Saving image and then loading it in Swift (iOS) - ios

Question

I am saving an image using saveImage.
func saveImage (image: UIImage, path: String ) -> Bool{
let pngImageData = UIImagePNGRepresentation(image)
//let jpgImageData = UIImageJPEGRepresentation(image, 1.0) // if you want to save as JPEG
print("!!!saving image at: \(path)")
let result = pngImageData!.writeToFile(path, atomically: true)
return result
}
New info:
Saving file does not work properly ("[-] ERROR SAVING FILE" is printed)--
// save your image here into Document Directory
let res = saveImage(tempImage, path: fileInDocumentsDirectory("abc.png"))
if(res == true){
print ("[+] FILE SAVED")
}else{
print ("[-] ERROR SAVING FILE")
}
Why doesn't the saveImage function save the image? Access rights?
Older info:
The debug info says:
!!!saving image at: file:///var/mobile/Applications/BDB992FB-E378-4719-B7B7-E9A364EEE54B/Documents/tempImage
Then I retrieve this location using
fileInDocumentsDirectory("tempImage")
The result is correct.
Then I am loading the file using this path
let image = UIImage(contentsOfFile: path)
if image == nil {
print("missing image at: \(path)")
}else{
print("!!!IMAGE FOUND at: \(path)")
}
The path is correct, but the message is "missing image at..". Is the file somehow inaccessible or not stored? What can be a reason for this behavior?
I am testing this code on iphone 4 with ios 7 and iphone 5 with ios 7 simulator.
Edit:
1. The fileInDocumentsDirectory function
func fileInDocumentsDirectory(filename: String) -> String {
let documentsURL = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0]
let fileURL = documentsURL.URLByAppendingPathComponent(filename).absoluteString
return fileURL
}

Answer 1

This function will save an image in the documents folder:
func saveImage(image: UIImage) -> Bool {
guard let data = UIImageJPEGRepresentation(image, 1) ?? UIImagePNGRepresentation(image) else {
return false
}
guard let directory = try? FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false) as NSURL else {
return false
}
do {
try data.write(to: directory.appendingPathComponent("fileName.png")!)
return true
} catch {
print(error.localizedDescription)
return false
}
}
To use:
let success = saveImage(image: UIImage(named: "image.png")!)
This function will get that image:
func getSavedImage(named: String) -> UIImage? {
if let dir = try? FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false) {
return UIImage(contentsOfFile: URL(fileURLWithPath: dir.absoluteString).appendingPathComponent(named).path)
}
return nil
}
To use:
if let image = getSavedImage(named: "fileName") {
// do something with image
}

Answer 2

iOS 13+ Swift 5.1
iOS 12 introduced some API Changes.
func saveImage(imageName: String, image: UIImage) {
guard let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else { return }
let fileName = imageName
let fileURL = documentsDirectory.appendingPathComponent(fileName)
guard let data = image.jpegData(compressionQuality: 1) else { return }
//Checks if file exists, removes it if so.
if FileManager.default.fileExists(atPath: fileURL.path) {
do {
try FileManager.default.removeItem(atPath: fileURL.path)
print("Removed old image")
} catch let removeError {
print("couldn't remove file at path", removeError)
}
}
do {
try data.write(to: fileURL)
} catch let error {
print("error saving file with error", error)
}
}
func loadImageFromDiskWith(fileName: String) -> UIImage? {
let documentDirectory = FileManager.SearchPathDirectory.documentDirectory
let userDomainMask = FileManager.SearchPathDomainMask.userDomainMask
let paths = NSSearchPathForDirectoriesInDomains(documentDirectory, userDomainMask, true)
if let dirPath = paths.first {
let imageUrl = URL(fileURLWithPath: dirPath).appendingPathComponent(fileName)
let image = UIImage(contentsOfFile: imageUrl.path)
return image
}
return nil
}

Answer 3

Details
Xcode Version 10.2 (10E125), Swift 5
Solution
// save
extension UIImage {
func save(at directory: FileManager.SearchPathDirectory,
pathAndImageName: String,
createSubdirectoriesIfNeed: Bool = true,
compressionQuality: CGFloat = 1.0) -> URL? {
do {
let documentsDirectory = try FileManager.default.url(for: directory, in: .userDomainMask,
appropriateFor: nil,
create: false)
return save(at: documentsDirectory.appendingPathComponent(pathAndImageName),
createSubdirectoriesIfNeed: createSubdirectoriesIfNeed,
compressionQuality: compressionQuality)
} catch {
print("-- Error: \(error)")
return nil
}
}
func save(at url: URL,
createSubdirectoriesIfNeed: Bool = true,
compressionQuality: CGFloat = 1.0) -> URL? {
do {
if createSubdirectoriesIfNeed {
try FileManager.default.createDirectory(at: url.deletingLastPathComponent(),
withIntermediateDirectories: true,
attributes: nil)
}
guard let data = jpegData(compressionQuality: compressionQuality) else { return nil }
try data.write(to: url)
return url
} catch {
print("-- Error: \(error)")
return nil
}
}
}
// load from path
extension UIImage {
convenience init?(fileURLWithPath url: URL, scale: CGFloat = 1.0) {
do {
let data = try Data(contentsOf: url)
self.init(data: data, scale: scale)
} catch {
print("-- Error: \(error)")
return nil
}
}
}
Usage
// save image (way 1)
let path = "photo/temp/album1/img.jpg"
guard let img = UIImage(named: "img"),
let url = img.save(at: .documentDirectory,
pathAndImageName: path) else { return }
print(url)
// get image from directory
guard let img2 = UIImage(fileURLWithPath: url) else { return }
// save image (way 2)
let tempDirectoryUrl = URL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(path)
guard let url2 = img2.save(at: tempDirectoryUrl) else { return }
print(url2)
Check results
open the iOS simulator directory

Answer 4

You should save image name with extension so your path should be like,
///var/mobile/Applications/BDB992FB-E378-4719-B7B7-E9A364EEE54B/Documents/tempImage.png
And second thing replace below line,
let result = pngImageData!.writeToFile(path, atomically: true)
with
let result = pngImageData!.writeToFile(path, atomically: false)
You need to set false as parameter of atomically.
atomically:
If true, the data is written to a backup file, and then—assuming no errors occur—the backup file is renamed to the name specified by path; otherwise, the data is written directly to path.
Hope this will help :)

Answer 5

Save image in local Xcode Documents directory
Pass in your image and the name you want to call it (you choose what you want fileName to be).
func saveImageLocally(image: UIImage, fileName: String) {
// Obtaining the Location of the Documents Directory
let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
// Creating a URL to the name of your file
let url = documentsDirectory.appendingPathComponent(fileName)
if let data = image.pngData() {
do {
try data.write(to: url) // Writing an Image in the Documents Directory
} catch {
print("Unable to Write \(fileName) Image Data to Disk")
}
}
}
Read
Use the same fileName as when you saved it
func getImageFromName(fileName: String) {
let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
let url = documentsDirectory.appendingPathComponent(fileName)
if let imageData = try? Data(contentsOf: url) {
let image = UIImage(data: imageData) // HERE IS YOUR IMAGE! Do what you want with it!
} else {
print("Couldn't get image for \(fileName)")
}
}

Answer 6

Ashish's comment has a clue to the answer. If you read the docs on UIImage(contentsOfFile:) they say
path The path to the file. This path should include the filename
extension that identifies the type of the image data.
The imageNamed call is smart enough to try the .png and .jpg extensions, but the contentsOfFile call expects a full path including extension.

Answer 7

If you want to load image from server you can do like below
let url = URL(string: "http://live-wallpaper.net/iphone/img/app/i/p/iphone-4s-wallpapers-mobile-backgrounds-dark_2466f886de3472ef1fa968033f1da3e1_raw_1087fae1932cec8837695934b7eb1250_raw.jpg")
URLSession.shared.dataTask(with: url!) { (data, response, error) in
guard
let httpURLResponse = response as? HTTPURLResponse, httpURLResponse.statusCode == 200,
let mimeType = response?.mimeType, mimeType.hasPrefix("image"),
let data = data, error == nil
else { return }
DispatchQueue.main.async() { () -> Void in
let fileManager = FileManager.default
let paths = (NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as NSString).appendingPathComponent("apple.jpg")
print(paths)
fileManager.createFile(atPath: paths as String, contents: data, attributes: nil)
}}.resume()

Answer 8

You can actually use PHPhotoLibrary to do that.
Here is the code for saving the image and fetching the image url.
extension UIImage {
func saveToPhotoLibrary(completion: #escaping (URL?) -> Void) {
var localeId: String?
PHPhotoLibrary.shared().performChanges({
let request = PHAssetChangeRequest.creationRequestForAsset(from: self)
localeId = request.placeholderForCreatedAsset?.localIdentifier
}) { (isSaved, error) in
guard isSaved else {
debugPrint(error?.localizedDescription)
completion(nil)
return
}
guard let localeId = localeId else {
completion(nil)
return
}
let fetchOptions = PHFetchOptions()
fetchOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)]
let result = PHAsset.fetchAssets(withLocalIdentifiers: [localeId], options: fetchOptions)
guard let asset = result.firstObject else {
completion(nil)
return
}
getPHAssetURL(of: asset) { (phAssetUrl) in
completion(phAssetUrl)
}
}
}
static func getPHAssetURL(of asset: PHAsset, completionHandler : #escaping ((_ responseURL : URL?) -> Void))
{
let options: PHContentEditingInputRequestOptions = PHContentEditingInputRequestOptions()
options.canHandleAdjustmentData = {(adjustmeta: PHAdjustmentData) -> Bool in
return true
}
asset.requestContentEditingInput(with: options, completionHandler: { (contentEditingInput, info) in
completionHandler(contentEditingInput!.fullSizeImageURL)
})
}
}

Answer 9

You have to create a directory in the Documents directory to be able to store a file.

Answer 10

Swift 5
func saveImage(image: UIImage) -> Bool{
guard let data = image.jpegData(compressionQuality: 1) ?? image.pngData() else {
return false
}
guard let directory = try? FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false) as NSURL else {
return false
}
do{
try data.write(to: directory.appendingPathComponent("\(txtNom.text!).png")!)
print(directory)
print(data)
print("si se pudo")
return true
} catch {
print(error.localizedDescription)
return false
}
} // saveImage

Answer 11

I found the solution on StackOverFlow some time ago. I didn't remember the author
Assuming yourImage is UIImage()
let ciImage = yourImage!.ciImage
let context = CIContext()
let cgImage = context.createCGImage(ciImage!, from: ciImage!.extent)
let uiImage = UIImage(cgImage: cgImage!)
UIImageWriteToSavedPhotosAlbum(uiImage, self,
#selector(self.image(_:didFinishSavingWithError:contextInfo:)), nil)
and this function
#objc func image(_ image: UIImage, didFinishSavingWithError error: Error?, contextInfo: UnsafeRawPointer) {
if let error = error {
// we got back an error!
let ac = UIAlertController(title: "Save error", message: error.localizedDescription, preferredStyle: .alert)
ac.addAction(UIAlertAction(title: "OK", style: .default))
present(ac, animated: true)
} else {
let ac = UIAlertController(title: "Saved!", message: "Your altered image has been saved to your photos.", preferredStyle: .alert)
ac.addAction(UIAlertAction(title: "OK", style: .default))
present(ac, animated: true)
}
}