RLMSyncError

An error that indicates a problem with the session (a specific Realm opened for sync).

An error that indicates a problem with a specific user.

An error that indicates an internal, unrecoverable problem with the underlying synchronization engine.

An error that indicates the Realm needs to be reset.

A synced Realm may need to be reset because MongoDB Realm encountered an error and had to be restored from a backup. If the backup copy of the remote Realm is of an earlier version than the local copy of the Realm, the server will ask the client to reset the Realm.

The reset process is as follows: the local copy of the Realm is copied into a recovery directory for safekeeping, and then deleted from the original location. The next time the Realm for that partition value is opened, the Realm will automatically be re-downloaded from MongoDB Realm, and can be used as normal.

Data written to the Realm after the local copy of the Realm diverged from the backup remote copy will be present in the local recovery copy of the Realm file. The re-downloaded Realm will initially contain only the data present at the time the Realm was backed up on the server.

The client reset process can be initiated in one of two ways.

The userInfo dictionary contains an opaque token object under the key kRLMSyncErrorActionTokenKey. This token can be passed into +[RLMSyncSession immediatelyHandleError:] in order to immediately perform the client reset process. This should only be done after your app closes and invalidates every instance of the offending Realm on all threads (note that autorelease pools may make this difficult to guarantee).

If +[RLMSyncSession immediatelyHandleError:] is not called, the client reset process will be automatically carried out the next time the app is launched and the RLMSyncManager is accessed.

The value for the kRLMSyncPathOfRealmBackupCopyKey key in the userInfo dictionary describes the path of the recovered copy of the Realm. This copy will not actually be created until the client reset process is initiated.

An error that indicates an authentication error occurred.

The kRLMSyncUnderlyingErrorKey key in the user info dictionary will contain the underlying error, which is guaranteed to be under the RLMSyncAuthErrorDomain error domain.

An error that indicates the user does not have permission to perform an operation upon a synced Realm. For example, a user may receive this error if they attempt to open a Realm they do not have at least read access to, or write to a Realm they only have read access to.

This error may also occur if a user incorrectly opens a Realm they have read-only permissions to without using the asyncOpen() APIs.

A Realm that suffers a permission denied error is, by default, flagged so that its local copy will be deleted the next time the application starts.

The userInfo dictionary contains an opaque token object under the key kRLMSyncErrorActionTokenKey. This token can be passed into +[RLMSyncSession immediatelyHandleError:] in order to immediately delete the local copy. This should only be done after your app closes and invalidates every instance of the offending Realm on all threads (note that autorelease pools may make this difficult to guarantee).