the filename property of NSOpenPanel is deprecated, what else to use?

This works just fine, but I get a deprecation warning on filename. I haven't found 开发者_StackOverflow社区an alternative though, is there one?

filePath = [[zOpenPanel filename] retain]

filename Returns the absolute pathname of the file currently shown in the panel. (Deprecated in Mac OS X v10.6. Use URL instead.)

URL Returns the absolute pathname of the file currently shown in the panel as a URL.

• (NSURL *)URL

So, I think filePath = [[zOpenPanel URL] retain]