How do I know if cellular access for my iOS app is disabled?

Question

I have an iOS app that makes some small network requests on app launch (resource updates, etc). If the user turns off cellular access for the app in iOS Settings, they get

Answer 1

Just wanted to add an Objective C version of the above Swift code for future travellers.

- (void)monitorCanUseCellularData {
    if (GCIsiOS9) {
        CTCellularData *cellularData = [[CTCellularData alloc] init];
        NSLog(@"%ld", cellularData.restrictedState);
        // 0, kCTCellularDataRestrictedStateUnknown
        [cellularData setCellularDataRestrictionDidUpdateNotifier:^(CTCellularDataRestrictedState state) {
            NSLog(@"%ld", state);
            self.canUseCellularData = cellularData.restrictedState ==2?true:false;
        }];
    }
}