Question

After reading a bunch of stackoverflow posts and forums I got really confused on this subject. Alot speak about using delegates, but can result in memory problem if there is a big amount of data.

I am only to handle around 600-bytes of data from a TCP/IP device and override the existing value with the new.

I have made a RootViewController which has a special view and the TCP/IP socket, furthermore I have two other ViewControllers which has to use data from the RootViewController (TCP/IP).

Should I perhaps make a seperate class for the TCP stuff instead of mixing it up in my RootViewController?

Also how should I handle the sharing of data across the ViewControllers?

Thanks in advance.

Answer 1

For sharing data among classes you can use notifications mechanism. Post a notification in your FromClass.m:

NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:yourTCPData, @"TCPData", nil];
[[NSNotificationCenter defaultCenter] postNotificationName:@"gotTCPData" object:nil userInfo:options];

In your ToClass.m viewDidLoad add this:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(makeSomeThingUsefulWithTCPData:)name:@"gotTCPData" object:nil];

…and somewhere in your ToClass.m add this method:

- (void)makeSomeThingUsefulWithTCPData:(NSNotification *)notification {
  NSDictionary *dict = [notification userInfo];
  yourTCPDataClass *yourTCPDataObject = [dict objectForKey:@"TCPData"];
  // Here make something useful with your TCP data
  }

Also add this in your ToClass.m viewDidUnload to release observer object when view will be unloaded:

[[NSNotificationCenter defaultCenter] removeObserver:self];