custom Annotations being switched when reloaded on MKMapView - objective-c

Question

I've been having this issue for a couple of weeks now, and I still have not found an answer. on my MapView I have custom annotations, and when I hit the "reload button" all the information is correct as in the annotation "title, subtitle". but the annotation has changed. the annotations are in a NSMutableArray and I'm sure that the issue i am having revolves around that. here is the code I am using to reload the annotations.
so just prevent any confusion, my custom annotations work just fine when i first load the mapView. But once i hit the reload button, all the annotation's information like "location,title, subtitle" all that is correct, just the actual annotation has changed. Like all the annotations have been switched around.
if anyone can help, it would greatly be appreciated! thanks!
- (IBAction)refreshMap:(id)sender {
NSArray *annotationsOnMap = myMapView.annotations;
[myMapView removeAnnotations:annotationsOnMap];
[locations removeAllObjects];
[citiesArray removeAllObjects];
[self retrieveData];
}
-(void) retrieveData {
userLAT = [NSString stringWithFormat:#"%f", myMapView.userLocation.coordinate.latitude];
userLNG = [NSString stringWithFormat:#"%f", myMapView.userLocation.coordinate.longitude];
NSString *fullPath = [mainUrl stringByAppendingFormat:#"map_json.php?userID=%#&lat=%#&lng=%#",theUserID,userLAT,userLNG];
NSURL * url =[NSURL URLWithString:fullPath];
NSData *data = [NSData dataWithContentsOfURL:url];
json =[NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
citiesArray =[[NSMutableArray alloc]init];
for (int i = 0; i < json.count; i++)
{
//create city object
NSString * eID =[[json objectAtIndex:i] objectForKey:#"userid"];
NSString * eAddress =[[json objectAtIndex:i] objectForKey:#"full_address"];
NSString * eHost =[[json objectAtIndex:i] objectForKey:#"username"];
NSString * eLat =[[json objectAtIndex:i] objectForKey:#"lat"];
NSString * eLong =[[json objectAtIndex:i] objectForKey:#"lng"];
NSString * eName =[[json objectAtIndex:i] objectForKey:#"Restaurant_name"];
NSString * eState = [[json objectAtIndex:i] objectForKey:#"type"];
NSString * annotationPic = [[json objectAtIndex:i] objectForKey:#"Annotation"];
NSString * eventID = [[json objectAtIndex:i] objectForKey:#"id"];
//convert lat and long from strings
float floatLat = [eLat floatValue];
float floatLONG = [eLong floatValue];
City * myCity =[[City alloc] initWithRestaurantID: (NSString *) eID andRestaurantName: (NSString *) eName andRestaurantState: (NSString *) eState andRestaurantAddress: (NSString *) eAddress andRestaurantHost: eHost andRestaurantLat: (NSString *) eLat andRestaurantLong: (NSString *) eLong];
//Add our city object to our cities array
// Do any additional setup after loading the view.
[citiesArray addObject:myCity];
//Annotation
locations =[[NSMutableArray alloc]init];
CLLocationCoordinate2D location;
Annotation * myAnn;
//event1 annotation
myAnn =[[Annotation alloc]init];
location.latitude = floatLat;
location.longitude = floatLONG;
myAnn.coordinate = location;
myAnn.title = eName;
myAnn.subtitle = eHost;
myAnn.type = eState;
myAnn.AnnotationPicture = annotationPic;
myAnn.passEventID = eventID;
myAnn.hotZoneLevel = hotZone;
[locations addObject:myAnn];
[self.myMapView addAnnotations:locations];
}
}
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
{
if([annotation isKindOfClass:[MKUserLocation class]])
return nil;
static NSString *annotationIdentifier = #"AnnotationIdentifier";
MKAnnotationView *annotationView = (MKAnnotationView *) [self.myMapView
dequeueReusableAnnotationViewWithIdentifier:annotationIdentifier];
if (!annotationView)
{
annotationView = [[MKAnnotationView alloc]
initWithAnnotation:annotation
reuseIdentifier:annotationIdentifier];
NSString *restaurant_Icon = ((Annotation *)annotation).AnnotationPicture;
NSString *restaurant_Callout = [NSString stringWithFormat:#"mini.%#",restaurant_Icon];
UIImage *oldImage = [UIImage imageNamed:restaurant_Icon];
UIImage *newImage;
CGSize newSize = CGSizeMake(75, 75);
newImage = [oldImage imageScaledToFitSize:newSize]; // uses MGImageResizeScale
annotationView.image= newImage;
annotationView.canShowCallout = YES;
UIImage *Mini_oldImage = [UIImage imageNamed:event_Callout];
UIImage *Mini_newImage;
CGSize Mini_newSize = CGSizeMake(30,30);
Mini_newImage = [Mini_oldImage imageScaledToFitSize:Mini_newSize]; // uses MGImageResizeScale
UIImageView *finalMini_callOut = [[UIImageView alloc] initWithImage:Mini_newImage];
annotationView.leftCalloutAccessoryView = finalMini_callOut;
UIButton* rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
annotationView.rightCalloutAccessoryView = rightButton;
}
else
{
annotationView.annotation = annotation;
}
return annotationView;
}

Answer 1

If nothing else, you're setting the icon and the callout based upon the annotation, but only doing that in viewForAnnotation if the annotation was not dequeued. You really want to do any annotation-specific customization outside of that if block, in case an annotation view is reused.
Unrelated to your reported issue, there are a few other observations:
You probably should be doing retrieveData asynchronously so you don't tie up the main thread with your data retrieval/parsing. Go ahead and dispatch the adding of the entry to your array and adding the annotation to the map in the main queue, but the network stuff and should definitely be done asynchronously.
You probably should check to make sure data is not nil (e.g. no network connection or some other network error) because JSONObjectWithData will crash if you pass it a nil value.
Your use of locations seems unnecessary because you're resetting it for every entry in your JSON. You could either (a) retire locations entirely and just add the myAnn object to your map's annotations; or (b) initialize locations before the for loop. But it's probably misleading to maintain this ivar, but only populate it with the last annotation.