationBlock { [unowned self] note, realm in
// TODO: you are going to need to update array
self.roomsTable.reloadData()
}
}
This is first view controller that get's loaded and it was immediately querying the realm database to build the array. With Claire's suggestion, Realm was lazy loaded (or tried) and the code to build the array was moved into the viewDidLoad method whereas before it was called at the top.
This allowed the realm to migration to run ahead. As you might imagine, I honestly assumed that the view never got loaded until after the application function loaded in the AppDelegate. However, I guess I was wrong.
So, this will solve it. If you ever happen to run into the same problem, give this a shot.
UPDATE:
Here's how the appDelegate function looks now:
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
// Inside your application(application:didFinishLaunchingWithOptions:)
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: 1,
// 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 < 1) {
migration.enumerate(Inventory.className()) { oldObject, newObject in
// No-op.
// dynamic properties are defaulting the new column to true
// but the migration block is still needed
}
migration.enumerate(Profile.className()) { oldObject, newObject in
// No-op.
// dynamic properties are defaulting the new column to true
// but the migration block is still needed
}
migration.enumerate(Room.className()) { oldObject, newObject in
// No-op.
// dynamic properties are defaulting the new column to true
// but the migration block is still needed
}
migration.enumerate(Box.className()) { oldObject, newObject in
// No-op.
// dynamic properties are defaulting the new column to true
// but the migration block is still needed
}
}
})
// 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
do {
_ = try Realm()
} catch let _ as NSError {
// print error
}
return true
}