objective c - NSTimer? - Check Connection iOS -

i using following method check if app has connection. it's simple , works great needs.

+ (void)checkinternet:(connection)block {     nsurl *url = [nsurl urlwithstring:@"http://www.google.com/"];     nsmutableurlrequest *request = [nsmutableurlrequest requestwithurl:url];     request.httpmethod = @"head";     request.cachepolicy = nsurlrequestreloadignoringlocalandremotecachedata;     request.timeoutinterval = 10.0;      [nsurlconnection sendasynchronousrequest:request                                        queue:[nsoperationqueue mainqueue]                            completionhandler:      ^(nsurlresponse *response, nsdata *data, nserror *connectionerror)      {          block([(nshttpurlresponse *)response statuscode] == 200);      }]; } 

however, i'd if status doesn't return 200, i'd check again, @ least couple of times. what's best way 1 second intervals?

below how i'm calling above method.

 [self checkinternet:^(bool internet)     {          if (internet)          {              // "internet" aka google          }          else          {              // no "internet" aka no google          }     }]; 

i use reachability detecting general network connection issues (see end of answer). use following method executing retries.

- (void)performselector:(sel)aselector withobject:(id)anargument afterdelay:(nstimeinterval)delay; 

you adapt system following have new class method has optional number of retries.

nb. not tested following. give general idea.

// variable track number of retries left. if had shared instance // property easier. static nsuinteger maxconnectiontries = 0;  // new method lets pass retry count. + (void)checkinternet:(connection)block withmaxtries:(nsuinteger)maxtries {    maxconnectiontries=maxtries;    [self checkinternet:block]; }  // original code extended retry calling when code 200 // seen on delay of 1s. defaults old code when retry limit exceeded // or non 200 code received. + (void)checkinternet:(connection)block {     nsurl *url = [nsurl urlwithstring:@"http://www.google.com/"];     nsmutableurlrequest *request = [nsmutableurlrequest requestwithurl:url];     request.httpmethod = @"head";     request.cachepolicy = nsurlrequestreloadignoringlocalandremotecachedata;     request.timeoutinterval = 10.0;      [nsurlconnection sendasynchronousrequest:request                                        queue:[nsoperationqueue mainqueue]                            completionhandler:      ^(nsurlresponse *response, nsdata *data, nserror *connectionerror)      {          if ([(nshttpurlresponse *)response statuscode] != 200 &&              maxconnectionretries > 0){            maxconnectionretries--;            [self performselector:@selector(checkinternet:) withobject:block afterdelay:1.0];           }          else{            maxconnectionretries = 0;            block([(nshttpurlresponse *)response statuscode] == 200);          }      }]; } 

for general detection of internet connectivity, best use reachability. see here.

i start reachability handler appdelegate code , publish local notifications when connectivity changes occur. allows application receive connection change notification , transient view controllers within viewwillappear , viewwilldisappear register , deregister local notifications if interested in connection changes.