如何以编程方式从 FileProvider Extension (macOS) 打开文件

Question

Is there a way to programmatically open a file from FileProvider Extension?

My use case is that I have FileProviderUI-extension for macOS which shows a dialog with 'Open file' button. And I'd like when user clicks on 'Open file' button to open the relevant file.

However, when I execute:

NSWorkspace.shared.open(itemURL)

a Finder error is shown: The application “MyAppAction (Finder)” does not have permission to open “My File.txt.”

I guess this is related to FileProviderExtension being sandboxed, but is there a way to open FileProvider files programmatically?

Answer 1

Here is an example on how to open a FileProvider folder:

1. Retrieve FileProvider root folder URL:

let fileProviderFolderURL = try! await NSFileProviderManager(for: SREG.context.domain)?.getUserVisibleURL(for: .rootContainer)

2. Use NSOpenPanel to ask user where to store the symbolic link to FileProvider root folder. Then store bookmark data of user-selected location and create symbolic link to FileProvider root within that location.

let savePanel = NSOpenPanel()
savePanel.canChooseDirectories = true
savePanel.title = "Choose this location"
savePanel.prompt = "Choose"

let result = await savePanel.begin()

if result == NSApplication.ModalResponse.OK {
    let panelURL = savePanel.url
    let mountBookmarkData = try! panelURL.bookmarkData(options: .withSecurityScope)
    UserDefaults.standard.set(mountBookmarkData, forKey: "aliasLocationBookmarkData")

    let fileManager = FileManager.default
    var aliasURL = panelURL.appendingPathComponent("MyRoot")

    UserDefaults.standard.set(aliasURL.path, forKey: Constants.UserDefaults.aliasPath)

    do {
        try fileManager.createSymbolicLink(at: aliasURL, withDestinationURL: fileProviderFolderURL)
    } catch {
        // handle error
    }

}

3. Later, when you want to open the Root folder in Finder, fetch bookmark data from UserDefaults and create URL from it. It is the location where symbolic link is stored. Start secure access on it and then open the symbolic link URL:

let aliasLocationBookmarkData = UserDefaults.standard.data(forKey: "aliasBookmarkData")!
var isStale = false
let aliasLocationURL = try URL(resolvingBookmarkData: aliasLocationBookmarkData, options: .withSecurityScope, relativeTo: nil, bookmarkDataIsStale: &isStale)

let securityScopeResult = aliasLocationURL.startAccessingSecurityScopedResource()
if securityScopeResult {
    let aliasPathKey = Constants.UserDefaults.aliasPath
    let aliasPath = UserDefaults.standard.string(forKey: aliasPathKey)
    let aliasURL = URL(fileURLWithPath: aliasPath)
    
    NSWorkspace.shared.open(aliasURL)    

    aliasLocationURL.stopAccessingSecurityScopedResource()
}

That's pretty much it. The key is to store bookmark data of the location user picked in NSOpenPanel dialog, create symbolic link in it and then you'll be able to access that resource even after app relaunch.