viewForOverlay is not getting called - iphone

Question

I want to draw route between two path on map in ios. The problem is that the mapView:viewforoverlay is no getting called.
Here is my code complete code. There is no problem in parsing as i have tested it using the NSLog statement. I have customized the code from here : http://spitzkoff.com/craig/?p=136
Thanks to this website. bt please help me out.
#import "AppViewController.h"
#import "XMLParser.h"
#import "AppAppDelegate.h"
#interface AppViewController ()
#end
#implementation AppViewController
#synthesize mapview= _mapview;
#synthesize routeLine = _routeLine;
#synthesize routeLineView = _routeLineView;
#synthesize coordinatearray = _coordinatearray;
#synthesize pathlatandlong = _pathlatandlong;
#synthesize coordinate = _coordinate;
- (void)viewDidLoad
{
[super viewDidLoad];
[self doParse];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)viewDidUnload
{
[self setMapview:nil];
[super viewDidUnload];
// Release any retained subviews of the main view.
}
- (BOOL)shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}
-(void)doParse
{
[_coordinatearray removeAllObjects];
NSURL *parseurl = [[NSURL alloc] initWithString:#"https://maps.google.com/maps?f=d&hl=en&saddr=19.055229,72.830829&daddr=19.113611,72.871389&ie=UTF8&om=0&output=kml"];
NSXMLParser *nsxmlparser = [[NSXMLParser alloc] initWithContentsOfURL:parseurl];
XMLParser *parser = [[XMLParser alloc] initXMLParser];
[nsxmlparser setDelegate:parser];
BOOL success = [nsxmlparser parse];
if(success)
{
[self loadRoute];
if (nil != self.routeLine)
{
[self.mapview addOverlay:self.routeLine];
}
// zoom in on the route.
[self zoomInOnRoute];
}
}
-(void) loadRoute
{
AppAppDelegate *obj = (AppAppDelegate*)[[UIApplication sharedApplication] delegate];
NSArray* pointStrings = [obj.parsedxmldata componentsSeparatedByString:#" "];
// while we create the route points, we will also be calculating the bounding box of our route
// so we can easily zoom in on it.
MKMapPoint northEastPoint;
MKMapPoint southWestPoint;
// create a c array of points.
MKMapPoint* pointArr = malloc(sizeof(CLLocationCoordinate2D) * pointStrings.count);
for(int idx = 0; idx < pointStrings.count-1; idx++)
{
// break the string down even further to latitude and longitude fields.
NSString* currentPointString = [pointStrings objectAtIndex:idx];
NSArray* latLonArr = [currentPointString componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:#","]];
CLLocationDegrees latitude = [[latLonArr objectAtIndex:1] doubleValue];
CLLocationDegrees longitude = [[latLonArr objectAtIndex:0] doubleValue];
NSLog(#"%f %f" , latitude , longitude);
// create our coordinate and add it to the correct spot in the array
CLLocationCoordinate2D coordinate = CLLocationCoordinate2DMake(latitude, longitude);
MKMapPoint point = MKMapPointForCoordinate(coordinate);
//
// adjust the bounding box
//
// if it is the first point, just use them, since we have nothing to compare to yet.
if (idx == 0)
{
northEastPoint = point;
southWestPoint = point;
}
else
{
if (point.x > northEastPoint.x)
northEastPoint.x = point.x;
if(point.y > northEastPoint.y)
northEastPoint.y = point.y;
if (point.x < southWestPoint.x)
southWestPoint.x = point.x;
if (point.y < southWestPoint.y)
southWestPoint.y = point.y;
}
pointArr[idx] = point;
}
// create the polyline based on the array of points.
self.routeLine = [MKPolyline polylineWithPoints:pointArr count:pointStrings.count];
_routeRect = MKMapRectMake(southWestPoint.x, southWestPoint.y, northEastPoint.x - southWestPoint.x, northEastPoint.y - southWestPoint.y);
}
-(void) zoomInOnRoute
{
[self.mapview setVisibleMapRect:_routeRect];
}
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
}
- (void)dealloc
{
self.mapview = nil;
self.routeLine = nil;
self.routeLineView = nil;
}
- (MKOverlayView *)mapView:(MKMapView *)map viewForOverlay:(id <MKOverlay>)overlay
{
MKOverlayView* overlayView = nil;
NSLog(#"Inside viewforoverlay");
if(overlay == self.routeLine)
{
//if we have not yet created an overlay view for this overlay, create it now.
if(nil == self.routeLineView)
{
self.routeLineView = [[MKPolylineView alloc] initWithPolyline:self.routeLine];
self.routeLineView.fillColor = [UIColor redColor];
self.routeLineView.strokeColor = [UIColor redColor];
self.routeLineView.lineWidth = 3;
}
overlayView = self.routeLineView;
}
return overlayView;
}
#end

Answer 1

Make sure the delegate for the mapView is set to your controller, either in the XIB or programmatically as follows:
- (void)viewDidLoad
{
[super viewDidLoad];
[_mapview setDelegate:self];
[self doParse];
// Do any additional setup after loading the view, typically from a nib.
}