I’m working with a custom exported type in my macOS app when I found that SwiftUI’s ShareLink would not display any options for sharing. Currently, I have a type that conforms to public.data and public.json, with a unique identifier and file extension too.

Here’s an image of the empty share sheet.

After searching through the documentation on Uniform Type Identifiers, I found this written about the content type.

For document types, conform to public.content, either directly or by conforming to a type that already conforms to public.content. This conformance allows users to share your type over AirDrop.

This seems to be untrue in my context, so I assume that I have made a mistake.

Here’s my current transferable conformance:

extension Quote: Transferable {
    static var transferRepresentation: some TransferRepresentation {
        CodableRepresentation(contentType: .quote)
    }
}

extension UTType {
    // Real type identifier is not com.example, of course
    static var quote: UTType { UTType(exportedAs: "com.example.quote") }
}

And declarations of exported type identifiers and document types are here.

This is also what the ShareLink looks like:

ShareLink(
    item: Quote(text: "In a galaxy far far away..."),
    preview: SharePreview("An intersting quote"),
    label: { Image(systemName: "square.and.arrow.up") }
)

Does anyone know why this issue with no share options is occurring with this custom exported type identifier?