method called in document.m on closing of document

Question

i use - (void)windowControllerDidLoadNib:(NSWindowController *)aController to see when a document has been loaded in a document based application. But what method should I use to see when a document is beeing closed? i would like to save the content of a textbox to the NSUserDefaults but i am unable to find a method that is called whenever the document is closing. i searched the web and also trough the methods that appear as hint in xcode but without luck! any help appreciated!

thanks

Answer 1

I observe NSApplicationWillTerminateNotification and override the [NSDocument close] method to perform document clean-up ([NSDocument close] isn't called when the app terminates!)

MyDocument.h:

@interface MyDocument : NSDocument
{
    BOOL _cleanedUp;    // BOOL to avoid over-cleaning up
    ...
}

@end

MyDocument.m:

// Private Methods
@implementation MyDocument ()

- (void)_cleanup;

@end

@implementation MyDocument

- (id)init
{
    self = [super init];
    if (self != nil)
    {
        _cleanedUp = NO;

        // Observe NSApplication close notification
        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(_cleanup)
                                                     name:NSApplicationWillTerminateNotification
                                                   object:nil];
    }
    return self;
}

- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];

    // I'm using ARC so there is nothing else to do here
}

- (void)_cleanup
{
    if (!_cleanedUp)
    {
        _cleanedUp = YES;
        logdbg(@"Cleaning-up");

        // Do my clean-up
    }
}

- (void)close
{
    logdbg(@"Closing");

    [self _cleanup];

    [super close];
}