Delete An NSMutableArray from another Class in C-Objective? - objective-c

Question

I need help with delete an array with a button from the SecondViewController in the view controller class.
At the moment I have this:
- (IBAction)deleteArrayFromSeconViewController:(id)sender // is the Button which should
// delete the array
{
self.textLabel2.text = #""; // this work fine
ViewController *vc = [[ViewController alloc]init];
[vc.textViewArray removeAllObjects]; // do not remove the objects?
}
What should I do to overtake an order from the SecondViewControllerClass in the ViewControllerClass?
I tried also this in the SecondViewControllerClass:
- (IBAction)deleteArrayFromSeconViewController:(id)sender
{
self.textLabel2.text = #"";
ViewController *vc = [[ViewController alloc]init];
[vc deleteTheArray];
}
to call this function in the ViewControllerClass:
- (void) deleteTheArray
{
[textViewArray removeAllObjects];
}

Answer 1

I'm not at all sure that this is the best way to do this, but you could post a custom NSNotification in your first view controller, and then pick it up in your second. Code Example:
//Post in your first view controller when wanting to delete the array
[[NSNotificationCenter defaultCenter] postNotificationName:#"DeleteArrayNotification" object:nil userInfo:nil /*include any items your reciever might wish to access*/];
and then in your second view controller, you could add yourself as an observer in the -(void)awakeFromNib Method. Put in your awake from nib method:
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(deleteArrayNotification:) name:#"DeleteArrayNotification" object:nil];
And then implement the deleteArrayNotification: method:
- (void)deleteArrayNotification:(NSNotification *)notification {
[array removeAllObjects];
[array release]; //Delete this line if your project is using ARC
}
I am highly doubtful that this is good coding practice to implement NSNotification like this, but I thought it might be of use!
More information can be found under the Apple developer documentation, under NSNotification and NSNotificationCenter.
Hope I can help!
Ben