CoreLocation object, can't assign longitude

Question

I'm building an app that works with MapKit and I need to get coordinates from Google Maps.

I made a function that does this (and through debugging I know I get the good coordinates), but it then crashes when I try to assign it to my event object's coordinates.

Below is the code and I've clearly commented with // <---------------- where it fails...

AppDelegate.h

#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>
#import <CoreLocation/CoreLocation.h>
#import "MapViewController.h"
#import "Event.h"

@interface AppDelegate : UIResponder <UIApplicationDelegate, MKMapViewDelegate, CLLocationManagerDelegate>{
    CLLocationManager *locationManager;
}

//-(void)makeTestData:(int)amount;
-(void) addressLocation:(NSString*)adres:(Event*)event;

@property (strong, nonatomic) UIWindow *window;
//@property (strong, nonatomic) NSMutableArray *events;


@end

AppDelegate.m

#import "AppDelegate.h"
#import "ListViewController.h"
#import "Event.h"
#import <RestKit/RestKit.h>


@implementation AppDelegate{
    NSMutableArray *events;

    /* for test data */
    NSMutableArray *titles;
}


@synthesize window = _window;
//@synthesize events;

-(void) addressLocation:(NSString*)adres: (Event*)event {
    NSString *urlString = [NSString stringWithFormat:@"http://maps.google.com/maps/geo?q=%@&output=csv&key=MYKEY", 
                           [adres stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
    NSString *locationString = [NSString stringWithContentsOfURL:[NSURL URLWithString:urlString]];
    NSArray *listItems = [locationString componentsSeparatedByString:@","];

    double latitude = 0.0;
    double longitude = 0.0;

    if([listItems count] >= 4 && [[listItems objectAtIndex:0] isEqualToString:@"200"]) {
        latitude = [[listItems objectAtIndex:2] doubleValue];
        longitude = [[listItems objectAtIndex:3] doubleValue];
    }
    else {
        //Show error
    }
    CLLocationCoordinate2D location;
    location.latitude = latitude;
    location.longitude = longitude;   // <----- Checked in debugging, coords are good

    event.coordinate.latitude = latitude;    // <----- can't assign the latitude here =/
    event.coordinate.longitude = longitude;  // <----- can't assign the longitude here =/

}

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{


    // START COMMUNICATOIN WITH REST INTERFACE
    //RKClient* client = [RKClient clientWithBaseURL:@"link"];
    //NSLog(@"I am your RKClient singleton : %@", [RKClient sharedClient]);
    // -------------------TEST OBJECTS
    //makeTestData(3);

    events = [NSMutableArray arrayWithCapacity:3];
    titles = [NSMutableArray arrayWithCapacity:3];
    [titles addObject:@"Gent Jazz Festival"];
    [titles addObject:@"Over blauw bloed en witte billenbijters - zoektocht in het Prinsenhof (zonder gids)"];
    [titles addObject:@"DuveltTent"];

    Event *event = [[Event alloc] init];
    event.title = [titles objectAtIndex:(rand()*100)%3];
    event.description = @"omminommie!!!";
    event.zone = @"fzfzefez";
    event.gemeente = @"Gent";
    event.plaats = @"";
    event.straat = @"Sint-Veerleplein";
    NSString *adres = [NSString stringWithFormat:@"%@, %@", event.gemeente, event.straat];
    [self addressLocation:adres:event];  //<---- This function fails, see above for def
    event.zone = @"blub";                
    [events addObject:event];            
...

---- EDIT
Like the code is, as above, it doesn't even compile and gives the error:

Expression is not assignable

When I use = location (which I did before) as suggested above I get the following error:

2012-07-13 17:14:20.608 Zone-It-new[565:707] -[Event setCoordinate:]: unrecognized selector sent to instance 0x283ab0
2012-07-13 17:14:20.621 Zone-It-new[565:707] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[Event setCoordinate:]: unrecognized selector sent to instance 0x283ab0'
*** First throw call stack:
(0x3748488f 0x35189259 0x37487a9b 0x37486a83 0x373e1650 0x6a319 0x6a5c9 0x31190cab 0x3118a7dd 0x31158ac3 0x31158567 0x31157f3b 0x33b9a22b 0x37458523 0x374584c5 0x37457313 0x373da4a5 0x373da36d 0x3118986b 0x31186cd5 0x6a097 0x6a03c)
terminate called throwing an exception

Here are my event.h and event.m

event.h

#import <Foundation/Foundation.h>
#import <CoreLocation/CoreLocation.h>
#import <MapKit/MapKit.h>
#import <RestKit/RestKit.h>

@interface Event : NSObject <MKAnnotation>


// required property from mkanotation
@property (nonatomic, readonly) CLLocationCoordinate2D coordinate;

// Optional
@property (nonatomic, copy) NSString *title;
@property (nonatomic, copy) NSString *description;
@property (nonatomic, copy) NSString *zone;
@property (nonatomic, assign) NSString *gemeente;
@property (nonatomic, copy) NSString *straat;
@property (nonatomic, assign) int deelnemers;
@property (nonatomic, copy) NSDate *start;
@property (nonatomic, copy) NSDate *einde;
@property (nonatomic, copy) NSString *plaats;
@property (nonatomic, readonly) int id_nr;
@property (nonatomic, assign) int huisnummer;

@end

event.m

#import "Event.h"

@implementation Event

@synthesize coordinate, title, zone, gemeente, straat, deelnemers, start, einde, plaats, id_nr, huisnummer, description;

@end

Important to note, maybe, is that ARC is on.

Answer 1

Have you tried changing the coordinate property to readwrite? (assign would be a good choice.)