CODEWITHSUNDEEP
objective-ciosxcode
bagwaa
bagwaa

Reputation: 359

Handling the Async event in CLGeocoder (iOS5)

I am trying to reverse geocode a location, I have managed todo this but I have hit a slight snag which is preventing me from completing it. I think I know WHAT it's doing and WHY, but I am not able to figure out a way to get around it yet. (I am using ARC and iOS5)

The problem occurs when I execute the following code in my init method ...

[self setSubtitle: [dateString stringByAppendingString: self.city ] ];

self.city is returning back a null value, I am pretty sure this is because the init method completes WAY before the geocoder can go and do it's thing.

So my question is, how can I handle this situation? I assume sitting and waiting for the geocoder to complete its work and freezing the app until such time isn't the way to go?

#import "MapPoint.h"

@implementation MapPoint
@synthesize coordinate, title, dateAdded, subtitle, city;

-(id)initWithCoordinates:(CLLocationCoordinate2D)c 
                   title:(NSString *)t {

    self = [super init];
    if (self) {

        coordinate = c;
        [self setTitle: t];
        [self setCurrentCity: [[CLLocation alloc] initWithLatitude:c.latitude longitude:c.longitude]];

        NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
        [formatter setTimeStyle:NSDateFormatterNoStyle];
        [formatter setDateStyle:NSDateFormatterLongStyle];

        [self setDateAdded: [[NSDate alloc] init]];
        NSString *dateString = [formatter stringFromDate: [self dateAdded]];

        [self setSubtitle: [dateString stringByAppendingString: self.city ] ];

    }
    return self;

}

-(void)setCurrentCity: (CLLocation *)loc {

    CLGeocoder *reverseGeo;

    if (!reverseGeo) {
        reverseGeo = [[CLGeocoder alloc] init];
    }

    [reverseGeo reverseGeocodeLocation: loc completionHandler: 
     ^(NSArray *placemarks, NSError *error) {
         if ([placemarks count] > 0) {

             CLPlacemark *topResult = [placemarks objectAtIndex:0];
             self.city = [NSString stringWithFormat:@"%@", [topResult locality]];

         }
     }];
}

@end

Upvotes: 2

Views: 3391

Answers (2)

bagwaa
bagwaa

Reputation: 359

turns out I needed to use a for loop to iterate through the results and set the annotation subtitle from here.

#import "MapPoint.h"

@implementation MapPoint
@synthesize coordinate, title, dateAdded, subtitle, city, reverseGeo;

-(id)initWithCoordinates:(CLLocationCoordinate2D)c 
                   title:(NSString *)t {

    self = [super init];
    if (self) {

        coordinate = c;
        [self setTitle: t];
        [self setCurrentCity: [[CLLocation alloc] initWithLatitude:c.latitude longitude:c.longitude]];

        [self setDateAdded: [[NSDate alloc] init]];

    }
    return self;

}

-(void)setCurrentCity: (CLLocation *)loc {

    if (!self.reverseGeo) {
        self.reverseGeo = [[CLGeocoder alloc] init];
    }

    [self.reverseGeo reverseGeocodeLocation: loc completionHandler: 
     ^(NSArray *placemarks, NSError *error) {

         for (CLPlacemark *placemark in placemarks) {

             NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
             [formatter setTimeStyle:NSDateFormatterNoStyle];
             [formatter setDateStyle:NSDateFormatterLongStyle];

             NSString *dateString = [formatter stringFromDate: [self dateAdded]];
             [self setSubtitle: [dateString stringByAppendingString: [placemark locality] ] ];             

         }
     }];
}

@end

Upvotes: 2

ennuikiller
ennuikiller

Reputation: 46965

you need to do something like this in the reverseGeocoder didFindPlacemark method:

- (void)reverseGeocoder:(MKReverseGeocoder *)geocoder didFindPlacemark:(MKPlacemark *)placemark {


    //progressLabel.text = NSLocalizedString(@"Location Determined", @"Location Determined");



    MapLocation *annotation = [[[MapLocation alloc] init] autorelease];
    annotation.streetNumber = placemark.subThoroughfare;
    annotation.streetAddress = placemark.thoroughfare;
    annotation.city = placemark.locality;
    }

Upvotes: -1

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