保存 UIDocument 失败并出现权限错误 - `NSCocoaErrorDomain` 代码 `513`

Question

我正在尝试构建 iOS 具有与 Pages / Numbers / Keynote 类似行为的应用程序。这些应用程序中的每一个都是基于文档的应用程序，用户首先会看到 UIDocumentBrowserViewController，用户可以在其中选择要在应用程序中打开的文档。例如，在 Numbers 中，用户可以 select 一个 .numbers 文件并且它会打开，或者用户可以 select 一个 .csv 并且它会将这个 csv 文件导入一个数字文件它与原始 csv 一起保存在同一位置。

在我的应用程序中，我希望用户 select 一个 .csv 文件，然后我将其导入我自己的文档格式（称为 .pivot）并将其保存在旁边csv 文件（就像数字一样。）这在模拟器中运行良好，但是当我运行我在设备上的代码时，在我的自定义 Pivot 文档上调用 save(to:for:completionHandler:) 时出现错误。

我的文档浏览器代码如下

class DocumentBrowserViewController: UIDocumentBrowserViewController, UIDocumentBrowserViewControllerDelegate {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        delegate = self
        
        allowsDocumentCreation = false
        allowsPickingMultipleItems = false
    }
    
    func documentBrowser(_ controller: UIDocumentBrowserViewController, didPickDocumentsAt documentURLs: [URL]) {
        guard let sourceURL = documentURLs.first else { return }
        
        if sourceURL.pathExtension == "csv" {
            
            // Create a CSV document so we can read the CSV data
            let csvDocument = CSVDocument(fileURL: sourceURL)
            csvDocument.open { _ in
                
                guard let csv = csvDocument.csvData else {
                    fatalError("CSV is nil upon open")
                }
                
                // Create the file at the same location as the csv, with the same name just a different extension
                var pivotURL = sourceURL.deletingLastPathComponent()
                let pivotFilename = sourceURL.lastPathComponent .replacingOccurrences(of: "csv", with: "pivot")
                pivotURL.appendPathComponent(pivotFilename, isDirectory: false)
                
                let model = PivotModel()
                model.csv = csv
                let document = PivotDocument(fileURL: pivotURL)
                document.model = model
                
                document.save(to: pivotURL, for: .forCreating, completionHandler: { success in
                    
                    // `success` is false here
                    
                    DispatchQueue.main.async {
                        self.performSegue(withIdentifier: "presentPivot", sender: self)
                    }
                })
            }
        }
    }
    
}

我的第一个UIDocument加载csv文件的子类如下。

import SwiftCSV // This is pulled in using SPM and works as I expect, so is unlikely causing this problem 

class CSVDocument: UIDocument {
    
    var csvData: CSV?
    
    override func contents(forType typeName: String) throws -> Any {
        return Data()
    }
    
    override func load(fromContents contents: Any, ofType typeName: String?) throws {
        guard let data = contents as? Data else {
            fatalError("No file data")
        }
        
        guard let string = String(data: data, encoding: .utf8) else {
            fatalError("Cannot load data into string")
        }
        
        csvData = try CSV(string: string)
    }
}

我的自定义数据透视文档的第二个 UIDocument 子类如下。通过覆盖 handleError() 函数，我可以看到保存失败并在 NSCocoaErrorDomain 中出现错误，代码为 513.

class PivotDocument: UIDocument {
    
    var model: PivotModel!
    var url: URL!
    
    override func contents(forType typeName: String) throws -> Any {
        let encoder = JSONEncoder()
        return try encoder.encode(model)
    }
    
    override func load(fromContents contents: Any, ofType typeName: String?) throws {        
        guard let data = contents as? Data else {
            fatalError("File contents are not Data")
        }
        
        let decoder = JSONDecoder()
        model = try decoder.decode(PivotModel.self, from: data)
    }
    
    override func handleError(_ error: Error, userInteractionPermitted: Bool) {
        let theError = error as NSError
        
        print("\(theError.code)") // 513
        print("\(theError.domain)") // NSCocoaErrorDomain
        print("\(theError.localizedDescription)") // “example.pivot” couldn’t be moved because you don’t have permission to access “CSVs”.
        
        super.handleError(error, userInteractionPermitted: userInteractionPermitted)
    }
}

这在模拟器中有效（我的用户可以访问所有文件系统）但在 iOS 中无效（用户和应用程序权限不同）这一事实让我觉得我有一个权限问题。例如，我是否需要在我的 Xcode 项目中声明一些权利？

或者我只是误用了 UIDocument API 并且我需要找到不同的实现方式吗？

Answer 1

我找到了我正在寻找的功能，它复制了 iWork 应用程序的功能！

UIDocumentBrowserViewController 有这个功能 importDocument(at:nextToDocumentAt:mode:completionHandler:)。来自文档：

Use this method to import a document into the same file provider and directory as an existing document. For example, to duplicate a document that's already managed by a file provider: Create a duplicate of the original file in the user's temporary directory. Be sure to give it a unique name. Call importDocument(at:nextToDocumentAt:mode:completionHandler:), passing in the temporary file's URL as the documentURL parameter and the original file's URL as the neighborURL parameter.

所以 documentBrowser(_:didPickDocumentsAt:) 现在是：

let pivotFilename = sourceURL.lastPathComponent .replacingOccurrences(of: "csv", with: "pivot")

let path = FileManager.default.temporaryDirectory.appendingPathComponent(pivotFilename)
if FileManager.default.createFile(atPath: path.path, contents: nil, attributes: nil) {
    
    self.importDocument(at: path, nextToDocumentAt: sourceURL, mode: .copy) { (importedURL, errorOrNil) in
        guard let pivotURL = importedURL else {
            fatalError("No URL for imported document. Error: \n \(errorOrNil?.localizedDescription ?? "NO ERROR")")
        }
    
        
        let model = PivotModel()
        model.csv = csv
        let document = PivotDocument(fileURL: pivotURL)
        document.model = model
        
        DispatchQueue.main.async {
            self.performSegue(withIdentifier: "presentPivot", sender: self)
        }
    }
}
else {
    fatalError("Could not create local pivot file in temp dir")
}

没有更多的权限错误。希望这对以后的其他人有所帮助。

保存 UIDocument 失败并出现权限错误 - `NSCocoaErrorDomain` 代码 `513`

Saving UIDocument fails with permissions error - `NSCocoaErrorDomain` code `513`

xcode

ios

icloud

uidocument

swift