How to change a deprecated beginSheetForDirectory method

I have an app that was using beginSheetForDirectory:file:modalForWindow:modalDelegate:didEndSelector:contextInfo:.

I checked Apple documentation which said it's deprecated and to use another method instead:

Presents a Save panel as a sheet with a specified path and, optionally, a specified file in that path. (Deprecated in Mac OS X v10.6. Use beginSheetModalForWindow:completionHandler: instead.)

My question is how to change this code to the new one?

//  [savePanel setRequiredFileType:@"png"];
[savePanel beginSheetForDirectory:nil 
                             file:nil  
                   modalForWindow:[self window] 
                    modalDelegate:self 
                   didEndSelector:@selector(didEndSaveSheet:returnCode:conextInfo:) 
                      contextInfo:NULL];

Solution

You're looking for the beginSheetModalForWindow:completionHandler: method.

Example:

NSSavePanel *savePanel = [NSSavePanel savePanel];

[savePanel beginSheetModalForWindow:_window completionHandler:^(NSInteger result) {
    if (result == NSFileHandlingPanelOKButton) {
        NSURL *savePath = [[savePanel URLs] objectAtIndex:0];
    } else {
        [savePanel close];
    }
}];