Passing values from custom NSView to NSCollectionViewItem

I have an NSTabView inside my custom NSView that is used as the prototype for the NSCollectionView. In the second tab I have NSButton button and NSImageView objects.

NSButton is a "Browse" button that triggers the NSOpenPanel.

I have connected the button's selector to IBAction in MyCustomView which performs the following:

// MyView.h

@interface MyView : NSView 
{
    IBOutlet NSTabView *tabView;
    IBOutlet NSImageView *myImageView;
    IBOutlet NSButton *browseButton;
}

-(IBAction)openBrowseDialog:(id)sender;


@end


// MyView.m

-(IBAction)openBrowseDialog:(id)sender
{

    NSOpenPanel* openDlg = [NSOpenPanel openPanel];

    [openDlg setCanChooseFiles:YES];
    [openDlg setCanChooseDirectories:NO];
    [openDlg setAllowsMultipleSelection:NO];
    [openDlg setAllowedFileTypes:[NSArray arrayWithObjects:@"png", @"jpg", @"jpeg", @"gif", nil]];


    if ( [openDlg runModal] == NSOKButton )
    {

        NSArray* files = [openDlg URLs];
        NSURL* fileURL = [files objectAtIndex:0];
        NSData *imageData = [NSData dataWithContentsOfURL:fileURL];

        if( imageData != nil )
        {
            NSImage *image = [[NSImage alloc] initWithData:imageData];
            myImageView.image = 开发者_如何学JAVAimage;
            [image release];
        }

    }

}

When I run this "myImageView" traces "null" in the Console even though I connected it as IBOutlet in Interface Builder. Could you explain why? How should I do this instead? I also need to pass the "fileURL" value to "representedObject" in my NSCollectionViewItem object but I don't know how to access that from here?

I have finally achieved what I needed after a day of trouble-shooting. There were a couple of things wrong with my original approach:

1) Using NSTabView inside NSCollectionView appears to be a bad idea because bindings do not get initialized in "non-active" tabs. I scrapped that and opted for NSSegmentedControl instead with manual show/hide of objects.

2) All of the code in my original question should really go inside subclass of NSCollectionViewItem rather than into subclass of NSView, which I don't even need since I'm not doing custom drawing.

Now it's all good. I'm learning.