first run check

AppDelegate

-(void)checkIfFirstRun{
    NSString *bundleVersion = [[NSBundle mainBundle] objectForInfoDictionaryKey:(NSString *)kCFBundleVersionKey];
    NSString *appFirstStartOfVersionKey = [NSString stringWithFormat:@"first_start_%@", bundleVersion];
    NSNumber *alreadyStartedOnVersion = [[NSUserDefaults standardUserDefaults] objectForKey:appFirstStartOfVersionKey];
    
    if(!alreadyStartedOnVersion || [alreadyStartedOnVersion boolValue] == NO) {
        // Preload plist data
        [self parsePlistIntoCD];
        [[NSUserDefaults standardUserDefaults] setObject:[NSNumber numberWithBool:YES] forKey:appFirstStartOfVersionKey];
    }
}

-(void)parsePlistIntoCD{
    NSString *fullFileName = @"PreloadedFarsiman.plist";
    NSString *plistPath;
    // 1: Get the Path to the plist file
    NSString *rootPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES) objectAtIndex:0];
    plistPath = [rootPath stringByAppendingPathComponent:fullFileName];
    if (![[NSFileManager defaultManager] fileExistsAtPath:plistPath]) {
        plistPath = [[NSBundle mainBundle] pathForResource:@"PreloadedFarsiman" ofType:@"plist"];
    }
    // 2: Read in the plist file
    NSDictionary *plistDictionary = [NSDictionary dictionaryWithContentsOfFile:plistPath];
    
    //Now put the plistDictionary into CD...
}

ParseClass

- (NSURL *)applicationCacheDirectory{
    return [[[NSFileManager defaultManager] URLsForDirectory:NSCachesDirectory inDomains:NSUserDomainMask] lastObject];
}

- (NSURL *)JSONDataRecordsDirectory{
    
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSURL *url = [NSURL URLWithString:@"JSONRecords/" relativeToURL:[self applicationCacheDirectory]];
    NSError *error = nil;
    if (![fileManager fileExistsAtPath:[url path]]) {
        [fileManager createDirectoryAtPath:[url path] withIntermediateDirectories:YES attributes:nil error:&error];
    }
    
    return url;
}

- (void)writeJSONResponse:(id)response toDiskForClassWithName:(NSString *)className {
    NSURL *fileURL = [NSURL URLWithString:className relativeToURL:[self JSONDataRecordsDirectory]];
    if (![(NSDictionary *)response writeToFile:[fileURL path] atomically:YES]) {
        NSLog(@"Error saving response to disk, will attempt to remove NSNull values and try again.");
        // remove NSNulls and try again...
        NSArray *records = [response objectForKey:@"results"];
        NSMutableArray *nullFreeRecords = [NSMutableArray array];
        for (NSDictionary *record in records) {
            NSMutableDictionary *nullFreeRecord = [NSMutableDictionary dictionaryWithDictionary:record];
            [record enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
                if ([obj isKindOfClass:[NSNull class]]) {
                    [nullFreeRecord setValue:nil forKey:key];
                }
            }];
            [nullFreeRecords addObject:nullFreeRecord];
        }
        
        NSDictionary *nullFreeDictionary = [NSDictionary dictionaryWithObject:nullFreeRecords forKey:@"results"];
        
        if (![nullFreeDictionary writeToFile:[fileURL path] atomically:YES]) {
            NSLog(@"Failed all attempts to save reponse to disk: %@", response);
        }
    }
}