How to prevent a method from being called all the time - ios

Question

-(void) parseXML
{
[self performSelector:#selector(parseXML) withObject:self afterDelay:55.0 ];
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:#"http://apikeygoeshere.com/data.xml"]];
NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSString *xmlString = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];
NSDictionary *xml = [NSDictionary dictionaryWithXMLString:xmlString];
NSMutableArray *items = [xml objectForKey:#"TeamLeagueStanding"];
NSMutableArray *newTeamObjectArray = [[NSMutableArray alloc] init];
for (NSDictionary *dict in items) {
TeamObject *myTeams = [TeamObject teamFromXMLDictionary:dict];
[newTeamObjectArray addObject:myTeams];
}
NSNull *nullValue = [NSNull null];
NSNull *nullValue2 = [NSNull null];
[newTeamObjectArray insertObject:nullValue atIndex:0];
[newTeamObjectArray insertObject:nullValue2 atIndex:1];
NSLog(#"standingsdataaaaa %#", newTeamObjectArray);
}
I want to add a unbutton to my storyboard so the user can refresh the data whenever he wants, but i don't him to be able to do this more than once per hour,
Can anyone help me? Thank you.

Answer 1

Just in the action method or wherever you call to get the XML
setEnabled: NO and set an NSTimer to fire nod a date that is 3600 seconds from now.
When it fires, setEnabled:YES
It might be nice to create a visual indicator to the user like a counter.

Answer 2

EDIT: In order to account for the fact that you still want to run the parseXML method every 55 seconds with or without the button press, I'm changing my answer by putting the conditional in the IBAction method triggered by the button press instead of putting the conditional in parseXML:
Declare an NSTimer as a class variable. For example, at the top of your .m directly after your #synthesizes, declare an NSTimer:
NSTimer *parseTimer;
Then in the IBAction method triggered by the button press, only call parseXML if the timer is nil; and if it is in fact nil and the parseXML method is going to run, initiate the timer so it doesn't run again for another hour:
- (IBAction)buttonPressed:(sender)id {
// If the parseTimer is active, do call parseXML.
// (And perhaps fire an alert here)
if (parseTimer != nil) return;
// Otherwise initialize the timer so that it calls the the method which
// will deactivate it in 60*60 seconds, i.e. one hour
parseTimer = [NSTimer scheduledTimerWithTimeInterval:60*60 target:self selector:#selector(reactivateButton) userInfo:nil repeats:YES];
[self parseXML];
}
The deactivateParseTimer method should deactivate the timer and set it to nil so that parseXML may run again:
- (void)deactivateParseTimer {
[parseTimer invalidate];
parseTimer = nil;
}