UIDocumentInteractionController file attachment error - swift

so I'm working on exporting a .txt file from Xcode, but whenever I try to export it, say through email, it creates an email with no attachments and an empty message. When I try to export it to iCloud Drive, a white screen comes up for a second, then leaves. When I check iCloud Drive, the file isn't there. What is wrong here?
let message = testLabel.text
func getDocumentsDirectory() -> NSString {
let paths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
let documentsDirectory = paths[0]
return documentsDirectory as NSString
}
let filePath = getDocumentsDirectory().appendingPathComponent("matrixFile.txt")
do{
try message?.write(toFile: filePath, atomically: true, encoding: String.Encoding.utf8)
}catch let error as NSError{
testLabel.text = String(describing: error)
}
let documentInteractionController = UIDocumentInteractionController()
documentInteractionController.url = NSURL.fileURL(withPath: filePath)
documentInteractionController.uti = "public.data, public.content"
documentInteractionController.name = "matrixFile"
documentInteractionController.presentOptionsMenu(from: view.frame, in: view, animated: true)


The problem is you are declaring your document interaction controller as a constant within the method that calls it, like:
func someButton() {
let controller = UIDocumentInteractionController...
}
It will not work like that. The interaction controller needs to be an instance variable of the class that presents it, and it should be reinitialized every time you present it with a new url, like so:
var controller: UIDocumentInteractionController!
func someButton() {
controller = UIDocumentInteractionController(url: someURL)
controller.presentOptionsMenu...
}
Why? I have no idea, but file a bug report if you think this is absurd.


Your UTI is wrong. For a text file you should use "public.text". But there is a constant for this already - kUTTypePlainText. You just need to import MobileCoreServices to use it.
import MobileCoreServices
then:
documentInteractionController.uti = kUTTypePlainText as String
You should also use the proper initializer when creating the controller:
let documentInteractionController = UIDocumentInteractionController(url: URL(fileURLWithPath: filePath))
documentInteractionController.uti = kUTTypePlainText as String
documentInteractionController.name = "matrixFile"
documentInteractionController.presentOptionsMenu(from: view.frame, in: view, animated: true)
And I would only create and show the controller if the text isn't nil and you successfully write the file:
if let message = testLabel.text {
let filePath = getDocumentsDirectory().appendingPathComponent("matrixFile.txt")
do {
try message.write(toFile: filePath, atomically: true, encoding: String.Encoding.utf8)
let documentInteractionController = UIDocumentInteractionController(url: URL(fileURLWithPath: filePath))
documentInteractionController.uti = kUTTypePlainText as String
documentInteractionController.name = "matrixFile"
documentInteractionController.presentOptionsMenu(from: view.frame, in: view, animated: true)
} catch let error as NSError {
testLabel.text = String(describing: error)
}
}

Related

Swift : Trouble Exporting Database

I'm trying to Export my Database.
I've tried by Email and by sharing it.
The thing is that I want to export the current state of the dataBase (with all the information in it).
I've tried this code :
func exportDatabase(){
var url:String = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).last! as String
url = url + "/WalletDatabase.sqlite"
let fileManager = FileManager.default
if fileManager.fileExists(atPath: url) {
sendMail(sUrl: url)
}else{
print("error")
}
}
func sendMail(sUrl:String){
if( MFMailComposeViewController.canSendMail() ) {
print("Can send email.")
let fileManager = FileManager.default
let mailComposer = MFMailComposeViewController()
mailComposer.setToRecipients(["***#gmail.com"])
mailComposer.mailComposeDelegate = self
//Set the subject and message of the email
mailComposer.setSubject("Lorem Ipsum")
mailComposer.setMessageBody("Lorem Ipsum.", isHTML: false)
if let fileData = NSData(contentsOfFile: sUrl) {
print("File data loaded.")
mailComposer.addAttachmentData(fileData as Data, mimeType: "application/x-sqlite3", fileName: "WalletDatabase")
}
let fileData = fileManager.contents(atPath: sUrl)
} else {
print("error")
}
But :
The file send doesn't have any type
The database is empty, only the table and col remain
Could you guys give me a little help

I fix it by adding this following code :
static func migrateStoreSwift() -> NSURL
{
let lApp:AppController = UIApplication.shared.delegate as! AppController;
let lCurrentStore:NSPersistentStore = lApp.persistentStoreCoordinator.persistentStores.last!
let lNewDataBase = "Database.sqlite"
let lNewStoreURL:NSURL = lApp.applicationDocumentsDirectory()?.appendingPathComponent(lNewDataBase) as! NSURL
try! lApp.persistentStoreCoordinator.migratePersistentStore(lCurrentStore, to: lNewStoreURL as URL, options: nil, withType: NSSQLiteStoreType)
return lNewStoreURL
}
This code create a copy of the current version of the database.

How To Read From File Swift [duplicate]

I need to read and write data to/from a text file, but I haven't been able to figure out how.
I found this sample code in the Swift's iBook, but I still don't know how to write or read data.
import Cocoa
class DataImporter {
/*
DataImporter is a class to import data from an external file.
The class is assumed to take a non-trivial amount of time to initialize.
*/
var fileName = "data.txt"
// the DataImporter class would provide data importing functionality here
}
class DataManager {
#lazy var importer = DataImporter()
var data = String[]()
// the DataManager class would provide data management functionality here
}
let manager = DataManager()
manager.data += "Some data"
manager.data += "Some more data"
// the DataImporter instance for the importer property has not yet been created”
println(manager.importer.fileName)
// the DataImporter instance for the importer property has now been created
// prints "data.txt”
var str = "Hello World in Swift Language."

For reading and writing you should use a location that is writeable, for example documents directory. The following code shows how to read and write a simple string. You can test it on a playground.
Swift 3.x - 5.x
let file = "file.txt" //this is the file. we will write to and read from it
let text = "some text" //just a text
if let dir = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first {
let fileURL = dir.appendingPathComponent(file)
//writing
do {
try text.write(to: fileURL, atomically: false, encoding: .utf8)
}
catch {/* error handling here */}
//reading
do {
let text2 = try String(contentsOf: fileURL, encoding: .utf8)
}
catch {/* error handling here */}
}
Swift 2.2
let file = "file.txt" //this is the file. we will write to and read from it
let text = "some text" //just a text
if let dir = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.AllDomainsMask, true).first {
let path = NSURL(fileURLWithPath: dir).URLByAppendingPathComponent(file)
//writing
do {
try text.writeToURL(path, atomically: false, encoding: NSUTF8StringEncoding)
}
catch {/* error handling here */}
//reading
do {
let text2 = try NSString(contentsOfURL: path, encoding: NSUTF8StringEncoding)
}
catch {/* error handling here */}
}
Swift 1.x
let file = "file.txt"
if let dirs : [String] = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.AllDomainsMask, true) as? [String] {
let dir = dirs[0] //documents directory
let path = dir.stringByAppendingPathComponent(file);
let text = "some text"
//writing
text.writeToFile(path, atomically: false, encoding: NSUTF8StringEncoding, error: nil);
//reading
let text2 = String(contentsOfFile: path, encoding: NSUTF8StringEncoding, error: nil)
}

Assuming that you have moved your text file data.txt to your Xcode-project (Use drag'n'drop and check "Copy files if necessary") you can do the following just like in Objective-C:
let bundle = NSBundle.mainBundle()
let path = bundle.pathForResource("data", ofType: "txt")
let content = NSString.stringWithContentsOfFile(path) as String
println(content) // prints the content of data.txt
Update:
For reading a file from Bundle (iOS) you can use:
let path = NSBundle.mainBundle().pathForResource("FileName", ofType: "txt")
var text = String(contentsOfFile: path!, encoding: NSUTF8StringEncoding, error: nil)!
println(text)
Update for Swift 3:
let path = Bundle.main.path(forResource: "data", ofType: "txt") // file path for file "data.txt"
var text = String(contentsOfFile: path!, encoding: NSUTF8StringEncoding, error: nil)!
For Swift 5
let path = Bundle.main.path(forResource: "ListAlertJson", ofType: "txt") // file path for file "data.txt"
let string = try String(contentsOfFile: path!, encoding: String.Encoding.utf8)

Xcode 8.x • Swift 3.x or later
do {
// get the documents folder url
if let documentDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first {
// create the destination url for the text file to be saved
let fileURL = documentDirectory.appendingPathComponent("file.txt")
// define the string/text to be saved
let text = "Hello World !!!"
// writing to disk
// Note: if you set atomically to true it will overwrite the file if it exists without a warning
try text.write(to: fileURL, atomically: false, encoding: .utf8)
print("saving was successful")
// any posterior code goes here
// reading from disk
let savedText = try String(contentsOf: fileURL)
print("savedText:", savedText) // "Hello World !!!\n"
}
} catch {
print("error:", error)
}

New simpler and recommended method:
Apple recommends using URLs for filehandling and the other solutions here seem deprecated (see comments below).
The following is the new simple way of reading and writing with URL's:
Swift 5+, 4 and 3.1
import Foundation // Needed for those pasting into Playground
let fileName = "Test"
let dir = try? FileManager.default.url(for: .documentDirectory,
in: .userDomainMask, appropriateFor: nil, create: true)
guard let fileURL = dir?.appendingPathComponent(fileName).appendingPathExtension("txt") else {
fatalError("Not able to create URL")
}
// Writing to the file named Test
let outString = "Write this text to the file"
do {
try outString.write(to: fileURL, atomically: true, encoding: .utf8)
} catch {
assertionFailure("Failed writing to URL: \(fileURL), Error: " + error.localizedDescription)
}
// Reading it back from the file
var inString = ""
do {
inString = try String(contentsOf: fileURL)
} catch {
assertionFailure("Failed reading from URL: \(fileURL), Error: " + error.localizedDescription)
}
print("Read from the file: \(inString)")

Xcode 8, Swift 3 way to read file from the app bundle:
if let path = Bundle.main.path(forResource: filename, ofType: nil) {
do {
let text = try String(contentsOfFile: path, encoding: String.Encoding.utf8)
print(text)
} catch {
printError("Failed to read text from \(filename)")
}
} else {
printError("Failed to load file from app bundle \(filename)")
}
Here's a convenient copy and paste Extension
public extension String {
func contentsOrBlank()->String {
if let path = Bundle.main.path(forResource:self , ofType: nil) {
do {
let text = try String(contentsOfFile:path, encoding: String.Encoding.utf8)
return text
} catch { print("Failed to read text from bundle file \(self)") }
} else { print("Failed to load file from bundle \(self)") }
return ""
}
}
For example
let t = "yourFile.txt".contentsOrBlank()
You almost always want an array of lines:
let r:[String] = "yourFile.txt"
.contentsOrBlank()
.characters
.split(separator: "\n", omittingEmptySubsequences:ignore)
.map(String.init)

I want to show you only the first part, that is read. Here's how simply you can read:
Swift 3:
let s = try String(contentsOfFile: Bundle.main.path(forResource: "myFile", ofType: "txt")!)
Swift 2:
let s = try! String(contentsOfFile: NSBundle.mainBundle().pathForResource("myFile", ofType: "txt")!)

Simplest way to read a file in Swift > 4.0
let path = Bundle.main.path(forResource: "data", ofType: "txt") // file path for file "data.txt"
do {
var text = try String(contentsOfFile: path!)
}
catch(_){print("error")}
}

You may find this tool useful to not only read from file in Swift but also parse your input: https://github.com/shoumikhin/StreamScanner
Just specify the file path and data delimiters like this:
import StreamScanner
if let input = NSFileHandle(forReadingAtPath: "/file/path")
{
let scanner = StreamScanner(source: input, delimiters: NSCharacterSet(charactersInString: ":\n")) //separate data by colons and newlines
while let field: String = scanner.read()
{
//use field
}
}
Hope, this helps.

This works with Swift 3.1.1 on Linux:
import Foundation
let s = try! String(contentsOfFile: "yo", encoding: .utf8)

The current accepted answer above from Adam had some errors for me but here is how I reworked his answer and made this work for me.
let file = "file.txt"
let dirs: [String]? = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.AllDomainsMask, true) as? [String]
if (dirs != nil) {
let directories:[String] = dirs!
let dirs = directories[0]; //documents directory
let path = dirs.stringByAppendingPathComponent(file);
let text = "some text"
//writing
text.writeToFile(path, atomically: false, encoding: NSUTF8StringEncoding, error: nil);
//reading
var error:NSError?
//reading
let text2 = String(contentsOfFile: path, encoding:NSUTF8StringEncoding, error: &error)
if let theError = error {
print("\(theError.localizedDescription)")
}
}

To avoid confusion and add ease, I have created two functions for reading and writing strings to files in the documents directory. Here are the functions:
func writeToDocumentsFile(fileName:String,value:String) {
let documentsPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as! NSString
let path = documentsPath.stringByAppendingPathComponent(fileName)
var error:NSError?
value.writeToFile(path, atomically: true, encoding: NSUTF8StringEncoding, error: &error)
}
func readFromDocumentsFile(fileName:String) -> String {
let documentsPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as! NSString
let path = documentsPath.stringByAppendingPathComponent(fileName)
var checkValidation = NSFileManager.defaultManager()
var error:NSError?
var file:String
if checkValidation.fileExistsAtPath(path) {
file = NSString(contentsOfFile: path, encoding: NSUTF8StringEncoding, error: nil) as! String
} else {
file = "*ERROR* \(fileName) does not exist."
}
return file
}
Here is an example of their use:
writeToDocumentsFile("MyText.txt","Hello world!")
let value = readFromDocumentsFile("MyText.txt")
println(value) //Would output 'Hello world!'
let otherValue = readFromDocumentsFile("SomeText.txt")
println(otherValue) //Would output '*ERROR* SomeText.txt does not exist.'
Hope this helps!
Xcode Version: 6.3.2

I had to recode like this:
let path = NSBundle.mainBundle().pathForResource("Output_5", ofType: "xml")
let text = try? NSString(contentsOfFile: path! as String, encoding: NSUTF8StringEncoding)
print(text)

In the function example, (read|write)DocumentsFromFile(...) having some function wrappers certainly seems to makes sense since everything in OSx and iOS seems to need three or four major classes instantiated and a bunch of properties, configured, linked, instantiated, and set, just to write "Hi" to a file, in 182 countries.
However, these examples aren't complete enough to use in a real program. The write function does not report any errors creating or writing to the file. On the read, I don't think it's a good idea to return an error that the file doesn't exist as the string that is supposed to contain the data that was read. You would want to know that it failed and why, through some notification mechanism, like an exception. Then, you can write some code that outputs what the problem is and allows the user to correct it, or "correctly" breaks the program at that point.
You would not want to just return a string with an "Error file does not exist" in it. Then, you would have to look for the error in the string from calling function each time and handle it there. You also possibly couldn't really tell if the error string was actually read from an actual file, or if it was produced from your code.
You can't even call the read like this in swift 2.2 and Xcode 7.3 because NSString(contentsOfFile...) throws an exception. It is a compile time error if you do not have any code to catch it and do something with it, like print it to stdout, or better, an error popup window, or stderr. I have heard that Apple is moving away from try catch and exceptions, but it's going to be a long move and it's not possible to write code without this. I don't know where the &error argument comes from, perhaps an older version, but NSString.writeTo[File|URL] does not currently have an NSError argument. They are defined like this in NSString.h :
public func writeToURL(url: NSURL, atomically useAuxiliaryFile: Bool, encoding enc: UInt) throws
public func writeToFile(path: String, atomically useAuxiliaryFile: Bool, encoding enc: UInt) throws
public convenience init(contentsOfURL url: NSURL, encoding enc: UInt) throws
public convenience init(contentsOfFile path: String, encoding enc: UInt) throws
Also, the file not existing is just one of a number of potential problems your program might have reading a file, such as a permissions problem, the file size, or numerous other issues that you would not even want to try to code a handler for each one of them. It's best to just assume it's all correct and catch and print, or handle, an exception if something goes amiss, besides, at this point, you don't really have a choice anyway.
Here are my rewrites :
func writeToDocumentsFile(fileName:String,value:String) {
let documentsPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as NSString!
let path = documentsPath.stringByAppendingPathComponent(fileName)
do {
try value.writeToFile(path, atomically: true, encoding: NSUTF8StringEncoding)
} catch let error as NSError {
print("ERROR : writing to file \(path) : \(error.localizedDescription)")
}
}
func readFromDocumentsFile(fileName:String) -> String {
let documentsPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as NSString
let path = documentsPath.stringByAppendingPathComponent(fileName)
var readText : String = ""
do {
try readText = NSString(contentsOfFile: path, encoding: NSUTF8StringEncoding) as String
}
catch let error as NSError {
print("ERROR : reading from file \(fileName) : \(error.localizedDescription)")
}
return readText
}

For my txt file works this way:
let myFileURL = NSBundle.mainBundle().URLForResource("listacomuni", withExtension: "txt")!
let myText = try! String(contentsOfURL: myFileURL, encoding: NSISOLatin1StringEncoding)
print(String(myText))

Latest swift3 code
You can read data from text file just use bellow code
This my text file
{
"NumberOfSlices": "8",
"NrScenes": "5",
"Scenes": [{
"dataType": "label1",
"image":"http://is3.mzstatic.com/image/thumb/Purple19/v4/6e/81/31/6e8131cf-2092-3cd3-534c-28e129897ca9/mzl.syvaewyp.png/53x53bb-85.png",
"value": "Hello",
"color": "(UIColor.red)"
}, {
"dataType": "label2",
"image":"http://is1.mzstatic.com/image/thumb/Purple71/v4/6c/4c/c1/6c4cc1bc-8f94-7b13-f3aa-84c41443caf3/mzl.hcqvmrix.png/53x53bb-85.png",
"value": "Hi There",
"color": "(UIColor.blue)"
}, {
"dataType": "label3",
"image":"http://is1.mzstatic.com/image/thumb/Purple71/v4/6c/4c/c1/6c4cc1bc-8f94-7b13-f3aa-84c41443caf3/mzl.hcqvmrix.png/53x53bb-85.png",
"value": "hi how r u ",
"color": "(UIColor.green)"
}, {
"dataType": "label4",
"image":"http://is1.mzstatic.com/image/thumb/Purple71/v4/6c/4c/c1/6c4cc1bc-8f94-7b13-f3aa-84c41443caf3/mzl.hcqvmrix.png/53x53bb-85.png",
"value": "what are u doing ",
"color": "(UIColor.purple)"
}, {
"dataType": "label5",
"image":"http://is1.mzstatic.com/image/thumb/Purple71/v4/6c/4c/c1/6c4cc1bc-8f94-7b13-f3aa-84c41443caf3/mzl.hcqvmrix.png/53x53bb-85.png",
"value": "how many times ",
"color": "(UIColor.white)"
}, {
"dataType": "label6",
"image":"http://is1.mzstatic.com/image/thumb/Purple71/v4/5a/f3/06/5af306b0-7cac-1808-f440-bab7a0d18ec0/mzl.towjvmpm.png/53x53bb-85.png",
"value": "hi how r u ",
"color": "(UIColor.blue)"
}, {
"dataType": "label7",
"image":"http://is5.mzstatic.com/image/thumb/Purple71/v4/a8/dc/eb/a8dceb29-6daf-ca0f-d037-df9f34cdc476/mzl.ukhhsxik.png/53x53bb-85.png",
"value": "hi how r u ",
"color": "(UIColor.gry)"
}, {
"dataType": "label8",
"image":"http://is2.mzstatic.com/image/thumb/Purple71/v4/15/23/e0/1523e03c-fff2-291e-80a7-73f35d45c7e5/mzl.zejcvahm.png/53x53bb-85.png",
"value": "hi how r u ",
"color": "(UIColor.brown)"
}]
}
You can use this code you get data from text json file in swift3
let filePath = Bundle.main.path(forResource: "nameoftheyourjsonTextfile", ofType: "json")
let contentData = FileManager.default.contents(atPath: filePath!)
let content = NSString(data: contentData!, encoding: String.Encoding.utf8.rawValue) as? String
print(content)
let json = try! JSONSerialization.jsonObject(with: contentData!) as! NSDictionary
print(json)
let app = json.object(forKey: "Scenes") as! NSArray!
let _ : NSDictionary
for dict in app! {
let colorNam = (dict as AnyObject).object(forKey: "color") as! String
print("colors are \(colorNam)")
// let colour = UIColor(hexString: colorNam) {
// colorsArray.append(colour.cgColor)
// colorsArray.append(colorNam as! UIColor)
let value = (dict as AnyObject).object(forKey: "value") as! String
print("the values are \(value)")
valuesArray.append(value)
let images = (dict as AnyObject).object(forKey: "image") as! String
let url = URL(string: images as String)
let data = try? Data(contentsOf: url!)
print(data)
let image1 = UIImage(data: data!)! as UIImage
imagesArray.append(image1)
print(image1)
}

It is recommended to read and write files asynchronously! and it's so easy to do in pure Swift,
here is the protocol:
protocol FileRepository {
func read(from path: String) throws -> String
func readAsync(from path: String, completion: #escaping (Result<String, Error>) -> Void)
func write(_ string: String, to path: String) throws
func writeAsync(_ string: String, to path: String, completion: #escaping (Result<Void, Error>) -> Void)
}
As you can see it allows you to read and write files synchronously or asynchronously.
Here is my implementation in Swift 5:
class DefaultFileRepository {
// MARK: Properties
let queue: DispatchQueue = .global()
let fileManager: FileManager = .default
lazy var baseURL: URL = {
try! fileManager
.url(for: .libraryDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
.appendingPathComponent("MyFiles")
}()
// MARK: Private functions
private func doRead(from path: String) throws -> String {
let url = baseURL.appendingPathComponent(path)
var isDir: ObjCBool = false
guard fileManager.fileExists(atPath: url.path, isDirectory: &isDir) && !isDir.boolValue else {
throw ReadWriteError.doesNotExist
}
let string: String
do {
string = try String(contentsOf: url)
} catch {
throw ReadWriteError.readFailed(error)
}
return string
}
private func doWrite(_ string: String, to path: String) throws {
let url = baseURL.appendingPathComponent(path)
let folderURL = url.deletingLastPathComponent()
var isFolderDir: ObjCBool = false
if fileManager.fileExists(atPath: folderURL.path, isDirectory: &isFolderDir) {
if !isFolderDir.boolValue {
throw ReadWriteError.canNotCreateFolder
}
} else {
do {
try fileManager.createDirectory(at: folderURL, withIntermediateDirectories: true)
} catch {
throw ReadWriteError.canNotCreateFolder
}
}
var isDir: ObjCBool = false
guard !fileManager.fileExists(atPath: url.path, isDirectory: &isDir) || !isDir.boolValue else {
throw ReadWriteError.canNotCreateFile
}
guard let data = string.data(using: .utf8) else {
throw ReadWriteError.encodingFailed
}
do {
try data.write(to: url)
} catch {
throw ReadWriteError.writeFailed(error)
}
}
}
extension DefaultFileRepository: FileRepository {
func read(from path: String) throws -> String {
try queue.sync { try self.doRead(from: path) }
}
func readAsync(from path: String, completion: #escaping (Result<String, Error>) -> Void) {
queue.async {
do {
let result = try self.doRead(from: path)
completion(.success(result))
} catch {
completion(.failure(error))
}
}
}
func write(_ string: String, to path: String) throws {
try queue.sync { try self.doWrite(string, to: path) }
}
func writeAsync(_ string: String, to path: String, completion: #escaping (Result<Void, Error>) -> Void) {
queue.async {
do {
try self.doWrite(string, to: path)
completion(.success(Void()))
} catch {
completion(.failure(error))
}
}
}
}
enum ReadWriteError: LocalizedError {
// MARK: Cases
case doesNotExist
case readFailed(Error)
case canNotCreateFolder
case canNotCreateFile
case encodingFailed
case writeFailed(Error)
}

write in ViewDidLoad
var error: NSError?
var paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true)
var documentsDirectory = paths.first as String
var dataPath = documentsDirectory.stringByAppendingPathComponent("MyFolder")
if !NSFileManager.defaultManager().fileExistsAtPath(dataPath) {
NSFileManager.defaultManager().createDirectoryAtPath(dataPath, withIntermediateDirectories: false, attributes: nil, error: &error)
} else {
println("not creted or exist")
}
func listDocumentDirectoryfiles() -> [String] {
if let documentDirectory = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true).first as? String {
let myFilePath = documentDirectory.stringByAppendingPathComponent("MyFolder")
return NSFileManager.defaultManager().contentsOfDirectoryAtPath(myFilePath, error: nil) as [String]
}
return []
}

func writeToDocumentsFile(fileName:String,value:String) {
let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as NSString
let path = documentsPath.appendingPathComponent(fileName)
do{
try value.write(toFile: path, atomically: true, encoding: String.Encoding.utf8)
}catch{
}
}
func readFromDocumentsFile(fileName:String) -> String {
let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as NSString
let path = documentsPath.appendingPathComponent(fileName)
let checkValidation = FileManager.default
var file:String
if checkValidation.fileExists(atPath: path) {
do{
try file = NSString(contentsOfFile: path, encoding: String.Encoding.utf8.rawValue) as String
}catch{
file = ""
}
} else {
file = ""
}
return file
}

Earlier solutions answers question, but in my case deleting old content of file while writing was a problem.
So, I created piece of code for writing to file in documents directory without deleting previous content. You probably need better error handling, but I believe it's good starting point. Swift 4.
Usuage:
let filename = "test.txt"
createOrOverwriteEmptyFileInDocuments(filename: filename)
if let handle = getHandleForFileInDocuments(filename: filename) {
writeString(string: "aaa", fileHandle: handle)
writeString(string: "bbb", fileHandle: handle)
writeString(string: "\n", fileHandle: handle)
writeString(string: "ccc", fileHandle: handle)
}
Helper methods:
func createOrOverwriteEmptyFileInDocuments(filename: String){
guard let dir = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else {
debugPrint("ERROR IN createOrOverwriteEmptyFileInDocuments")
return
}
let fileURL = dir.appendingPathComponent(filename)
do {
try "".write(to: fileURL, atomically: true, encoding: .utf8)
}
catch {
debugPrint("ERROR WRITING STRING: " + error.localizedDescription)
}
debugPrint("FILE CREATED: " + fileURL.absoluteString)
}
private func writeString(string: String, fileHandle: FileHandle){
let data = string.data(using: String.Encoding.utf8)
guard let dataU = data else {
debugPrint("ERROR WRITING STRING: " + string)
return
}
fileHandle.seekToEndOfFile()
fileHandle.write(dataU)
}
private func getHandleForFileInDocuments(filename: String)->FileHandle?{
guard let dir = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else {
debugPrint("ERROR OPENING FILE")
return nil
}
let fileURL = dir.appendingPathComponent(filename)
do {
let fileHandle: FileHandle? = try FileHandle(forWritingTo: fileURL)
return fileHandle
}
catch {
debugPrint("ERROR OPENING FILE: " + error.localizedDescription)
return nil
}
}

Swift 3.x - 5.x
The Best Example is to Create a Local Logfile with an Extension .txt
that can visible and show in the "Files App" with current date and Time as a File Name
just add this code in info.plist enable these two features
UIFileSharingEnabled
LSSupportsOpeningDocumentsInPlace
and this Function Below
var logfileName : String = ""
func getTodayString() -> String{
let date = Date()
let calender = Calendar.current
let components = calender.dateComponents([.year,.month,.day,.hour,.minute,.second], from: date)
let year = components.year
let month = components.month
let day = components.day
let hour = components.hour
let minute = components.minute
let second = components.second
let today_string = String(year!) + "-" + String(month!) + "-" + String(day!) + "-" + String(hour!) + "" + String(minute!) + "" + String(second!)+".txt"
return today_string
}
func LogCreator(){
logfileName = getTodayString()
print("LogCreator: Logfile Generated Named: \(logfileName)")
let file = logfileName //this is the file. we will write to and read from it
let text = "some text" //just a text
if let dir = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first {
let fileURL = dir.appendingPathComponent(file)
let documentPath = NSSearchPathForDirectoriesInDomains(.documentDirectory,.userDomainMask, true)[0]
print("LogCreator: The Logs are Stored at location \(documentPath)")
//writing
do {
try text.write(to: fileURL, atomically: false, encoding: .utf8)
}
catch {/* error handling here */}
//reading
do {
let text2 = try String(contentsOf: fileURL, encoding: .utf8)
print("LogCreator: The Detail log are :-\(text2)")
}
catch {/* error handling here */}
}
}
[1]: https://i.stack.imgur.com/4eg12.png

Xcode 8.3.2 Swift 3.x. Using NSKeyedArchiver and NSKeyedUnarchiver
Reading file from documents
let documentsDirectoryPathString = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first!
let documentsDirectoryPath = NSURL(string: documentsDirectoryPathString)!
let jsonFilePath = documentsDirectoryPath.appendingPathComponent("Filename.json")
let fileManager = FileManager.default
var isDirectory: ObjCBool = false
if fileManager.fileExists(atPath: (jsonFilePath?.absoluteString)!, isDirectory: &isDirectory) {
let finalDataDict = NSKeyedUnarchiver.unarchiveObject(withFile: (jsonFilePath?.absoluteString)!) as! [String: Any]
}
else{
print("File does not exists")
}
Write file to documents
NSKeyedArchiver.archiveRootObject(finalDataDict, toFile:(jsonFilePath?.absoluteString)!)

Trying to share a json string in a file with an activity view controller

iOS 11, Swift 4
Trying to use an activity view controller to share a json string I have just created, and I think I am almost there, but struggling to attach a file with the controller. I got this code.
let encoder = JSONEncoder()
if let jsonData = try? encoder.encode(w2GA) {
if let jsonString = String(data: jsonData, encoding: .utf8) {
let documentsDirectoryURL = try! FileManager().url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
let file2ShareURL = documentsDirectoryURL.appendingPathComponent("blah.json")
print(jsonString)
do {
let encodedData = try? JSONEncoder().encode(jsonString)
try encodedData?.write(to: file2ShareURL)
let activityViewController = UIActivityViewController(activityItems: [file2ShareURL], applicationActivities: nil)
activityViewController.popoverPresentationController?.sourceView = self.view
self.present(activityViewController, animated: true, completion: nil)
} catch {
print(error)
}
}
}
I am getting the error message:
file:///var/mobile/Containers/Data/Application/FD6E9F52-405F-4E66-927F-DCB7EDB0BF25/Documents/blah.json
Attachments Error confirming URL is readable
Pretty sure the file is there? is this some sort of race hazard perhaps? If I replace the URL with the jsonString it works! So I get a jsonString looking like this basically.
[{"imageURL":"http://","latitude":46.819945794990176,"name":"Clue 1","longitude":8.2581710034376599,"hint":"Hint"},{"imageURL":"http://","latitude":47.433033706679716,"name":"Clue 2","longitude":8.8540648624925371,"hint":"Hint"},{"imageURL":"http://","latitude":46.785125219263776,"name":"Clue","longitude":9.6534346734197598,"hint":"Hint"}]

Do you need to save this as a file?
Surely the simplest approach to this is to pass the JSON string as a variable?
Example:
let activityViewController = UIActivityViewController(activityItems: [jsonString], applicationActivities: nil)
EDIT
I've just noticed you've already tried this and it works. Apologies.
Ensure the JSONEncoder isn't throwing an exception and that the file exists before you try to pass the url to the UIActivityViewController
You can also try using the UIActivityItemProvider class as documented here

Ok, found the answer which is of course obvious! The file wasn't being created!
I made two changes, firstly I run the entire code block under the main thread, secondly I changed the lines writing out the json string which in the earlier version I encode twice!
DispatchQueue.main.async {
let encoder = JSONEncoder()
if let jsonData = try? encoder.encode(w2GA) {
if let jsonString = String(data: jsonData, encoding: .utf8) {
var documentsDirectoryURL = try! FileManager().url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
let file2ShareURL = documentsDirectoryURL.appendingPathComponent("blah.json")
do {
try jsonString.write(to: file2ShareURL, atomically: false, encoding: .utf8)
} catch {
print(error)
}
do {
let _ = try Data(contentsOf: file2ShareURL)
let activityViewController = UIActivityViewController(activityItems: [file2ShareURL], applicationActivities: nil)
activityViewController.popoverPresentationController?.sourceView = self.view
self.present(activityViewController, animated: true, completion: nil)
} catch {
print(error)
}
}
}
}

Realm accessed from incorrect thread when try to view pdf file again Swift 3

i have collection view and user can tap to download pdf file. If download complete, it shows the pdf file. But after pdf showed up and go back then tap the cell again to show the pdf again, it throws Realm accessed from incorrect thread.
Here's my code to download file:
func downloadData(_ magazineObject: Magazine, cell: magazineCell) {
Alamofire.download(magazineObject.urlMagazine, method: .get, encoding: JSONEncoding.default, to: destination)
.downloadProgress(queue: DispatchQueue.global(qos: .utility)) { progress in
DispatchQueue.main.async() {
self.percentProgressFinal = Float(progress.fractionCompleted)
magazineObject.progressBarDownload = progress.fractionCompleted.roundToPlaces(places: 2)
magazineObject.progressBarTitle = Float(self.displayFinalLabelPercent).cleanValue
}
}
.validate { request, response, temporaryURL, destinationURL in
self.localPath = destinationURL
magazineObject.pathDatabase = String(describing: self.localPath!)
magazineObject.progressBarDownload = Double(self.percentProgressFinal)
magazineObject.progressBarTitle = Float(self.displayFinalLabelPercent).cleanValue
magazineObject.statusDarkViewAfterRelaunch = 1
let mainStoryBoard:UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let vc:PDFKBasicPDFViewer = mainStoryBoard.instantiateViewController(withIdentifier: "NEXT") as! PDFKBasicPDFViewer
let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
let filePath = "\(documentsPath)/\(magazineObject.title).pdf"
let document: PDFKDocument = PDFKDocument(contentsOfFile: filePath, password: nil)
vc.loadDocument(document)
self.navigationController?.pushViewController(vc, animated: true)
magazineObject.statusDownload = self.statusDatabase
let realm = try! Realm()
try! realm.write {
realm.add(magazineObject)
}
return .success
}
}
and show the file if already downloaded:
if statusGlobal {
if magazineObject.statusDownload == 0 {
magazineObject.statusDownload = 1
//Alamofire Request
downloadData(magazineObject, cell: cell)
cell.progressDownload.isHidden = false
cell.progressLabel.isHidden = false
} else {
let mainStoryBoard:UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let vc:PDFKBasicPDFViewer = mainStoryBoard.instantiateViewController(withIdentifier: "NEXT") as! PDFKBasicPDFViewer
let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
let filePath = "\(documentsPath)/\(magazineObject.title).pdf"
let document: PDFKDocument = PDFKDocument(contentsOfFile: filePath, password: nil)
vc.loadDocument(document)
self.navigationController?.pushViewController(vc, animated: true)
}
}
}
but if i re-run the simulator, it can show my pdf file.

I solve it by creating another variables
let newMagazineObject = Magazine()
newMagazineObject.id = magazineObject.id
newMagazineObject.pathDatabase = magazineObject.pathDatabase
newMagazineObject.progressBarDownload = magazineObject.progressBarDownload
newMagazineObject.progressBarTitle = magazineObject.progressBarTitle
newMagazineObject.statusDarkViewAfterRelaunch = magazineObject.statusDarkViewAfterRelaunch
newMagazineObject.statusDownload = magazineObject.statusDownload
let realm = try! Realm()
try! realm.write {
realm.add(newMagazineObject)
}

Use Xcode's exception breakpoints to set a breakpoint on C++ exceptions being thrown, then look up the stack trace of where the "incorrect thread" exception is thrown to see which line of your code is triggering the exception. From there, you should be able to determine which Realm object you're incorrectly sharing across threads.

reading from .plist always returns nil

All of my attempts to read from a plist have resulted in a nil value returned, I've tried this in several ways on both Xcode 6 & Xcode beta 7. Also, there are quite a few similar questions on stack, I've tried many of them, but none of them resolve this issue.
I've added my words.plist by clicking on:
{my project} > targets > build phases > copy Bundle Resources
Then I tried several variations of the following code in my ViewController:
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true) as NSArray
let documentsDirectory = paths[0] as! String
let path = documentsDirectory.stringByAppendingPathComponent("words.plist")
let fileManager = NSFileManager.defaultManager()
//check if file exists
if(!fileManager.fileExistsAtPath(path)) {
// If it doesn't, copy it from the default file in the Bundle
if let bundlePath = NSBundle.mainBundle().pathForResource("words", ofType: "plist") {
let resultDictionary = NSMutableDictionary(contentsOfFile: bundlePath)
println("Bundle words file is --> \(resultDictionary?.description)") // this is nil!!!
fileManager.copyItemAtPath(bundlePath, toPath: path, error: nil)
} else {
println("words not found. Please, make sure it is part of the bundle.")
}
} else {
println("words already exits at path.")
// use this to delete file from documents directory
//fileManager.removeItemAtPath(path, error: nil)
}
print("entering if-let")
if let pfr = NSBundle.mainBundle().pathForResource("words", ofType: "plist") {
print("\nin let\n")
print(pfr)
print("\nentering dict if-let\n")
if let dict = NSDictionary(contentsOfFile: path) as? Dictionary<String, AnyObject> {
// use swift dictionary as normal
print("\nin let\n")
print(dict)
}
}
}
Question
Why am I getting a nil value and whats the proper way to add a plist file and read from it?
update:
inside my if statement the following is nil:
let resultDictionary = NSMutableDictionary(contentsOfFile: bundlePath)
println("Bundle words file is --> \(resultDictionary?.description)") // this is nil!!!
To me, this would indicate that either Xcode doesn't know about my words.plist file, or that I'm pointing my bundlePath to the wrong location.

the issue:
As #Steven Fisher stated, in the comments. My .plist file was an Array and not an NSDictionary. So I just had to switch two lines from my code:
let resultDictionary = NSMutableDictionary(contentsOfFile: bundlePath)
to
let resultDictionary = NSMutableArray(contentsOfFile: bundlePath)
and also
if let dict = NSDictionary(contentsOfFile: path) { //...
to
if let dict = NSArray(contentsOfFile: path) { //..
final working code:
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true) as NSArray
let documentsDirectory = paths[0] as! String
let path = documentsDirectory.stringByAppendingPathComponent("words.plist")
let fileManager = NSFileManager.defaultManager()
//check if file exists
if(!fileManager.fileExistsAtPath(path)) {
// If it doesn't, copy it from the default file in the Bundle
if let bundlePath = NSBundle.mainBundle().pathForResource("words", ofType: "plist") {
let resultDictionary = NSMutableArray(contentsOfFile: bundlePath)
println("Bundle words file is --> \(resultDictionary?.description)")
fileManager.copyItemAtPath(bundlePath, toPath: path, error: nil)
} else {
println("words not found. Please, make sure it is part of the bundle.")
}
} else {
println("words already exits at path.")
// use this to delete file from documents directory
//fileManager.removeItemAtPath(path, error: nil)
}
print("entering if-let")
if let pfr = NSBundle.mainBundle().pathForResource("words", ofType: "plist") {
print("\nin let\n")
print(pfr)
print("\nentering dict if-let\n")
if let dict = NSArray(contentsOfFile: pfr) {
// use swift dictionary as normal
print("\nin let\n")
print(dict)
}
}
}