enabling email only if within specific location - ios

Question

I have created an app which i only want to work if the user is within a specific area (i.e. i only want the user to be able to sent an email if they are within a specific state of the country)
can some please either-
a) point me in the direction of a tutorial on how to set up a GPS boundary, and how to check if a user is within said GPS boundary
or
b) write an example for creating a GPS area, and how to check if the user is within the area.
i have the latitude and longitude of the user stored to variables.
here is my location manager code:
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
NSLog(#"didUpdateToLocation: %#", newLocation);
CLLocation *currentLocation = newLocation;
if (currentLocation != nil) {
longditute = [NSString stringWithFormat:#"%.8f", currentLocation.coordinate.longitude];
Latitude = [NSString stringWithFormat:#"%.8f", currentLocation.coordinate.latitude];
}
// Stop Location Manager
[locationManager stopUpdatingLocation];
}
and my email code:
-(IBAction)actionEmailComposer{
if ([MFMailComposeViewController canSendMail]) {
if ([witnessResponse isEqual: #"Yes"]) {
MFMailComposeViewController *mailViewController = [[MFMailComposeViewController alloc]init];
mailViewController.mailComposeDelegate = self;
[mailViewController setSubject:[NSString stringWithFormat:#"Dob in a Hoon Report(Y)"]];
[mailViewController setMessageBody:[NSString stringWithFormat:#"Am I prepared to be called upon as a witness?: %# \n Rego Number: %# \n Vehicle Make: %# \n Vehicle Colour: %# \n Vehicle Type: %# \n Incident Date: %# \n Incident Time: %# \n Incident Location: %# \n Do I know the Driver?: %# \n Drivers Name (if Known) %# \n Driver Gender: %# \n Description of Incident: %# \n Name of Person Reporting Incident: %# \n Contact Number: %# \n" , witnessResponse, regoNumber.text, vehilceMake.text, vehilceColour.text, vehicleType.text, incidentDate.text, incidentTime.text, location.text, driverKnownResponse, driverName.text, driverGenderResponse, additionalInfo.text, usersName.text, usersPhoneNumber.text] isHTML:NO];
[self presentViewController:mailViewController animated:YES completion:nil];
NSData *imageData = UIImageJPEGRepresentation(image, 1.0);
[mailViewController addAttachmentData:imageData mimeType:#"image/jpg" fileName: [NSString stringWithFormat:#"Dob in a Hoon %# , %#.jpg", Latitude,longditute]];
[mailViewController setToRecipients:toRecipients];
} else {
MFMailComposeViewController *mailViewController = [[MFMailComposeViewController alloc]init];
mailViewController.mailComposeDelegate = self;
[mailViewController setSubject:[NSString stringWithFormat:#"Dob in a Hoon Report(N)"]];
[mailViewController setMessageBody:[NSString stringWithFormat:#"Am I prepared to be called upon as a witness?: %# \n Rego Number: %# \n Vehicle Make: %# \n Vehicle Colour: %# \n Vehicle Type: %# \n Incident Date: %# \n Incident Time: %# \n Incident Location: %# \n Do I know the Driver?: %# \n Drivers Name (if Known) %# \n Driver Gender: %# \n Description of Incident: %# \n Name of Person Reporting Incident: %# \n Contact Number: %# \n" , witnessResponse, regoNumber.text, vehilceMake.text, vehilceColour.text, vehicleType.text, incidentDate.text, incidentTime.text, location.text, driverKnownResponse, driverName.text, driverGenderResponse, additionalInfo.text, usersName.text, usersPhoneNumber.text] isHTML:NO];
[self presentViewController:mailViewController animated:YES completion:nil];
NSData *imageData = UIImageJPEGRepresentation(image, 1.0);
[mailViewController addAttachmentData:imageData mimeType:#"image/jpg" fileName: [NSString stringWithFormat:#"Dob in a Hoon %# , %#", Latitude,longditute]];
[mailViewController setToRecipients:toRecipients];
}
}
else{
NSLog(#"Device is unable to send email");
}
}
my goal is: if the person is outside the area, i want to display a UIAlert informing the user they are outside the area. If the person is inside the area, it will go through the email set up.

Answer 1

You want the CLLocationManager, and methods like startMonitoringForRegion:, which uses CLCircularRegion objects to define geographic regions.
If you look in the Xcode docs for startMonitoringForRegion, it has a link to a demo project called "Regions", which should get you started.