Question

I’m very much new to objective C. I have a case where I need to send request to the server URL at regular intervals. I made a asynchronous URL connection and used a NSTimer function to call the viewWillAppear function.

 - (void)viewWillAppear:(BOOL)animated
  {
       [super viewWillAppear:animated];
       NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL    URLWithString:@"myurl/test.csv"] cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:15.0];

       NSURLConnection *connection= [[NSURLConnection alloc] initWithRequest:request delegate:self];

       if(connection){
          label.text = @"connecting...";
        }else{
         //
        }


    }

 -(void)connection :(NSURLConnection *) connection didReceiveData:(NSData *)data{
     [self viewWillAppear:TRUE];
      response = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
      NSLog(response);
      }

I used the following NSTimer method to call the viewWillAppear method.

- (void)checkURLRequest
    {
     [self setProgressTimer:[NSTimer
                        scheduledTimerWithTimeInterval:(1.0f / 30.0f) 
                        target:self 
                        selector:@selector(viewWillAppear:) 
                        userInfo:self 
                        repeats:TRUE]];
    }

   - (void)setProgressTimer:(NSTimer *)theTimer
    {
    [_progressTimer invalidate];
     _progressTimer = theTimer;
    }

Is my approach even correct? Because when i updated the file ‘test.csv’ on the server, it can’t do a live update as and when the file changes its still logging the old values in the file.

Answer 1

I would move all the URL connection stuff outside the VC and into a custom class that does this using blocks. This would allow you to use this in other classes and is better OO programming. I can send you an example I use with image loading if you need it.