I have a simple document-based Cocoa app call "RaiseMan". When I go to save a file, this message appears in the console:
-[NSDocumentController fileExtensionsFromType:] is deprecated, and does not work when passed a uniform type identifier (UTI). If the application didn't invoke it directly then the problem is probably that some other NSDocument or NSDocumentController method is getting confused by a UTI that's not actually declared anywhere. Maybe it should be declared in the UTExportedTypeDeclarations section of this app's Info.plist but is not. The alleged UTI in question is "com.bignerdranch.raiseman-doc".
If I save the current file as, say, "Test", it turns out a file that opens as a .plist, and does not open with the Raiseman app. If I save it as "Test.rsmn" (explicitly typing the extension), it saves it as a Raiseman-type file, but when I re-open the file, I cannot access any user preferences or the preferences panel (.xib).
Context:I am currently working my way through Aaron Hillegass's Programming for Mac OS X, Chapter 13...
So, in order to achieve desired results I made sure that under the Properties inspector for the project Targets, the Identifier and UTI type (in the Document Type table), as well as the UT Type identifier in the .plist file were all the same <key>UTTypeIdentifier</key>
<string>"com.yourDomainName.ProductName"</string>.