I've written an application that downloads images from a website.
If this image already exists on the device I'm trying to replace it.
func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {
let userId = Int.init(downloadTask.taskDescription!)! // task description is definetly set in downloadImage() and is an Int
guard let target = imageFolder?.appendingPathComponent("\(userId).jpg") else {
delegate?.imageDownloadFailed(forUser: userId, error: "Could not create target URL.")
return
}
do {
if fileManager.fileExists(atPath: target.path) {
_ = try fileManager.replaceItemAt(target, withItemAt: location)
} else {
try fileManager.moveItem(at: location, to: target)
}
delegate?.savedImage(forUser: userId, at: target)
} catch let error {
delegate?.imageDownloadFailed(forUser: userId, error: error.localizedDescription)
}
}
The problem occurs in the if-statement:
_ = try fileManager.replaceItemAt(target, withItemAt: location)
I always got EXC_BAD_ACCESS and I can't find the error.
fileManager, target, and location are non-nil.
I've already tried to dispatch the code synchronous to the main thread, but the error still persists.
Any advices?
Edit:
Since I'm not the only one who got this error I decided to create a bug report at Apple.
The report is available at Open Radar; click
I've also uploaded a playground file at pastebin.com which demonstrates the error and provides a quick solution similar to the one of naudec.
Had the same issue. Ended up writing my own version:
let fileManager = FileManager.default
func copyItem(at srcURL: URL, to dstURL: URL) {
do {
try fileManager.copyItem(at: srcURL, to: dstURL)
} catch let error as NSError {
if error.code == NSFileWriteFileExistsError {
print("File exists. Trying to replace")
replaceItem(at: dstURL, with: srcURL)
}
}
}
func replaceItem(at dstURL: URL, with srcURL: URL) {
do {
try fileManager.removeItem(at: dstURL)
copyItem(at: srcURL, to: dstURL)
} catch let error as NSError {
print(error.localizedDescription)
}
}
I call copyItem first.
The class holding this method does not exist any more at the time your download finishes and did release your filemanager. Create the FileManager within your completion closure:
...
let localFilemanager = FileManager.default
do {
...
Related
I was doing download system with the code from https://stackoverflow.com/a/32322851/7789222. It was a great and complete code but I can find a way to pass foldername from view controller to download file to specific folder. Can anyone help me with it please. I am using swift 3 xcode 8.
If I hard code the custom directory in func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) , every file will be downloaded to same folder. I want to pass the foldername from view controller so I can download files to different folder. I cant hardcode because I retrieve file name and foldername from server
The destination URL in the example is given by
let destinationURL = try manager.url(
for: .documentDirectory,
in: .userDomainMask,
appropriateFor: nil,
create: false
).appendingPathComponent(url.lastPathComponent)
(Line 17)
You can just pass a destination folder URL to the initializer of DownloadOperation which replaces the destination URL in the example:
let destinationURL = yourDestinationFolder.appendingPathComponent(url.lastPathComponent)
Your modified DownloadOperation would look something like this:
class DownloadOperation : AsynchronousOperation {
var task: URLSessionTask!
let destinationFolder: URL
init(session: URLSession, url: URL, destinationFolder: URL) {
super.init()
self.destinationFolder = destinationFolder
task = session.downloadTask(with: url) { temporaryURL, response, error in
defer { self.completeOperation() }
guard error == nil && temporaryURL != nil else {
print("\(error)")
return
}
do {
let manager = FileManager.default
let destinationURL = destinationFolder.appendingPathComponent(url.lastPathComponent)
_ = try? manager.removeItem(at: destinationURL) // remove the old one, if any
try manager.moveItem(at: temporaryURL!, to: destinationURL) // move new one there
} catch let moveError {
print("\(moveError)")
}
}
}
...
}
The code for adding operations is then
queue.addOperation(DownloadOperation(session: session, url: url, destinationFolder: destinationFolder))
If you want to use the DownloadManager:
class DownloadManager {
#discardableResult
func addDownload(_ url: URL, to destinationFolder: URL) -> DownloadOperation {
let operation = DownloadOperation(session: session, url: url, destinationFolder: destinationFolder)
operations[operation.task.taskIdentifier] = operation
queue.addOperation(operation)
return operation
}
...
}
The extension:
extension DownloadOperation: URLSessionDownloadDelegate {
func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {
do {
let manager = FileManager.default
let destinationURL = destinationFolder.appendingPathComponent(downloadTask.originalRequest!.url!.lastPathComponent)
if manager.fileExists(atPath: destinationURL.path) {
try manager.removeItem(at: destinationURL)
}
try manager.moveItem(at: location, to: destinationURL)
} catch {
print("\(error)")
}
}
...
}
Then you can add downloads with
downloadManager.addDownload(url, to: destinationFolder)
I do have a UIWebView included where a public URL is loaded; unfortunately, vcard and ical-Links are not handled, i.e. nothing happens when I click on them.
I tried to set all data detectors, no luck unfortunately.
In the Xcode-log, I get this here when clicking on such a link:
2017-07-14 13:43:00.982413+0200 xxx[2208:967973] WF: _userSettingsForUser mobile: {
filterBlacklist = (
);
filterWhitelist = (
);
restrictWeb = 1;
useContentFilter = 0;
useContentFilterOverrides = 0;
whitelistEnabled = 0;
}
In Safari, the same stuff works as expected.
If I use UIApplication.shared.openURL(icsOrVcardUrl) Safari gets opened and from there everything works as expected again, but I don't want the user to leave the app...
EDIT
This doesn't work either:
func webView(_ webView: UIWebView, shouldStartLoadWith request: URLRequest, navigationType: UIWebViewNavigationType) -> Bool {
if let url = request.url {
if url.absoluteString.contains("=vcard&") || url.absoluteString.contains("/ical/") {
let sessionConfig = URLSessionConfiguration.default
let session = URLSession(configuration: sessionConfig)
let request = URLRequest(url:url)
let task = session.downloadTask(with: request) { (tempLocalUrl, response, error) in
if let tempLocalUrl = tempLocalUrl, error == nil {
DispatchQueue.main.async {
self.documentController.url = tempLocalUrl
self.documentController.presentPreview(animated: true)
}
}
}
task.resume()
return false
}
}
return true
}
Use a UIDocumentInteractionController to preview without leaving your app.
I tested it quickly with an .ics file and it works fine.
Implement the UIDocumentInteractionControllerDelegate protocol
extension MainViewController: UIDocumentInteractionControllerDelegate {
func documentInteractionControllerViewControllerForPreview(_ controller: UIDocumentInteractionController) -> UIViewController {
return self;
}
}
Create an instance of the interaction controller:
let documentController = UIDocumentInteractionController()
Intercept the clicks in your UIWebView in shouldStartLoadWithRequest, return false for links you want to handle with the in-app preview and true for all the rest. And finally:
func previewDocument(_ url: URL) {
documentController.url = url
documentController.presentPreview(animated: true)
}
Here it is in the simulator
EDIT:
In response to the comment to this answer:
The reason it doesn't work for you is because the UIDocumentInteractionController depends on the file extension. The extension of the temp file is .tmp
Renaming the file after the download solves the problem. Quick and dirty example:
let task = session.downloadTask(with: url!) { (tempLocalUrl, response, error) in
if let tempLocalUrl = tempLocalUrl, error == nil {
do {
let filemgr = FileManager.default
let newUrl = tempLocalUrl.appendingPathExtension("ics")
try filemgr.moveItem(at: tempLocalUrl, to: newUrl)
DispatchQueue.main.async {
self.documentController.url = newUrl
self.documentController.presentPreview(animated: true)
}
} catch let error {
print("Error!!!: \(error.localizedDescription)")
}
}
}
task.resume()
In this case it is advisable to clean after yourself, because the file won't be deleted after the task completes although the OS will delete it eventually, when space is needed. If you often access the same urls, Library/Caches/ may be a better place for this files, just come up with good naming schema, and check if the file doesn't exist already.
My project had been getting the URL string for the medium sized profile pic using this code:
let downloadMediumPicTask = session.dataTask(with: mediumProfPictureURL) { (data, response, error)
in
// The download has finished.
if let e2 = error {
print("Error downloading profile picture: \(e2)")
} else {
if let res2 = response as? HTTPURLResponse {
print("Downloaded medium profile picture with response code \(res2.statusCode)")
if let imageData2 = data {
mediumProfilePictureUIImageFile = UIImage(data: imageData2)!
print("mediumProfilePictureUIImageFile has now been defined as: \(mediumProfilePictureUIImageFile).")
} else {
print("Couldn't get image: Image is nil")
}
} else {
print("Couldn't get response code for some reason")
}
}
}
downloadMediumPicTask.resume()
It crashes here giving a 403 response code. The URL that is being referenced is an expired signature URL from Facebook. Firebase doesn't adjust to get the new appropriate URL, and it was from Firebase that I had been getting the URL. I can't figure out how to get it directly as tried below:
func getUrlOfMediumProfilePic(){
if (FBSDKAccessToken.current() != nil) {
let graphPathPart2 = "me/picture"
let paramsPart2 = ["type":"medium", "redirect":"false"]
let completionHandlerPart2 = { (connection: FBSDKGraphRequestConnection?, result: Any?, error: Error?) in
if let error = error {
print("Medium picture graph call contained an error: \(error.localizedDescription)")
return
} else {
guard connection != nil else {
print("getURLOfLargeProfilePic() function aborted bc connection failed.")
return
}
let results = result! as! NSDictionary
let dataDict = results["data"] as! NSDictionary
stringOfMediumProfilePicURLaka100x100 = dataDict["url"] as! String
print("medium picture graph call results define stringOfMediumProfilePicURLaka100x100 as: \(stringOfMediumProfilePicURLaka100x100)")
}
}
let graphRequest = FBSDKGraphRequest(graphPath: graphPathPart2, parameters: paramsPart2)!
graphRequest.start(completionHandler: completionHandlerPart2)
}else{
print("User not logged in when getURLOfMediumProfilePic() function was run.")
return
}
}
This code yields an error with code 8.
Have you tried this:
https://graph.facebook.com/{id}/picture?width=100&height=100
I don't know swift, so I can't help about syntax. I think you can make http request to url and get image.
Hope this help :)
I'm using the following code to upload data (image) so amazon s3
func uploadData(data: Data, fileExtension: String, completion: #escaping (_ success: Bool, _ filename: String, _ url: String) -> ()) {
if let documentsDirectoryPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first {
let userId = 1
let fileName = "\(userId)_\(self.randomString()).\(fileExtension)"
let url = NSURL(fileURLWithPath: "\(documentsDirectoryPath)/\(fileName)")
let networkURLString = "\(appDel.assetAddress)/\(fileName)"
do {
try data.write(to: url as URL, options: .atomic)
} catch {
print("S3 Upload Error")
completion(false, "", "")
}
let uploadRequest: AWSS3TransferManagerUploadRequest = AWSS3TransferManagerUploadRequest()
uploadRequest.bucket = appDel.S3BucketName
uploadRequest.key = fileName
uploadRequest.body = url as URL!
let transferManager = AWSS3TransferManager.default()
let task = transferManager?.upload(uploadRequest)
task?.continue({ (task) -> Any? in
let success = (task.error == nil) && (task.result != nil)
if(!success){
print("S3 Upload Error: \(task.error)")
completion(false, "", "")
} else {
completion(success, fileName, networkURLString)
}
return nil
})
} else {
completion(false, "", "")
}
}
The image gets uploaded successfully; however, after returning completion of success with the filename and the url string... at around the line where it returns nil, the app takes a long time in the background doing AWS cleanup and all of a sudden gives an exception.
I'm trying to push a controller to the navigation bar on completion and it goes through that code but does nothing... as it's doing things in the background... although the image was already uploaded.
Nothing descriptive when it crashes that could help us find the issue.. any ideas?
Edit: Stack trace
2017-02-09 15:37:06.453327 HighThere[2021:526754] *** Assertion failure in void _UIPerformResizeOfTextViewForTextContainer(NSLayoutManager *, UIView<NSTextContainerView> *, NSTextContainer *, NSUInteger)(), /BuildRoot/Library/Caches/com.apple.xbs/Sources/UIFoundation/UIFoundation-491.4/UIFoundation/TextSystem/NSLayoutManager_Private.m:1577
2017-02-09 15:37:06.462391 HighThere[2021:526754] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Only run on the main thread!'
*** First throw call stack:
(0x18d7e91b8 0x18c22055c 0x18d7e908c 0x18e2a1098 0x1935c33d4 0x1935c30b8 0x1935f2b90 0x1935f5ea8 0x19361a3a8 0x193619ab4 0x19374c8b8 0x19374c79c 0x1000e54d0 0x1000e0a98 0x1000e1390 0x1000e001c 0x1000e00f0 0x19369e924 0x1936b64b4 0x19383e5b4 0x193756e74 0x193756adc 0x193756a40 0x19369ba80 0x190b499d8 0x190b3e4cc 0x190b3e38c 0x190abb3e0 0x190ae2a68 0x190ae2f34 0x18c87bfbc 0x18c87bce4 0x18c87b378 0x18c87ad8c)
libc++abi.dylib: terminating with uncaught exception of type NSException
Great. I just needed to push the controller to the navigation controller on the main thread... brilliant. goodbye 2 hours
DispatchQueue.main.async(execute: {
self.navigationController?.pushViewController(vcIntro(), animated: true)
})
I'm hoping someone may be able to help me figure out a snafu I'm having with an app I am trying to write (or learn to write) in Swift 2.0. This previously worked in Swift 1.2, but after the necessary conversions, I am continunally facing the error;
Cannot invoke initializer of type 'NSData' with an argument list of type '(contenOfURL: NSURL, options: NSDataReadingOptions, error:nil)'
Here is my code, slightly truncated, that I am using;
...
class func fetchMinionData() -> [Minion] {
let myURL = "https://myurl/test.json"
let dataURL = NSURL(string: myURL)
let data = NSData(contentsOfURL: dataURL!, options: NSDataReadingOptions.DataReadingMappedIfSafe, error: nil)
//THIS IS THE LINE THAT THROWS THE ERROR
let minionJSON = JSON(data)
var minions = [Minion]()
for (_ , minionDictionary) in minionJSON {
minions.append(Minion(minionDetails: minionDictionary))
}
return minions
}
...
Note that I plan to use the SwiftyJSON library to further parse the data once it is downloaded. I am searching endlessly online, but I just can't seem to figure this out! Thank you!
If you are working with Swift 2, you should not pass the last argument "error". Instead put a try around the NSData initialization. If data needs to be accessed outside take the init result in a var and convert to let Modified code
var optData:NSData? = nil
do {
optData = try NSData(contentsOfURL: dataURL!, options: NSDataReadingOptions.DataReadingMappedIfSafe)
}
catch {
print("Handle \(error) here")
}
if let data = optData {
// Convert data to JSON here
}
Example code for Dictionary :) Swift 2.0
https://github.com/DaRkD0G/LoadExtension/edit/master/LoadExtensionDictionary.swift
enum EHError: ErrorType {
case Nil(String)
case NSData(String)
case JSON(String)
}
extension Dictionary {
/**
Loads a JSON file from the app bundle into a new dictionary
- parameter filename: File name
- throws: PathForResource / NSData / JSON
- returns: Dictionary<String, AnyObject>
*/
static func loadJSONFromBundle(filename: String) throws -> Dictionary<String, AnyObject> {
guard let path = NSBundle.mainBundle().pathForResource(filename, ofType: "json") else {
throw EHError.Nil("[EasyHelper][loadJSONFromBundle][->pathForResource] The file could not be located\nFile : '\(filename).json'")
}
guard let data = try? NSData(contentsOfFile: path, options:NSDataReadingOptions()) else {
throw EHError.NSData("[EasyHelper][loadJSONFromBundle][->NSData] The absolute path of the file not find\nFile : '\(filename)'")
}
guard let jsonDict = try NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions()) as? Dictionary<String, AnyObject> else {
throw EHError.JSON("[EasyHelper][loadJSONFromBundle][->NSJSONSerialization]Error.InvalidJSON Level file '\(filename)' is not valid JSON")
}
return jsonDict
}
}
If I do not do a mistake, for you is that
/**
Loads a JSON file from the app bundle into a new dictionary
- parameter filename: File name
- throws: EHError : PathForResource / NSData / JSON
- returns: [String : AnyObject]
*/
static func loadJSONFromBundle(filename: String, nameJson:String) throws -> [String : AnyObject] {
guard let path = NSBundle.mainBundle().pathForResource(filename, ofType: "json") else {
throw EHError.Nil("[EasyHelper][loadJSONFromBundle][->pathForResource] The file could not be located\nFile : '\(filename).json'")
}
guard let data = try? NSData(contentsOfFile: path, options:NSDataReadingOptions()) else {
throw EHError.NSData("[EasyHelper][loadJSONFromBundle][->NSData] The absolute path of the file not find\nFile : '\(filename)'")
}
guard let jsonDict = try NSJSONSerialization.JSONObjectWithData(data, options: .AllowFragments) as? [String : AnyObject] else {
throw EHError.JSON("[EasyHelper][loadJSONFromBundle][->NSJSONSerialization] Invalid JSON\n nameJson '\(nameJson)'\nFile '\(filename)'")
}
return jsonDict
}