If I use [UTType exportedTypeWithIdentifier:] to get one of the types in my app's Info.plist, and then ask for the preferredFilenameExtension of that UTType, I get the wrong extension, i.e., not the first file extension listed for that UTI in my Info.plist. Is this one of those situations where AppKit is looking in some database that can get out of sync with what's actually in the Info.plist?
@DTS Engineer,
Can you provide the type declaration portion of your Info.plist?
When you ask for the type declaration portion, I'm going to assume you mean UTExportedTypeDeclarations, not UTImportedTypeDeclarations or CFBundleDocumentTypes. Even just UTExportedTypeDeclarations is too much text to fit in a forum reply. So here's just the part for the file type in question.
<dict>
<key>UTTypeConformsTo</key>
<array>
<string>public.data</string>
<string>public.composite-content</string>
</array>
<key>UTTypeDescription</key>
<string>FrameForge previsualization</string>
<key>UTTypeIconFile</key>
<string>document.icns</string>
<key>UTTypeIcons</key>
<dict/>
<key>UTTypeIdentifier</key>
<string>com.frameforge3d.frameforge.previsualization</string>
<key>UTTypeTagSpecification</key>
<dict>
<key>public.filename-extension</key>
<array>
<string>previz</string>
<string>s3d</string>
</array>
</dict>
</dict>