Question

I’m using the kmlviewer example from Apple but it takes the kml file from a local diretory. What I want to do is call that file remotely using an url.

This is the original code from Apple:

NSString *path = [[NSBundle mainBundle] pathForResource:@"KML_Sample" ofType:@"kml"];
NSURL *url = [NSURL fileURLWithPath:path];
kmlParser = [[KMLParser alloc] initWithURL:url];
[kmlParser parseKML];

How can I call a remote file which is in an url as: http://www.domain.com/route.kml ?

Best regards.

Answer 1

MapViewController.h :

    .....
    NSMutableData   *webData;
    KMLParser       *kml;
    .....
    @property (nonatomic, retain) NSMutableData   *webData;

MapViewController.m :

- (IBAction)showKmlData:(id)sender  //Let's say you want to download kml data with a button tap, you create a method for that (you may not act like this, but the content is the same):
{
    NSURL *path = [NSURL URLWithString:@"http://www.domain.com/route.kml"];
    NSURLRequest *request = [[NSURLRequest alloc] initWithURL:path];
    NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];

    [connection release];
    [request release];
}

-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
   self.webData =[NSMutableData data];
}


-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{   
    [webData appendData:data];
}

-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
    NSString *fileName = [[[NSURL URLWithString:kmlStr] path] lastPathComponent];
    //NSString *fileName = @"route.kml"; 
    NSArray *pathArr = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *folder = [pathArr objectAtIndex:0];

    NSString *filePath = [folder stringByAppendingPathComponent:fileName];
    NSURL *fileURL = [NSURL fileURLWithPath:filePath];  
    NSError *writeError = nil;

    [webData writeToURL: fileURL options:0 error:&writeError];

    if( writeError) {
        NSLog(@" Error in writing file %@' : \n %@ ", filePath , writeError );
        return;
    }

    kml = [[KMLParser parseKMLAtPath:filePath] retain];

    NSArray *annotations = [kml points];

    if ([[mapview overlays] count] == 0) {
        [mapview addAnnotations:annotations];

        NSArray *overlays = [kml overlays];
        [mapview addOverlays:overlays];
        MKMapRect flyTo = MKMapRectNull;

        for (id <MKOverlay> overlay in overlays) {
            if (MKMapRectIsNull(flyTo)) {
                flyTo = [overlay boundingMapRect];
            } else {
                flyTo = MKMapRectUnion(flyTo, [overlay boundingMapRect]);
            }
        }

        for (id <MKAnnotation> annotation in annotations) {
            MKMapPoint annotationPoint = MKMapPointForCoordinate(annotation.coordinate);
            MKMapRect pointRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0, 0);
            if (MKMapRectIsNull(flyTo)) {
                flyTo = pointRect;
            } else {
                flyTo = MKMapRectUnion(flyTo, pointRect);
            }
        }

        mapview.visibleMapRect = flyTo;
    }

    [mapview addAnnotations:annotations];
    NSArray *overlays = [kml overlays];
    [mapview addOverlays:overlays];
}

-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error!" message:@"An error has occured." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
    [alert show];
    [alert release];
}