在macOS 10.12+中接收承诺的电子邮件 [英] Receive promised e-mail in macOS 10.12+
问题描述
以前，我使用以下内容通过拖放操作发现电子邮件元数据.从Mail.app删除电子邮件(/线程).
Previously, I was using the following to discover e-mail meta-data from a drag & dropped e-mail(/-thread) from Mail.app.
if let filenames = draggingInfo.namesOfPromisedFilesDropped(atDestination: URL(fileURLWithPath: destinationDir!)) {
/// TODO: in future implementation Mail might return multiple filenames here.
/// So we will keep this structure to iterate the filenames
//var aPaths: [String] = []
//for _ in filenames {
if let aPath = pb.string(forType: "com.apple.pasteboard.promised-file-url") {
return aPath
}
//}
//return aPaths
}
有点笨拙，但它确实有效，因为仅在这种情况下提供了"com.apple.pasteboard.promised-file-url" .
Kind of janky, but it worked, since "com.apple.pasteboard.promised-file-url" was only supplied in those situations.
但是，自10.12开始，API似乎已更改，并查看 WWDC2016对话，似乎苹果公司希望我们现在使用NSFilePromiseReceiver.我尝试了几种方法，但无法弹出承诺的文件URL.
Since 10.12 however, the API seems to have changed, and looking at the WWDC2016 talk it appears that Apple wants us to use NSFilePromiseReceiver now. I've tried a couple of approaches but I can't get a promised file URL to pop out.
设置:
class DropzoneView: NSView {
var supportedDragTypes = [
kUTTypeURL as String, // For any URL'able types
"public.url-name", // E-mail title
"public.utf8-plain-text", // Plaintext item / E-mail thread title / calendar event date placeholder
"com.apple.pasteboard.promised-file-content-type", // Calendar event / Web URL / E-mail thread type detection
"com.apple.mail.PasteboardTypeMessageTransfer", // E-mail thread detection
"NSPromiseContentsPboardType", // E-mail thread meta-data
"com.apple.pasteboard.promised-file-url", // E-mail thread meta-data
"com.apple.NSFilePromiseItemMetaData" // E-mail thread meta-data
]
override func viewDidMoveToSuperview() {
var dragTypes = self.supportedDragTypes.map { (type) -> NSPasteboard.PasteboardType in
return NSPasteboard.PasteboardType(type)
} // Experiment:
dragTypes.append(NSPasteboard.PasteboardType.fileContentsType(forPathExtension: "eml"))
dragTypes.append(NSPasteboard.PasteboardType.fileContentsType(forPathExtension: "emlx"))
self.registerForDraggedTypes(dragTypes)
}
}
处理:
extension DropzoneView {
override func draggingEntered(_ sender: NSDraggingInfo) -> NSDragOperation {
return .copy
}
override func draggingUpdated(_ sender: NSDraggingInfo) -> NSDragOperation {
return .copy
}
override func performDragOperation(_ sender: NSDraggingInfo) -> Bool {
let pasteboard: NSPasteboard = sender.draggingPasteboard()
guard let filePromises = pasteboard.readObjects(forClasses: [NSFilePromiseReceiver.self], options: nil) as? [NSFilePromiseReceiver] else {
return false
}
var files = [Any]()
var errors = [Error]()
let filePromiseGroup = DispatchGroup()
let operationQueue = OperationQueue()
let newTempDirectoryURL = URL(fileURLWithPath: (NSTemporaryDirectory() + (UUID().uuidString) + "/"), isDirectory: true)
do {
try FileManager.default.createDirectory(at: newTempDirectoryURL, withIntermediateDirectories: true, attributes: nil)
}
catch {
return false
}
// Async attempt, either times out after a minute or so (Error Domain=NSURLErrorDomain Code=-1001 "(null)") or gives 'operation cancelled' error
filePromises.forEach({ filePromiseReceiver in
filePromiseGroup.enter()
filePromiseReceiver.receivePromisedFiles(atDestination: newTempDirectoryURL,
options: [:],
operationQueue: operationQueue,
reader: { (url, error) in
Swift.print(url)
if let error = error {
errors.append(error)
}
else if url.isFileURL {
files.append(url)
}
else {
Swift.print("No loadable URLs found")
}
filePromiseGroup.leave()
})
})
filePromiseGroup.notify(queue: DispatchQueue.main,
execute: {
// All done, check your files and errors array
Swift.print("URLs: \(files)")
Swift.print("errors: \(errors)")
})
Swift.print("URLs: \(files)")
return true
}
其他尝试:
// returns nothing
if let filenames = pasteboard.propertyList(forType: NSPasteboard.PasteboardType(rawValue: "com.apple.pasteboard.promised-file-url")) as? NSArray {
Swift.print(filenames)
}
// doesn't result in usable URLs either
if let urls = pasteboard.readObjects(forClasses: [NSPasteboardItem.self /*NSURL.self, ???*/], options: [:]) as? [...
任何指针将不胜感激.
推荐答案
在尝试将承诺的文件接收到无效的目标URL时，我看到了此错误.
I saw this error when trying to receive promised files to an invalid destination url.
就我而言，我使用的是 Ole Begemann的临时文件助手并意外地使其超出范围，这会在复制任何内容之前删除该目录.
In my case I was using Ole Begemann's Temporary File Helper and accidentally letting it go out of scope, which deleted the directory before anything could be copied.
receivePromisedFiles 在漫长的等待后给了我-1001超时错误，但是它仍然传递了将正确输入的URL.显然，该位置没有文件.
receivePromisedFiles gave me the -1001 timeout error after a long wait, but it did still pass a URL that would have been correct given my inputs. Obviously no file was at that location.
当我更改为有效的URL时，所有功能均按预期工作.可能值得检查沙箱问题等.
When I changed to a valid url all worked as expected. It might be worth checking Sandbox issues etc.
Apple现在在此处的文件承诺"部分中提供了一些有用的示例项目: https://developer.apple.com/documentation/appkit/documents_data_and_pasteboard
Apple now have some useful example projects in the File Promises section here: https://developer.apple.com/documentation/appkit/documents_data_and_pasteboard
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