Optimal way to call PerformSelector- iOS

Question

I am calling method that call URL with different timetstamp. However, data processing may take longer than the time I have defined.

  [self performSelector:@selector(process) withObject:nil afterDelay:1.6];

below part shows the method is called

 -(void)process
{
    timestamp=[NSString stringWithFormat:@"%1.f",progressValue];
    NSString *contour=@"&bandschema=4";
    NSString *url6=[NSString stringWithFormat:@"http://contour.php?  callback=contourData%@&type=json&timestamp=%@%@",timestamp,timestamp,contour];        
    NSURL *url1=[NSURL URLWithString:url6];
  __weak ASIHTTPRequest *request1 = [ASIHTTPRequest requestWithURL:url1];
        [request1 setCompletionBlock:^{
            responseString = [request1 responseString];
                [self plotPoint:self.responseString];

        }];
        [request1 setFailedBlock:^{

            NSError *error=[request1 error];
            NSLog(@"Error: %@", error.localizedDescription);
        }];
        [request1 startAsynchronous];
    }

this part is start point of analyzing data.

-(void)plotPoint:(NSString *)request
{
    NSArray *polygonArray = [[dict  objectForKey:@"data"]valueForKey:@"polygon"];
    NSArray *valleyPolygonArray = [[dict objectForKey:@"valley"]valueForKey:@"polygon"];
    CLLocationCoordinate2D *coords;
}

However sometimes time interval is not enough to get new data especially when internet connection is not good.

Could you guide me please? How could I handle the problem? What is the optimal solution?

Answer 1

Can you provide some code? Basically you need to perform the action in the request finished delegate call

Some more info here: http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSURLConnection_Class/Reference/Reference.html

http://developer.apple.com/library/mac/#documentation/Foundation/Reference/NSURLConnectionDelegate_Protocol/Reference/Reference.html#//apple_ref/occ/intf/NSURLConnectionDelegate

EDIT:
I still don't quite understand, but see if that helps you:

__weak ASIHTTPRequest *request1 = [ASIHTTPRequest requestWithURL:url1];  
        [request1 setCompletionBlock:^{  
            responseString = [request1 responseString];  
                [self plotPoint:self.responseString];  

        //if (something)  
            [self process];  
        }];