native code example

FirebaseRemoteConfig

    FIRRemoteConfig *remoteConfig = [FIRRemoteConfig remoteConfig];
    long expiration = (long)call.arguments[@"expiration"];

    [remoteConfig
        fetchWithExpirationDuration:expiration
                  completionHandler:^(FIRRemoteConfigFetchStatus status, NSError *error) {
                    NSNumber *lastFetchTime = [[NSNumber alloc]
                        initWithLong:(long)[[remoteConfig lastFetchTime] timeIntervalSince1970] *
                                     1000];
                    NSString *lastFetchStatus =
                        [self mapLastFetchStatus:(FIRRemoteConfigFetchStatus)[remoteConfig
                                                                                  lastFetchStatus]];
                    NSMutableDictionary *resultDict = [[NSMutableDictionary alloc] init];
                    resultDict[@"lastFetchTime"] = lastFetchTime;
                    resultDict[@"lastFetchStatus"] = lastFetchStatus;

                    if (status != FIRRemoteConfigFetchStatusSuccess) {
                      FlutterError *flutterError;
                      if (status == FIRRemoteConfigFetchStatusThrottled) {
                        int mills =
                            [[error.userInfo
                                valueForKey:FIRRemoteConfigThrottledEndTimeInSecondsKey] intValue] *
                            1000;
                        resultDict[@"fetchThrottledEnd"] = [[NSNumber alloc] initWithInt:mills];
                        NSString *errorMessage =
                            @"Fetch has been throttled. See the error's fetchThrottledEnd "
                             "field for throttle end time.";
                        flutterError = [FlutterError errorWithCode:@"fetchFailedThrottled"
                                                           message:errorMessage
                                                           details:resultDict];
                      } else {
                        NSString *errorMessage = @"Unable to complete fetch. Reason is unknown "
                                                  "but this could be due to lack of connectivity.";
                        flutterError = [FlutterError errorWithCode:@"fetchFailed"
                                                           message:errorMessage
                                                           details:resultDict];
                      }
                      result(flutterError);
                    } else {
                      result(resultDict);
                    }
                  }];