Question

I have table view navigation controller and the data is loaded from url. I created a thread in order to keep the user in table view in Second Level view controller. The problem is that the second level view controller loads url each time the view is opened, even if it has already been opened before. How can I make it load the data only once?

Answer 1

When you load the data within viewWillAppear: (or viewDidAppear:) then move the code to viewDidLoad.

You can also set a timestamp within your loading procedure.

self.lastUpdateDate = [NSDate date];

When the program enters the loading code, you can check after the last update date:

if([[NSDate date] timeIntervalSinceDate:self.lastUpdateDate] <= 300) {
  //if the lastupdate was no longer then 5 minutes ago, don't update
}
else {
  // do some web loading stuff
}