在应用程序生命周期的中间将本地 Realm 转换为同步 Realm（在 Swift 中）

Question

My app will have a paid feature called multi-devices sync. I would like to implement the feature with Realm Cloud - Query Based Sync.

I know how to convert local Realm to synced Realm thanks to this thread .

But this is based on the scenario that users sync their Realm from the app start - before opening their non-synced local realm. That doesn't work for me because my users will start sync when they paid for it.

Therefore, I have to convert their local Realm in the middle of app life cycle and the local Realm is already opened by that time.

My issue comes in here. When I try to convert local realm to synced realm, app crashes with this message:

Realm at path '…' already opened with different read permissions.

I tried to find a way to close local Realm before converting it, but Realm cocoa does not allow me to close a Realm programmatically.

Here's my code converting local Realm to synced Realm.

func copyLocalRealmToSyncedRealm(user: RLMSyncUser) {

    let localConfig = RLMRealmConfiguration()
    localConfig.fileURL = Realm.Configuration.defaultConfiguration.fileURL
    localConfig.dynamic = true
    localConfig.readOnly = true

    // crashes here
    let localRealm = try! RLMRealm(configuration: localConfig)

    let syncConfig = RLMRealmConfiguration()
    syncConfig.syncConfiguration = RLMSyncConfiguration(user: user,
                                                        realmURL: realmURL,
                                                        isPartial: true,
                                                        urlPrefix: nil,
                                                        stopPolicy: .liveIndefinitely,
                                                        enableSSLValidation: true,
                                                        certificatePath: nil)
    syncConfig.customSchema = localRealm.schema

    let syncRealm = try! RLMRealm(configuration: syncConfig)
    syncRealm.schema = syncConfig.customSchema!
    try! syncRealm.transaction {
        let objectSchema = syncConfig.customSchema!.objectSchema
        for schema in objectSchema {
            let allObjects = localRealm.allObjects(schema.className)
            for i in 0..<allObjects.count {
                let object = allObjects[i]
                RLMCreateObjectInRealmWithValue(syncRealm, schema.className, object, true)
            }
        }
    }
}

Any help will be appreciated. Thanks.

Answer 1

I made a copy of the local realm file and opened the copy with RLMRealmConfiguration. Afterwards, just delete both files. It is not the best solution, but it works