I'm creating a Finder Share extension to be used when selecting a file. I'd like to show an image preview of the file that you are sharing (like you see in the Messages and Twitter Finder Share extensions, for example).
In the loadView method of the view controller for my share extension, I'm doing this:
let item = self.extensionContext!.inputItems[0] as! NSExtensionItem
if let attachments = item.attachments as? [NSItemProvider] {
if let attachment = attachments.first {
attachment.loadPreviewImage(options: nil, completionHandler: { (item, error) in
if error != nil {
//handle error...
} else if let img = item as? NSImage {
//put image preview in my "share sheet"...
}
})
}
}
The problem is that when I keep hitting the error condition. The error that I'm getting is:
Error Domain=NSItemProviderErrorDomain Code=-1000 "Cannot load preview." UserInfo={NSLocalizedDescription=Cannot load preview.}
For what it's worth, I am able to call attachment.loadItem() successfully and work with the file. But I don't really care to do anything with the file itself at this point, I just want a thumbnail image that represents the file which theoretically this method should give me...
Any ideas?
I am in the same situation. After read the manual, I think here is the reason.
"Loads the preview image for the item that is represented by the item provider."
However, it is not forced that the item provider must provides a preview. So the error simply says that there is no preview that the item provider can provide. You should do it yourself.
Related
UPDATE
I tried the following code solution and it allows for me to save to Google Drive now, but Egnyte and Dropbox are still greyed out.
func exportPhotosToFileLocation() {
var fileURLArray = [URL]()
for data in reviewDataController.tableViewReviewData {
guard let imageData = data.image.jpegData(compressionQuality: 1.00) else {
print("ERROR: Unable to print convert image to jpegData in exportPhotosToFileLocation!")
return
}
let fileManager = FileManager.default
do {
let fileURL = fileManager.temporaryDirectory.appendingPathComponent("\(data.imageTitle)").appendingPathExtension("jpeg")
try imageData.write(to: fileURL)
fileURLArray.append(fileURL)
print("Successfully created file from jpegData in exportPhotosToFileLocation!")
} catch {
print("ERROR: Unable to create file from jpegData in exportPhotosToFileLocation!")
return
}
}
if #available(iOS 14, *) {
let controller = UIDocumentPickerViewController(forExporting: fileURLArray)
present(controller, animated: true)
}
else {
let controller = UIDocumentPickerViewController(urls: fileURLArray, in: .exportToService)
present(controller, animated: true)
}
}
Here is the developer documents for Egnyte. Unfortunately, none of it makes sense to me as a beginner.
Egnyte Developer Documentation
----------------------------------------------------------------------------------------------
ORIGINAL POST
In my app, I'm trying to allow the user to select a save location (so choose a folder). Whenever I use this code, Egnyte/Google Drive/Dropbox are all "greyed" out and inaccessible.
let supportedTypes : [UTType] = [UTType.folder]
let documentPickerController = UIDocumentPickerViewController(forOpeningContentTypes: supportedTypes)
documentPickerController.delegate = self
self.present(documentPickerController, animated: true, completion: nil)
If I change supportedTypes to
let supportedTypes : [UTType] = [UTType.text]
It does let me access them. Does anyone have a solution for this? I obviously need the user to be able to select a folder in these applications... you can see why that is important.
This is up to the file provider extension (Google Drive, etc.). To allow picking a folder, the file provider has to lay content in its directory in a hierarchical manner... if they do this, they need to specify NSExtensionFileProviderSupportsPickingFolders in their Info.plist to tell the system it's allowed to choose folders.
Do you need to choose a save location and persist it? If yes, then you'll be blocked on the file provider implementing the necessary API. If not, the type you pass should the type of the document you are actually saving. The document will be saved once in the chosen folder (without any additional requirements on the file provider extension), and you will have to use the document picker again to save the next document.
If you are trying to select Dropbox as a location to import files from in the Apple File Importer but it does not advance to the file selection screen I found that restarting my iPhone seemed to resolve that issue.
I wanna drag files to my window and then perform actions.
I tried to use snippets below provided in this answer to distinguish whether you're dragging a file or a window.
// In my window controller
class MyWindowController: NSWindowController {
init() {
// Some initialization steps below are omitted
let win = NSWindow(...)
super.init(window: win)
let contentView = DropView(frame: win.frame)
win.contentView?.addSubview(contentView)
registerGlobalMouseEvent()
}
func registerGlobalMouseEvent() {
self.window?.acceptsMouseMovedEvents = true
NSEvent.addGlobalMonitorForEvents(matching: .leftMouseDragged, handler: { [self] event in
// Codes below will cause errors
let pasteBoard = NSPasteboard(name: .drag)
guard let fileNames = pasteBoard.propertyList(forType: .init(rawValue: "NSFilenamesPboardType")) as? NSArray else { return }
let changeCount = pasteBoard.changeCount
if fileNames.count > 0 && lastChangeCount != changeCount {
lastChangeCount = changeCount
// My actions when dragging
}
})
}
}
Then I ran my codes and started dragging, I got three errors:
[sandbox] Failed to get a sandbox extension
[Framework] Failed to issue sandbox extension for /Users/roy/Downloads/test.txt with error 1
[default] Failed to issue sandbox token for URL: 'file:///Users/roy/Downloads/test.txt' with error: 'Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted" UserInfo={NSLocalizedDescription=Cannot issue a sandbox extension for file "/Users/roy/Downloads/test.txt": Operation not permitted}'
But when I just do
NSEvent.addGlobalMonitorForEvents(matching: .leftMouseDragged, handler: { [self] event in
// My actions
})
, then everything went fine.
The first error seems harmless since it didn't prevent my app from running.
The second and the third ones are deadly and directly caused my app to crash.
I wonder if there are any problems in his code? Any useful thoughts would be great! :)
You need to know about Bookmarks and Security Scoped URLs when working with sandbox . A dragged URL gives your app process permission just once to read or read/write a “user selected file” depending on how you configure entitlements.
You can save a bookmark (blob of data) to keep access over subsequent sessions as long as the file isn’t updated by another process at which point the bookmark becomes stale and you will need to encourage the user to select the file again.
Handing a URL to another process across an XPC boundary like sharing requires that you own the file so may involve a copy to your sandbox cache.
e.g:
let dragurl = url_of_dragged_file //at this point you have at-least read access
let cachepath = NSSearchPathForDirectoriesInDomains(.cachesDirectory, .userDomainMask, true).last!
let cachedir = URL(fileURLWithPath: cachepath)
let cacheurl = cachedir
.appendingPathComponent(UUID().uuidString)
.appendingPathExtension(dragurl.pathExtension)
try FileManager.default.copyItem(at: dragurl, to: cacheurl)
At this point you have a copy in your local sandbox cache that can be handed off to a share sheet.
So I finally got a solution for this. :)
It appears that it indeed have something to do with the snippets I mentioned above, and here's the correction:
NSEvent.addGlobalMonitorForEvents(matching: .leftMouseDragged, handler: { [self] event in
let pasteboard = NSPasteboard(name: .drag)
let changeCount = pasteboard.changeCount
if lastChangeCount != changeCount {
lastChangeCount = changeCount
if pasteboard.canReadObject(forClasses: [NSURL.self], options: [:]) {
/// actions
}
}
})
In this way, I got no errors and my codes run perfectly!
Following this topic : iOS PDFkit cannot add custom attribute to pdf document
My app is using PDFKit to save files
I'm trying to set custom key metadata to PDFDocument I save on the device.
The object in my app ('Test') has two important properties :
id: a UUID to be able to retrieve the file on disk (the linked file on disk URL is this_UUID.jpg).
name: a human-readable string set by the user.
This cause some problems :
the file name is a UUID not human readable, so it's bad user experience.
If the user renames the file, the app won't be able to get the file.
So the id is to have a human-readable label for the file. So when the user opens the File app he can find it easily. And add metadata with the id so my app can retrieve it even if renamed. Looks like a nice solution right?
// First I create my own attribute
fileprivate extension PDFDocumentAttribute {
static let testId = PDFDocumentAttribute(rawValue: "com.sc.testID")
}
// Then I set the news attributes before saving the file, in the 'test' class
func setDocument(pdf: PDFDocument) {
let fileURL = self.getPDFDocumentURL()
print("the metadata is \(pdf.documentAttributes)") // print an empty dictionary
pdf.documentAttributes?[PDFDocumentAttribute.testId] = self.id
pdf.documentAttributes?[PDFDocumentAttribute.titleAttribute] = self.name // I suppose the ddisplay name of the document ? It's not, so what is that ?
print("the metadata is now \(pdf.documentAttributes)") // both are printed, it looks ok
//pdf.write(to: fileURL) // I tested this one too, same issues
let data = pdf.dataRepresentation()
do {
try data?.write(to: fileURL, options: .completeFileProtection)
} catch {
print(error.localizedDescription)
}
}
From here it looks ok, when I want to retrieve the pdf document I will check in the folder the id of each doc and return the doc when id match. But the problem is when I get the documentAttributes the attribute 'testId' isn't in. Note the native title, is set correctly.
So I could get the id from there but that looks pretty inappropriate
//still in 'Test' class
func getPDFDocument() -> PDFDocument? {
// get all docs in the folder ad check metadata for each
let fileManager = FileManager.default
let documentsURL = fileManager.urls(for: .documentDirectory, in: .userDomainMask)[0]
do {
let fileURLs = try fileManager.contentsOfDirectory(at: SchoolTest.getSubjectFolderURL(subject: self.subject!), includingPropertiesForKeys: nil)
for url in fileURLs {
print("the doc attributes are : \(PDFDocument(url: url)?.documentAttributes)") // contain title and others preset by Apple but not my custom 'testId'
if let doc = PDFDocument(url: url), doc.documentAttributes?[PDFDocumentAttribute.titleAttribute/*testId*/] as? String == self.documentName {
return doc // this work temporary
}
}
} catch {
print("Error while enumerating files \(documentsURL.path): \(error.localizedDescription)")
}
return nil
}
Display name:
Currently, the display name/label displayed in the File app is the file name (from URL).
This can cause problems too because if two 'Test' have the same name, their linked file gonna have the same URL. So when the most recent one will be saved on disk it will overwrite the other.
That's a problem I don't have when using the 'Test' id property for the file URL.
If I could set a display name for the file and keep the URL with the UUID that should resolve the problem.
Directories have the same localizing issue, I have named them with English but Apple native directories are localized. A localized name could be nice for user experience.
After hours of research, I can't find a way to localize or apply a display name to my files/directories.
// I tried that without positive result
var url = fileURL as NSURL
try url.setResourceValue("localized label", forKey: .localizedLabelKey)
print("localized name is \(try url.resourceValues(forKeys: [.localizedLabelKey]))")
let newURL = url as URL
try data?.write(to: newURL, options: .completeFileProtection)
Am I doing something badly? How should we do when adding custom metada to a file?
EDIT: Additional information added at the bottom
I have a sandboxed, document based application that loads a user selected quicktime movie into an AVPlayer, and everything was working perfectly.
Now I am upgrading the code so that it will use Security Scoped bookmarks to get the URL rather than just storing a URL string so that the persistent store will allow the movie to be loaded upon relaunch of the application. When the bookmark is created it is stored in a Data variable of a managed object.
For some reason, this has broken the AVPlayer. While I have created a bookmark from the user selected URL, and can resolving the URL from the bookmark when the application is relaunched, the movie is not getting loaded into the AVPlayer correctly and I can't figure out why... I have confirmed that the URL being resolved from the bookmark does point to the movie file.
I have also added the appropriate entitlements to the project.
Here is my code:
Function Where User Selects a Movie To Load and Bookmark is Created
#IBAction func loadMovie(_ sender: Any) {
let openPanel = NSOpenPanel()
openPanel.title = "Select Video File To Import"
openPanel.allowedFileTypes = ["mov", "avi", "mp4"]
openPanel.begin { (result: NSApplication.ModalResponse) -> Void in
if result == NSApplication.ModalResponse.OK {
self.movieURL = openPanel.url
self.player = AVPlayer.init(url: self.movieURL!)
self.setupMovie()
if self.loadedMovieDatabase.count > 0 {
print("Movie Object Exists. Adding URL String")
self.loadedMovieDatabase[0].urlString = String(describing: self.movieURL!)
} else {
print("No Movie Object Exists Yet. Creating one and adding URL String")
let document = NSDocumentController.shared.currentDocument as! NSPersistentDocument
let myManagedObjectContext = document.managedObjectContext!
let newMovie = NSEntityDescription.insertNewObject(forEntityName: "Movie", into: myManagedObjectContext) as! MovieMO
self.loadedMovieDatabase.append(newMovie)
self.loadedMovieDatabase[0].urlString = String(describing: self.movieURL!)
}
// create Security-Scoped bookmark - Added 2/1/18
do {
try self.loadedMovieDatabase[0].bookmark = (self.movieURL?.bookmarkData(options: NSURL.BookmarkCreationOptions.withSecurityScope, includingResourceValuesForKeys: nil, relativeTo: nil))!
} catch {
print("Can't create security bookmark!")
}
}
}
}
Function where Bookmark is Resolved into URL and Movie is Loaded
// initialize AVPlayer with URL stored in coreData movie object if it exists and is a valid path
if loadedMovieDatabase.count > 0 {
// initialize with saved movie path if it is valid (from security bookmark data)
// let myURL = URL(string: loadedMovieDatabase[0].urlString!) <- replaced with new code below
print("Loading URL from Bookmark")
var urlResult = false
var myURL : URL
do {
try myURL = URL.init(resolvingBookmarkData: loadedMovieDatabase[0].bookmark, bookmarkDataIsStale: &urlResult)!
print("URL Loaded from Bookmark")
print("URL is", myURL)
let isSecuredURL = myURL.startAccessingSecurityScopedResource()
print("IsSecured = ", isSecuredURL)
player = AVPlayer.init(url: myURL)
print("Setting Up Movie")
setupMovie()
} catch {
// No Data in bookmark so load default ColorBars movie instead
print("No Security Bookmark Available. Reverting to Default Color Bars")
let myURL = URL(string: initialMoviePath)
player = AVPlayer.init(url: myURL!)
setupMovie()
}
} else {
// load default ColorBars movie instead
print("Nothing was loaded so just set up a new document.")
let myURL = URL(string: initialMoviePath)
player = AVPlayer.init(url: myURL!)
setupMovie()
}
I am new to Security-Scoped Bookmarks, so I'm hoping that this may be obvious to anyone who has worked with them before.
I'm wondering if it's a problem with:
let isSecuredURL = myURL.startAccessingSecurityScopedResource()
Perhaps I'm calling this incorrectly? Sometimes I find Apple's documentation to be vague and confusing... Any insight would be appreciated!
EDIT:
I believe I know why this is happening, but I'm not sure how to fix it...
myURL.startAccessingSecurityScopedResource()
always returns FALSE... per the documentation that would mean that it's not working. Additionally, while the movie file is located on my Desktop, the Resolved URL comes up as the following (this may be normal, I don't know.):
file:///Users/me/Library/Containers/myapp/Data/Desktop/sample_on_desktop.mov
The apple docs make reference to the fact that a Document Scope can not use files in the system (aka "/Library"), but my entitlements are setup to use application-scope bookmarks, and my bookmark was created using the nil flag for relativeURL: so this shouldn't be an issue.
I just stumbled upon the answer accidentally...
For starters, when I was resolving the URL, I was not using the method which allows you to include OPTIONS, so my URL was resolved WITHOUT the security-scope. My original code to resolve was:
try myURL = URL.init(resolvingBookmarkData: loadedMovieDatabase[0].bookmark, bookmarkDataIsStable: &urlResult)!
When I should have been using the version with options here:
try myURL = URL.init(resolvingBookmarkData: loadedMovieDatabase[0].bookmark, Options: URL.bookmarkResolutionOptions.withSecurityScope, relativeTo: nil, bookmarkDataIsStable: &urlResult)!
Basically, I used the first init option Xcode presented in the predictive list with the words "resolvingBookmarkData:" when I should have looked further down the list. (This is how I found my error.)
NOTE also that it's important to use...
URL.bookmarkResolutionOptions.withSecurityScope
and not
URL.bookmarkCreationOptions.withSecurityScope
...when you're resolving your URL or it doesn't appear to work correctly.
Thus ends my frustration with this problem :) I hope this explanation might help others facing this problem!
I have a desktop app that receives e-mail URLs ("message://" scheme) from the drag&drop pasteboard and I want to get the Subject from the relevant message. The only clue I have, so far, is that the QuickLook library might give me an information object where I can retrieve this info from.
Since the QuickLook API seems to be rather in flux at the moment and most examples show how to use it in iOS, I simply cannot find a way to set up my "Preview" object using a URL and get the information from there.
I would like to avoid setting up my project as a QuickLook plugin, or setting up the whole preview pane / view scaffolding; at the moment I just want to get out what QuickLook loads before it starts displaying, but I can't comprehend what paradigm Apple wants me to implement here.
XCode 7.3.1.
It turns out I misinterpreted the contents of draggingInfo.draggingPasteboard().types as a hierarchical list containing only one type of info (URL in this case).
Had to subscribe to dragged event type kUTTypeMessage as String and retrieve the e-mail subject from the pasteboard with stringForType("public.url-name")
EDIT: Note that the current Mail.app will sometimes create a stack of mails when you drag an e-mail thread. Although the method above still works to get the subject of the stack, there is no URL in the dragging info then and since there's no list of Message-IDs available either, I had to resort to scraping the user's mbox directory:
// See if we can resolve e-mail message meta data
if let mboxPath = pboard.stringForType("com.apple.mail.PasteboardTypeMessageTransfer") {
if let automatorPlist = pboard.propertyListForType("com.apple.mail.PasteboardTypeAutomator") {
// Get the latest e-mail in the thread
if let maxID = (automatorPlist.allObjects.flatMap({ $0["id"]! }) as AnyObject).valueForKeyPath("#max.self") as? Int {
// Read its meta data in the background
let emailItem = draggingEmailItem
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) {
// Find the e-mail file
if let path = Util.findEmlById(searchPath: mboxPath, id: maxID) {
// Read its contents
emailItem.properties = Util.metaDataFromEml(path)
dispatch_async(dispatch_get_main_queue(), {
// Update UI
});
}
}
}
}
}
Util funcs:
/* Searches the given path for <id>.eml[x] and returns its URL if found
*/
static func findEmlById(searchPath searchPath: String, id: Int)-> NSURL? {
let enumerator = NSFileManager.defaultManager().enumeratorAtPath(searchPath)
while let element = enumerator?.nextObject() as? NSString {
switch (element.lastPathComponent, element.pathExtension) {
case (let lpc, "emlx") where lpc.hasPrefix("\(id)"):
return NSURL(fileURLWithPath: searchPath).URLByAppendingPathComponent(element as String)!
case (let lpc, "eml") where lpc.hasPrefix("\(id)"):
return NSURL(fileURLWithPath: searchPath).URLByAppendingPathComponent(element as String)!
default: ()
}
}
return nil
}
/* Reads an eml[x] file and parses it, looking for e-mail meta data
*/
static func metaDataFromEml(path: NSURL)-> Dictionary<String, AnyObject> {
// TODO Support more fields
var properties: Dictionary<String, AnyObject> = [:]
do {
let emlxContent = try String(contentsOfURL: path, encoding: NSUTF8StringEncoding)
// Parse message ID from "...\nMessage-ID: <...>"
let messageIdStrMatches = emlxContent.regexMatches("[\\n\\r].*Message-ID:\\s*<([^\n\r]*)>")
if !messageIdStrMatches.isEmpty {
properties["messageId"] = messageIdStrMatches[0] as String
}
}
catch {
print("ERROR: Failed to open emlx file")
}
return properties
}
Note: If your app is sandboxed you will need the com.apple.security.temporary-exception.files.home-relative-path.read-only entitlement set to an array with one string in it: /Library/