Question

I’d like to run the code [tableView reloadData], except I want to call it from a seperate class to the view controller I want to reload the data in.

(Note. If there is something more effective to reload a tableview than reloadData, chime in).

Say the view I want to reload is ‘RootViewController’, and I am currently in ‘DetailViewController’, what do i need to do to make it work.

My best attempt right now is [RootViewController.tableView reloadData], but its not right.
(I get error: expected ‘:’ before . token.

Regards, @norskben

Answer 1

You can use notifications or a protocol.

Using notifications:

post a notification just after finishing saving the data and before returning from the method. Something like this:

// post notification
[[NSNotificationCenter defaultCenter] postNotificationName:@”DataSaved” object:nil];

In the controller handling the table, implement

- (void) dataSaved:(NSNotification *)notification{

    [self.tableView reloadData];

}

and in its viewDidLoad method add the following code to register for notifications:

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

finally, unregister in the dealloc method adding

[[NSNotificationCenter defaultCenter] removeObserver:self];

Using a protocol:

start creating a protocol with a callback that your previous controller can use.

@protocol dataSavedDelegate
-(void)dataSaved;
@end

once you finish saving your data:

[(id< dataSavedDelegate >)object dataSaved];

now, in your previous controller you handle the delegate method: in the dataSaved() method you reload your table.