SwiftUIでZIPをシェアすると大量にワーニングが出ます。
シェアが動かないわけではないけどとても不満。

Failed to request default share mode for fileURL:file:///
Only support loading options for CKShare and SWY types.
error fetching item for URL:file:///
error fetching file provider domain for URL:file:///
Collaboration: error loading metadata for documentURL:file:///

問題のコード

コードはよくあるSheetにフラグを立ててモーダル起動してダウンロードするパターン。
ボタンを押す方法だとiOS16からShareLinkもあるけど、他の機能からフラグ立てたり汎用的なのはこのパターン。

ContentView.swift

import SwiftUI

struct ContentView: View {
  @State var isPresented = false
  let zipFile = Bundle.main.url(forResource: "tmp", withExtension: "zip")!
  var body: some View {
    VStack {
      Button(action: { isPresented = true } , label: {
        Text("Download Zip")
      })
    }
    .padding()
    .sheet(isPresented: $isPresented, content: {
      ZipDownloadView(zipFile: zipFile)
    })
  }
}
struct ZipDownloadView: UIViewControllerRepresentable {
  let zipFile: URL
  
  func makeUIViewController(context: Context) -> UIActivityViewController {
    let activity = UIActivityViewController(activityItems: [zipFile], applicationActivities: nil)
    return activity
  }
  func updateUIViewController(_ uiViewController: UIActivityViewController, context: Context) {}
}

解決方法

META情報を付与してやれば解決。

ContentView.swift

import SwiftUI
import LinkPresentation

struct ContentView: View {
  @State var isPresented = false
  let zipFile = Bundle.main.url(forResource: "tmp", withExtension: "zip")!
  var body: some View {
    VStack {
      Button(action: { isPresented = true } , label: {
        Text("Download Zip")
      })
    }
    .padding()
    .sheet(isPresented: $isPresented, content: {
      ZipDownloadView(zipFile: zipFile)
    })
  }
}
struct ZipDownloadView: UIViewControllerRepresentable {
  let zipFile: URL
  
  func makeUIViewController(context: Context) -> UIActivityViewController {
    let metaData = getMetadataForSharingManually(title: "zipFile Sharering", url: zipFile, fileName: zipFile.lastPathComponent, fileType: "zip")
    let metadataItemSource = LinkPresentationItemSource(metaData: metaData)
    let activity = UIActivityViewController(activityItems: [metadataItemSource], applicationActivities: nil)
    return activity
  }
  
  func updateUIViewController(_ uiViewController: UIActivityViewController, context: Context) {}
  
  func getMetadataForSharingManually(title: String, url: URL, fileName: String, fileType: String) -> LPLinkMetadata {
    let linkMetaData = LPLinkMetadata()
    let path = Bundle.main.path(forResource: fileName, ofType: fileType)
    linkMetaData.iconProvider = NSItemProvider(contentsOf: URL(fileURLWithPath: path ?? ""))
    linkMetaData.originalURL = url
    linkMetaData.title = title
    return linkMetaData
  }
}

// Reference: https://medium.com/better-programming/whats-new-in-sharing-for-ios-13-3216999ff942
class LinkPresentationItemSource: NSObject, UIActivityItemSource {
  var linkMetaData = LPLinkMetadata()
  
  func activityViewControllerLinkMetadata(_ activityViewController: UIActivityViewController) -> LPLinkMetadata? {
    return linkMetaData
  }
  
  func activityViewControllerPlaceholderItem(_ activityViewController: UIActivityViewController) -> Any {
    return "Placeholder"
  }
  
  func activityViewController(_ activityViewController: UIActivityViewController, itemForActivityType activityType: UIActivity.ActivityType?) -> Any? {
    return linkMetaData.originalURL
  }
  
  init(metaData: LPLinkMetadata) {
    self.linkMetaData = metaData
  }
}

このエラーは消えなかった

シュミレータでは表示するが、実機では出ないのでまぁいいかな…

Error acquiring assertion: <Error Domain=RBSServiceErrorDomain Code=1 "(originator doesn't have entitlement com.apple.runningboard.primitiveattribute AND originator doesn't have entitlement com.apple.runningboard.assertions.frontboard AND target is not running or doesn't have entitlement com.apple.runningboard.trustedtarget AND Target not hosted by originator)" UserInfo={NSLocalizedFailureReason=(originator doesn't have entitlement com.apple.runningboard.primitiveattribute AND originator doesn't have entitlement com.apple.runningboard.assertions.frontboard AND target is not running or doesn't have entitlement com.apple.runningboard.trustedtarget AND Target not hosted by originator)}>