Saving image and then loading it in Swift (iOS)
IosSwiftCachingFile ManagerImage CachingIos Problem Overview
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:
-
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}
Ios Solutions
Solution 1 - Ios
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
}
Solution 2 - Ios
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
}
Solution 3 - Ios
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
Solution 4 - Ios
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 :)
Solution 5 - Ios
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.
Solution 6 - Ios
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()
Solution 7 - Ios
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)")
}
}
Solution 8 - Ios
You have to create a directory in the Documents directory to be able to store a file.
Solution 9 - Ios
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
Solution 10 - Ios
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)
}
}
Solution 11 - Ios
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)
})
}
}