Question

How can I reload a UITableView without noticing the user behind the iDevice?

I’m updating my UITableViews datasource in -applicationWillEnterForeground: by sending a notification to my RootViewController that observes the notification and runs a selector that calls [self.table reloadData] but I want this update to be made in stealth and not showed to the user.

It seems that -viewWillAppear: is fired before -applicationWillEnterForeground:

Answer 1

I’m a little confused by your question, but I think what you’re looking for is a way to reload the data before it appears on screen, yes?

I’d say figure out a way to call your data refresh method directly, not via a notification. The notification de-couples the data refresh from -applicationWillEnterForeground, giving the view time to appear.

Sequence is probably something like this:

1. applicationWillEnterForeground
2. viewWillAppear
3. The view appears.

4. Notification observer method is called

   a) Notification observer method calls [self.table reloadData]

5. Table view refreshes on-screen.

What you want is to couple your notification method to a method that gets called before the view appears. Call it directly from applicationWillEnterForeground or viewWillAppear.

That way it’ll play out like this:

1. applicationWillEnterForeground

   a) your data refresh method is called. (no need to call [self.table reloadData], the tableView hasn’t loaded the data at all yet.)

2. viewWillAppear
3. The view appears.
4. Table view is loaded with already refreshed data.

or like this:

1. applicationWillEnterForeground

2. viewWillAppear

   a) your data refresh method is called. (no need to call [self.table reloadData], the tableView hasn’t loaded the data at all yet.)

3. The view appears.
4. Table view is loaded with already refreshed data.