Initial sync and duplicate objects with same primary key inside Realm Mobile Platform - realm

Question

I'm trying to turn on realm sync on device which already contains some data, that already persists on server. When new user connects to realm, it should merge local realm data with synced realm data. But this code is launched before initial sync happens. Since there is no data from server is received yet, app creates some records in synchronized realm. When sync finishes I see same data twice. Records I've just created and data fetched from server. With same primary key.
See code below for an example:
RLMRealmConfiguration *config = [[RLMRealmConfiguration alloc] init];
config.syncConfiguration = [[RLMSyncConfiguration alloc] initWithUser:user realmURL:self.realmURL];
NSError *error = nil;
RLMRealm *newRealm = [RLMRealm realmWithConfiguration:config error:&error];
if(newRealm != nil && error == nil)
{
[newRealm beginWriteTransaction];
for(ModelFolder *folder in [ModelFolder allObjectsInRealm:curRealm])
{
ModelFolder *newFolder = [ModelFolder objectInRealm:newRealm forPrimaryKey:folder.uuid];
if(newFolder == nil)
[ModelFolder createInRealm:newRealm withValue:folder];
}
[newRealm commitWriteTransaction];
}
Is there a way to detect, that realm is completed initial sync?
UPD: Few more details.
ModelFolder contains #property RLMArray<ModelBookmark *><ModelBookmark> *bookmarks; And when I create Folder, that equals some folder that will be fetched in a few seconds they merged correctly. But. Bookmarks inside Folder object is not deduplicated and we get something like this:
RLMResults <0x802082d0> (
[0] ModelFolder {
uuid = 2615AB34-1C08-4E7B-8D49-6E02EDBCDF89;
name = (null);
descr = (null);
shareURL = (null);
date = 1484566331137;
bookmarks = RLMArray <0x806c78d0> (
[0] ModelBookmark {
uuid = C752FCEB-65CB-47C8-8CF4-6CA44C119ECC;
name = (null);
descr = (null);
shareURL = (null);
date = 1484566331137;
folderUuid = 2615AB34-1C08-4E7B-8D49-6E02EDBCDF89;
longitude = 27.54834598813616;
latitude = 53.91333128839566;
mapZoom = 11.73785983313041;
category = 0;
visible = 1;
},
[1] ModelBookmark {
uuid = C752FCEB-65CB-47C8-8CF4-6CA44C119ECC;
name = (null);
descr = (null);
shareURL = (null);
date = 1484566331137;
folderUuid = 2615AB34-1C08-4E7B-8D49-6E02EDBCDF89;
longitude = 27.54834598813616;
latitude = 53.91333128839566;
mapZoom = 11.73785983313041;
category = 0;
visible = 1;
}
);
tracks = RLMArray <0x806fb120> (
);
opened = 1;
}
)

Answer 1

Unfortunately merging of the ordered lists is not supported currently (until https://github.com/realm/realm-core/issues/1206 is implemented). For now you have to manually deduplicate list items, you can use the same workaround we use in RealmTasks app, see https://github.com/realm/RealmTasks/pull/180 for implementation details.