NSManagedObject won't be updated after saving with Magical Record

Question

I have a NSManagedObject (File) with some properties and I wrote some code that downloads a file with AFNetworking based on the information in this NSManagedObject - the download works fine! Now I want to change some MetaData in the completion block and save the changes to CoreData using Magical Record. This basically works, except I have to restart the App to get the new values of the NSManagedObject - And this is the problem. During one lifecycle I'm not able to get the updated NSManagedObject. I even tried to refetch the object...

I don't understand, why I would have to restart to App to get the updated information? Is there a context issue? I don't see it.

I get the File Object from the defaultContext:

NSManagedObjectContext *managedObjectContext = [NSManagedObjectContext MR_defaultContext];
NSFetchRequest *fetch = [[NSFetchRequest alloc] init];
[fetch setEntity:[NSEntityDescription entityForName:@"File" inManagedObjectContext:managedObjectContext]];

And here's my download method:

- (void)downloadFile:(File*)fileObject {

...

    completionBlock:^(AFHTTPRequestOperation *operation, id responseObject) {
        [MagicalRecord saveWithBlockAndWait:^(NSManagedObjectContext *localContext) {
            File *localFile = [fileObject MR_inContext:localContext];
            localFile.downloadStatus_ = [NSNumber numberWithInt:DownloadStatusCompleted];
         }];

        NSLog(@"State: %@"fileObject.downloadStatus_);

    }

}

Update: I changed the line and it worked. I'm puzzled. I would guess, that localContext should actually be the current context. Which should be the one the object's.

File *localFile = [fileObject MR_inContext:localContext];

to

File *localFile = [fileObject MR_inContext:[NSManagedObjectContext MR_defaultContext]];

Answer 1

I figured out what happened and wanted to post the answer.

It turned out that a property of the NSManagedObject *fileObject was changed without saving it, in advance of calling the completionBlock! The StoreCoordinator tries to merge and save the changed property (within the completionBlock) - but this operation failed since the original object from the context was changed...