User relations being cleared after loading more relations - iOS

iOS
1

None of my relations are on autoload, for efficiency’s sake. I am loading relations in rounds, getting some in the first round (in the viewDidLoad) and moving on to round 2 of loading relations after the view has loaded. My code to retrieve the first set of relations is as follows:

Fault *fault = nil;
BackendlessDataQuery *query = [BackendlessDataQuery new];
query.whereClause = [NSString stringWithFormat:@"objectid = \'%@\'", userToDisplay.objectId];
query.queryOptions.related = [NSMutableArray arrayWithArray:@[@"relation1", @"relation2", @"relation3.relation1-of-relation3"]];
NSArray *userData = [[backendless.persistenceService of:BackendlessUser.class] find:query fault:&fault].data;
userToDisplay = [userData objectAtIndex:0];

This is working fine, and userToDisplay now references a BackendlessUser object with the specified relations.
The second round of loading is as follows:

[backendless.persistenceService
load:userToDisplay

 relations:@[@"relation3.relation2-of-relation3", @"relation3.relation3-of-relation3", @"relation4.*"]
 response:^(id response)
 {
 userEvents = [self getUserEventsWithUser: userToDisplay];
 }
 error:^(Fault *fault)
 {
 NSLog(@"Fault: %@", fault.description);
 }];

This is where the problem starts. Now, userToDisplay is a reference to a BackendlessUser object with relation1, relation2, and relation3, but only the sub-relations relation3.relation2-of-relation3 and relation3.relation3-of-relation3.
relation3.relation1-of-relation3, which I retrieved in the first round of loading, is now empty. This is a problem because I do not want to have to load it again because I already did, but if I don’t, it is empty.
Is there any way to add on more sub-relations to a user without emptying the sub-relations that aren’t specified in the second load?
Thanks

2

You can merge the existing properties with loaded properties of user, for example:

-(void)mergingUser:(BackendlessUser *)user withRelations:(NSArray<NSString*> *)relations {
 
 [backendless.persistenceService
 load:user
 relations:relations
 response:^(id response) {
 BackendlessUser *loadedUser = (BackendlessUser *)response;
 NSDictionary<NSString*, id> *properties = [user retrieveProperties];
 // merge the user properties
 [loadedUser addProperties:properties];
 NSLog(@"%@", loadedUser);
 }
 error:^(Fault *fault) {
 NSLog(@"%@", fault);
 }];
}
3

Thank you, works like a charm.