iOS/iPhone Reachability - How to only check when internet is lost/not reachable using Reachability.m/.h

Question

Currently i am using the class by apple reachability.m/.h and it works, except it notifies me for any change, where as i would like to only notify the user if the network is not reachable. Currently if i have a internet connection and then loose the network it tells me. However when you reconnect to the network it also tells me, which i do not want. I want it to only tell me when there is a loss/no network.

I believe it has something to do with the call:

- (void)viewWillAppear:(BOOL)animated
{
    // check for internet connection
    [[NSNotificationCenter defaultCenter]
          addObserver:self
             selector:@selector(checkNetworkStatus:)
                 name:kReachabilityChangedNotification
               object:nil];

    internetReachable = [[Reachability
                         reachabilityForInternetConnection] retain];
    [internetReachable startNotifier];

    // check if a pathway to a random host exists
    hostReachable = [[Reachability reachabilityWithHostName:
                     @"www.google.ca"] retain];
    [hostReachable startNotifier];

    // now patiently wait for the notification
}

when calling -[NSNotificationCenter addObserver:selector:name:object:], does the name have any other function then being literally a name? this is my first time using NSNotificationCenter so i am not well versed in this matter.

EDIT:

Here is my checkNetworkStatus function: (The problem is i am getting "NotReachable" as the network connection is coming back and NSAlert goes off multiple times)

- (void) checkNetworkStatus:(NSNotification *)notice
{
        // called after network status changes
NetworkStatus internetStatus = [internetReachable currentReachabilityStatus];
switch (internetStatus)

{
    case NotReachable:
    {
        UIAlertView * alert  = [[UIAlertView alloc] initWithTitle:@"Network Failed" message:@"Please check your connection and try again." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil ];
        [alert show];
        NSLog(@"The internet is down.");

        break;

    }
    case ReachableViaWiFi:
    {               
        NSLog(@"The internet is working via WIFI.");

        break;

    }
    case ReachableViaWWAN:
    {
        NSLog(@"The internet is working via WWAN.");

        break;

    }
}

NetworkStatus hostStatus = [hostReachable currentReachabilityStatus];
switch (hostStatus)

{
    case NotReachable:
    {
        NSLog(@"A gateway to the host server is down.");

        break;

    }
    case ReachableViaWiFi:
    {
        NSLog(@"A gateway to the host server is working via WIFI.");

        break;

    }
    case ReachableViaWWAN:
    {
        NSLog(@"A gateway to the host server is working via WWAN.");

        break;

    }
}

}

Answer 1

Reachability will send a notification when the status has changed, but what you do with that notification is entirely up to you. If you don't want to tell the user that the network is back, you don't have to.

The "name" parameter in the NSNotificationCenter method indicates what notification you are subscribing to. When an object posts a notification, it does so with a particular name.