guard let imageData = try? Data(contentsOf: bundleURL) else {
print("Cannot turn image named \"\(gifNamed)\" into NSData")
return nil
}
I want to use GIF path in documents directory and extract the data from it not with bundleUrl but with GIF path in : file:///var/mobile/Containers/Data/Application/5615E8E1-F120-4171-A7CE-B2A9F2E8FC19/Documents/test.gif
If I understand correctly you want to get data from gif that is located in you app's Documents directory. Your code may look like that:
func getDataOf(gifNamed: String) -> Data? {
// Get url of Documents directory
let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
guard let documentsDirectory = paths.first else { return nil }
// Get url of your gif
guard let gifURL = documentsDirectory.appendingPathComponent(gifNamed) else { return nil }
// Extract the data of your gif
var data: Data?
do {
data = try Data(contentsOf: bundleURL)
} catch {
print(error)
}
return data
}
I am building an application in which i am using FileManager to save some images using device camera. So for Now I am saving file name as Doc-Time.
I am using below code,
func saveImageToDocumentDirectory(image: UIImage ) {
let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "hh:mm:ss"
let fileName = "Doc-" + dateFormatter.string(from: Date())
let fileURL = documentsDirectory.appendingPathComponent(fileName
)
if let data = image.jpegData(compressionQuality: 1.0),!FileManager.default.fileExists(atPath: fileURL.path){
do {
try data.write(to: fileURL)
print("file saved")
} catch {
print("error saving file:", error)
}
}
}
But Here i want to as, Doc-1,Doc-2, Doc-3....
How can i do that?
You can achieve this by simply storing the next index of the image. Like first the index should be 1 when you used named the image as Doc-1 then the index has 2 in it and so on....
One way to store this index in UserDefaults like:
var nextImageIndex: Int {
UserDefaults.standard.integer(forKey: "NextImageIndex") + 1 //+1 if you want to start with 1
}
func incrementImageIndex() {
UserDefaults.standard.setValue(nextImageIndex, forKey: "NextImageIndex")
}
Put the above code somewhere in UIViewController to see it works.
Here is your updated method...
func saveImageToDocumentDirectory(image: UIImage ) {
guard let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else {
return
}
let fileName = "Doc-\(nextImageIndex)"
let fileURL = documentsDirectory.appendingPathComponent(fileName)
let fileAlreadyExists = FileManager.default.fileExists(atPath: fileURL.path)
if let data = image.jpegData(compressionQuality: 1.0), !fileAlreadyExists {
do {
try data.write(to: fileURL)
incrementImageIndex()
print("file saved")
} catch {
print("error saving file:", error)
}
}
}
Create a variable to store the document count and increment it every time your save to the document directory, then use that value in the string.
let documentKey = "documentIndex"
#objc var documentIndex: Int {
get { UserDefaults.value(forKey: documentKey) as? Int ?? 0 }
set { UserDefaults.setValue(newValue, forKey: documentKey) }
}
func saveImageToDocumentDirectory(image: UIImage ) {
let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
documentIndex += 1
let fileName = "Doc-\(documentIndex)"
let fileURL = documentsDirectory.appendingPathComponent(fileName
)
if let data = image.jpegData(compressionQuality: 1.0),!FileManager.default.fileExists(atPath: fileURL.path){
do {
try data.write(to: fileURL)
print("file saved")
} catch {
print("error saving file:", error)
}
}
}
I am trying to delete a pin on map, I have several of them on the map stored in the documents directory.I want to delete only a single pin at time, but once I call my delete method, I get this error- The file “SavedLocations” couldn’t be opened. How do I delete a single pin saved in the documents directory? Please help, Thank you.
func getDocumentsDirectory() -> URL {
let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
return paths[0]
}
//Load method
func loadData() {
print("loaded data")
let filename = getDocumentsDirectory().appendingPathComponent("SavedLocations")
do {
let data = try Data(contentsOf: filename)
locations = try JSONDecoder().decode([CodableMKPointAnnotation].self, from: data)
} catch {
print("Unable to load saved data")
}
}
//Save method
func saveData() {
print("saved data")
do {
let filename = getDocumentsDirectory().appendingPathComponent("SavedLocations")
// print(filename)
let data = try JSONEncoder().encode(self.locations)
try data.write(to: filename, options: [.atomicWrite, .completeFileProtection])
} catch {
print("Unable to save data")
}
}
//Delete method
func delete() {
let fileManager = FileManager.default
let filename = getDocumentsDirectory().appendingPathComponent("SavedLocations")
print("Pin deleted")
print(filename)
do {
let items = try fileManager.contentsOfDirectory(at: filename, includingPropertiesForKeys: .none, options: .skipsHiddenFiles)
print(items)
for item in items {
try fileManager.removeItem(at: item)
print(item)
}
} catch let error {
print("\(error.localizedDescription)")
}
}
Change this method to:
func delete() {
let fileManager = FileManager.default
let filename = getDocumentsDirectory().appendingPathComponent("SavedLocations")
print("Pin deleted")
print(filename)
do {
let items = try fileManager.contentsOfDirectory(at: filename, includingPropertiesForKeys: .none, options: .skipsHiddenFiles)
print(items)
if (newArray.count > 0){
try fileManager.removeItem(at: items[0])
}
} catch let error {
print("\(error.localizedDescription)")
}
}
I have been asked to build an app that shows a catalog with AR, so what I need to do is pretty simple: when an user chooses a product I must load the image recovered in base64 from the server into a plane object. Is this possible with swift - arkit ? Or are all the sprites/images/textures required to be previously loaded into the assets folder?
You can definitely download resources from a server, save them to the device (e.g in NSDocumentsDirectory), and then load with the file URL. I do it for a similar use case as yours -at least it sounds so, per the description you gave-
EDIT
Here's the relevant code. I use Alamofire to download from the server and ZIPFoundation for unzipping. I believe that if you just need to download an image, it'll be a bit simpler, probably not needing the unzip part.
let modelsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
func loadNodeWithID(_ id: String, completion: #escaping (SCNNode?) -> Void) {
// Check that assets for that model are not already downloaded
let fileManager = FileManager.default
let dirForModel = modelsDirectory.appendingPathComponent(id)
let dirExists = fileManager.fileExists(atPath: dirForModel.path)
if dirExists {
completion(loadNodeWithIdFromDisk(id))
} else {
let dumbURL = "http://yourserver/yourfile.zip"
downloadZip(from: dumbURL, at: id) {
if let url = $0 {
print("Downloaded and unzipped at: \(url.absoluteString)")
completion(self.loadNodeWithIdFromDisk(id))
} else {
print("Something went wrong!")
completion(nil)
}
}
}
}
func loadNodeWithIdFromDisk(_ id: String) -> SCNNode? {
let fileManager = FileManager.default
let dirForModel = modelsDirectory.appendingPathComponent(id)
do {
let files = try fileManager.contentsOfDirectory(atPath: dirForModel.path)
if let objFile = files.first(where: { $0.hasSuffix(".obj") }) {
let objScene = try? SCNScene(url: dirForModel.appendingPathComponent(objFile), options: nil)
let objNode = objScene?.rootNode.firstChild()
return objNode
} else {
print("No obj file in directory: \(dirForModel.path)")
return nil
}
} catch {
print("Could not enumarate files or load scene: \(error)")
return nil
}
}
func downloadZip(from urlString: String, at destFileName: String, completion: ((URL?) -> Void)?) {
print("Downloading \(urlString)")
let fullDestName = destFileName + ".zip"
let destination: DownloadRequest.DownloadFileDestination = { _, _ in
let fileURL = modelsDirectory.appendingPathComponent(fullDestName)
return (fileURL, [.removePreviousFile, .createIntermediateDirectories])
}
Alamofire.download(urlString, to: destination).response { response in
let error = response.error
if error == nil {
if let filePath = response.destinationURL?.path {
let nStr = NSString(string: filePath)
let id = NSString(string: nStr.lastPathComponent).deletingPathExtension
print(response)
print("file downloaded at: \(filePath)")
let fileManager = FileManager()
let sourceURL = URL(fileURLWithPath: filePath)
var destinationURL = modelsDirectory
destinationURL.appendPathComponent(id)
do {
try fileManager.createDirectory(at: destinationURL, withIntermediateDirectories: true, attributes: nil)
try fileManager.unzipItem(at: sourceURL, to: destinationURL)
completion?(destinationURL)
} catch {
completion?(nil)
print("Extraction of ZIP archive failed with error: \(error)")
}
} else {
completion?(nil)
print("File path not found")
}
} else {
// Handle error
completion?(nil)
}
}
}
I already have read Read and write data from text file
I need to append the data (a string) to the end of my text file.
One obvious way to do it is to read the file from disk and append the string to the end of it and write it back, but it is not efficient, especially if you are dealing with large files and doing in often.
So the question is "How to append string to the end of a text file, without reading the file and writing the whole thing back"?
so far I have:
let dir:NSURL = NSFileManager.defaultManager().URLsForDirectory(NSSearchPathDirectory.CachesDirectory, inDomains: NSSearchPathDomainMask.UserDomainMask).last as NSURL
let fileurl = dir.URLByAppendingPathComponent("log.txt")
var err:NSError?
// until we find a way to append stuff to files
if let current_content_of_file = NSString(contentsOfURL: fileurl, encoding: NSUTF8StringEncoding, error: &err) {
"\(current_content_of_file)\n\(NSDate()) -> \(object)".writeToURL(fileurl, atomically: true, encoding: NSUTF8StringEncoding, error: &err)
}else {
"\(NSDate()) -> \(object)".writeToURL(fileurl, atomically: true, encoding: NSUTF8StringEncoding, error: &err)
}
if err != nil{
println("CANNOT LOG: \(err)")
}
Here's an update for PointZeroTwo's answer in Swift 3.0, with one quick note - in the playground testing using a simple filepath works, but in my actual app I needed to build the URL using .documentDirectory (or which ever directory you chose to use for reading and writing - make sure it's consistent throughout your app):
extension String {
func appendLineToURL(fileURL: URL) throws {
try (self + "\n").appendToURL(fileURL: fileURL)
}
func appendToURL(fileURL: URL) throws {
let data = self.data(using: String.Encoding.utf8)!
try data.append(fileURL: fileURL)
}
}
extension Data {
func append(fileURL: URL) throws {
if let fileHandle = FileHandle(forWritingAtPath: fileURL.path) {
defer {
fileHandle.closeFile()
}
fileHandle.seekToEndOfFile()
fileHandle.write(self)
}
else {
try write(to: fileURL, options: .atomic)
}
}
}
//test
do {
let dir: URL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last! as URL
let url = dir.appendingPathComponent("logFile.txt")
try "Test \(Date())".appendLineToURL(fileURL: url as URL)
let result = try String(contentsOf: url as URL, encoding: String.Encoding.utf8)
}
catch {
print("Could not write to file")
}
Thanks PointZeroTwo.
You should use NSFileHandle, it can seek to the end of the file
let dir:NSURL = NSFileManager.defaultManager().URLsForDirectory(NSSearchPathDirectory.CachesDirectory, inDomains: NSSearchPathDomainMask.UserDomainMask).last as NSURL
let fileurl = dir.URLByAppendingPathComponent("log.txt")
let string = "\(NSDate())\n"
let data = string.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)!
if NSFileManager.defaultManager().fileExistsAtPath(fileurl.path!) {
var err:NSError?
if let fileHandle = NSFileHandle(forWritingToURL: fileurl, error: &err) {
fileHandle.seekToEndOfFile()
fileHandle.writeData(data)
fileHandle.closeFile()
}
else {
println("Can't open fileHandle \(err)")
}
}
else {
var err:NSError?
if !data.writeToURL(fileurl, options: .DataWritingAtomic, error: &err) {
println("Can't write \(err)")
}
}
A variation over some of the posted answers, with following characteristics:
based on Swift 5
accessible as a static function
appends new entries to the end of the file, if it exists
creates the file, if it doesn't exist
no cast to NS objects (more Swiftly)
fails silently if the text cannot be encoded or the path does not exist
class Logger {
static var logFile: URL? {
guard let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else { return nil }
let formatter = DateFormatter()
formatter.dateFormat = "dd-MM-yyyy"
let dateString = formatter.string(from: Date())
let fileName = "\(dateString).log"
return documentsDirectory.appendingPathComponent(fileName)
}
static func log(_ message: String) {
guard let logFile = logFile else {
return
}
let formatter = DateFormatter()
formatter.dateFormat = "HH:mm:ss"
let timestamp = formatter.string(from: Date())
guard let data = (timestamp + ": " + message + "\n").data(using: String.Encoding.utf8) else { return }
if FileManager.default.fileExists(atPath: logFile.path) {
if let fileHandle = try? FileHandle(forWritingTo: logFile) {
fileHandle.seekToEndOfFile()
fileHandle.write(data)
fileHandle.closeFile()
}
} else {
try? data.write(to: logFile, options: .atomicWrite)
}
}
}
Here is a way to update a file in a much more efficient way.
let monkeyLine = "\nAdding a 🐵 to the end of the file via FileHandle"
if let fileUpdater = try? FileHandle(forUpdating: newFileUrl) {
// Function which when called will cause all updates to start from end of the file
fileUpdater.seekToEndOfFile()
// Which lets the caller move editing to any position within the file by supplying an offset
fileUpdater.write(monkeyLine.data(using: .utf8)!)
// Once we convert our new content to data and write it, we close the file and that’s it!
fileUpdater.closeFile()
}
Here's a version for Swift 2, using extension methods on String and NSData.
//: Playground - noun: a place where people can play
import UIKit
extension String {
func appendLineToURL(fileURL: NSURL) throws {
try self.stringByAppendingString("\n").appendToURL(fileURL)
}
func appendToURL(fileURL: NSURL) throws {
let data = self.dataUsingEncoding(NSUTF8StringEncoding)!
try data.appendToURL(fileURL)
}
}
extension NSData {
func appendToURL(fileURL: NSURL) throws {
if let fileHandle = try? NSFileHandle(forWritingToURL: fileURL) {
defer {
fileHandle.closeFile()
}
fileHandle.seekToEndOfFile()
fileHandle.writeData(self)
}
else {
try writeToURL(fileURL, options: .DataWritingAtomic)
}
}
}
// Test
do {
let url = NSURL(fileURLWithPath: "test.log")
try "Test \(NSDate())".appendLineToURL(url)
let result = try String(contentsOfURL: url)
}
catch {
print("Could not write to file")
}
In order to stay in the spirit of #PointZero Two.
Here an update of his code for Swift 4.1
extension String {
func appendLine(to url: URL) throws {
try self.appending("\n").append(to: url)
}
func append(to url: URL) throws {
let data = self.data(using: String.Encoding.utf8)
try data?.append(to: url)
}
}
extension Data {
func append(to url: URL) throws {
if let fileHandle = try? FileHandle(forWritingTo: url) {
defer {
fileHandle.closeFile()
}
fileHandle.seekToEndOfFile()
fileHandle.write(self)
} else {
try write(to: url)
}
}
}
Update: I wrote a blog post on this, which you can find here!
Keeping things Swifty, here is an example using a FileWriter protocol with default implementation (Swift 4.1 at the time of this writing):
To use this, have your entity (class, struct, enum) conform to this protocol and call the write function (fyi, it throws!).
Writes to the document directory.
Will append to the text file if the file exists.
Will create a new file if the text file doesn't exist.
Note: this is only for text. You could do something similar to write/append Data.
import Foundation
enum FileWriteError: Error {
case directoryDoesntExist
case convertToDataIssue
}
protocol FileWriter {
var fileName: String { get }
func write(_ text: String) throws
}
extension FileWriter {
var fileName: String { return "File.txt" }
func write(_ text: String) throws {
guard let dir = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else {
throw FileWriteError.directoryDoesntExist
}
let encoding = String.Encoding.utf8
guard let data = text.data(using: encoding) else {
throw FileWriteError.convertToDataIssue
}
let fileUrl = dir.appendingPathComponent(fileName)
if let fileHandle = FileHandle(forWritingAtPath: fileUrl.path) {
fileHandle.seekToEndOfFile()
fileHandle.write(data)
} else {
try text.write(to: fileUrl, atomically: false, encoding: encoding)
}
}
}
All answers (as of now) recreate the FileHandle for every write operation. This may be fine for most applications, but this is also rather inefficient: A syscall is made, and the filesystem is accessed each time you create the FileHandle.
To avoid creating the filehandle multiple times, use something like:
final class FileHandleBuffer {
let fileHandle: FileHandle
let size: Int
private var buffer: Data
init(fileHandle: FileHandle, size: Int = 1024 * 1024) {
self.fileHandle = fileHandle
self.size = size
self.buffer = Data(capacity: size)
}
deinit { try! flush() }
func flush() throws {
try fileHandle.write(contentsOf: buffer)
buffer = Data(capacity: size)
}
func write(_ data: Data) throws {
buffer.append(data)
if buffer.count > size {
try flush()
}
}
}
// USAGE
// Create the file if it does not yet exist
FileManager.default.createFile(atPath: fileURL.path, contents: nil)
let fileHandle = try FileHandle(forWritingTo: fileURL)
// Seek will make sure to not overwrite the existing content
// Skip the seek to overwrite the file
try fileHandle.seekToEnd()
let buffer = FileHandleBuffer(fileHandle: fileHandle)
for i in 0..<count {
let data = getData() // Your implementation
try buffer.write(data)
print(i)
}