Reachability

NPReachability+Backward.h

//
//  NPReachability+Backward.h
//  
//  NPReachability+Backward is a category over the NPReachability class.
//  
//  It implements some of the Reachability methods and thus makes it easy to integrate with existing projects.
//

#import <Foundation/Foundation.h>
#import "NPReachability.h"

typedef enum {
	NotReachable = 0,
	ReachableViaWiFi,
	ReachableViaWWAN
} NetworkStatus;
#define kReachabilityChangedNotification @"kNetworkReachabilityChangedNotification"

/**
	A backward compatibility category over NPReachability.
	An implementation of some of the classic Reachability class.
*/
@interface NPReachability (Backward)

//reachabilityForInternetConnection- checks whether the default route is available.  
//  Should be used by applications that do not connect to a particular host
+ (NPReachability*) reachabilityForInternetConnection;

//reachabilityForLocalWiFi- checks whether a local wifi connection is available.
+ (NPReachability*) reachabilityForLocalWiFi;

//Start listening for reachability notifications on the current run loop
- (BOOL) startNotifer;
- (void) stopNotifer;

- (APNetworkStatus) currentReachabilityStatus;

@end

NPReachability+Backward.m

//
//  NPReachability+Backward.m
//  
//
//  Created by Tom Susel on 5/10/11.
//

#import "NPReachability+Backward.h"

@interface NPReachability ()

- (NetworkStatus) networkStatusForFlags: (SCNetworkReachabilityFlags) flags;

@end

void (^reachabilityDidChange)(SCNetworkReachabilityFlags flags) = ^(SCNetworkReachabilityFlags flags){
    [[NSNotificationCenter defaultCenter] postNotificationName:kReachabilityChangedNotification
                                                        object:[NPReachability sharedInstance]];
};

@implementation NPReachability (Backward)

//reachabilityWithHostName- Use to check the reachability of a particular host name. 
+ (NPReachability*) reachabilityWithHostName: (NSString*) hostName{
    return [NPReachability sharedInstance];
}

//reachabilityWithAddress- Use to check the reachability of a particular IP address. 
+ (NPReachability*) reachabilityWithAddress: (const struct sockaddr_in*) hostAddress{
    return [NPReachability sharedInstance];
}

//reachabilityForInternetConnection- checks whether the default route is available.  
//  Should be used by applications that do not connect to a particular host
+ (NPReachability*) reachabilityForInternetConnection{
    return [NPReachability sharedInstance];
}

//reachabilityForLocalWiFi- checks whether a local wifi connection is available.
+ (NPReachability*) reachabilityForLocalWiFi{
    return [NPReachability sharedInstance];
}

- (BOOL) startNotifer{
    [[NPReachability sharedInstance] addHandler:reachabilityDidChange];
    return YES;
}

- (void) stopNotifer{
    [[NPReachability sharedInstance] removeHandler:reachabilityDidChange];
}


- (NetworkStatus) currentReachabilityStatus{
    return [self networkStatusForFlags:
            [self currentReachabilityFlags]];
}

#pragma mark - 
#pragma mark NPReachability+Backward - Private

- (NetworkStatus) networkStatusForFlags: (SCNetworkReachabilityFlags) flags
{
	if ((flags & kSCNetworkReachabilityFlagsReachable) == 0)
	{
		// if target host is not reachable
		return NotReachable;
	}
    
	BOOL retVal = NotReachable;

	if ((flags & kSCNetworkReachabilityFlagsConnectionRequired) == 0)
	{
		// if target host is reachable and no connection is required
		//  then we'll assume (for now) that your on Wi-Fi
		retVal = ReachableViaWiFi;
	}


	if ((((flags & kSCNetworkReachabilityFlagsConnectionOnDemand ) != 0) ||
         (flags & kSCNetworkReachabilityFlagsConnectionOnTraffic) != 0))
	{
        // ... and the connection is on-demand (or on-traffic) if the
        //     calling application is using the CFSocketStream or higher APIs
        
        if ((flags & kSCNetworkReachabilityFlagsInterventionRequired) == 0)
        {
            // ... and no [user] intervention is needed
            retVal = ReachableViaWiFi;
        }
    }

	if ((flags & kSCNetworkReachabilityFlagsIsWWAN) == kSCNetworkReachabilityFlagsIsWWAN)
	{
		// ... but WWAN connections are OK if the calling application
		//     is using the CFNetwork (CFSocketStream?) APIs.
		retVal = ReachableViaWWAN;
	}
	return retVal;
}

@end