how to use writeToFile to save image in document directory? - ios

Question

// directoryPath is a URL from another VC
#IBAction func saveButtonTapped(sender: AnyObject) {
let directoryPath = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0] as NSURL
let urlString : NSURL = directoryPath.URLByAppendingPathComponent("Image1.png")
print("Image path : \(urlString)")
if !NSFileManager.defaultManager().fileExistsAtPath(directoryPath.absoluteString) {
UIImageJPEGRepresentation(self.image, 1.0)!.writeToFile(urlString.absoluteString, atomically: true)
displayImageAdded.text = "Image Added Successfully"
} else {
displayImageAdded.text = "Image Not Added"
print("image \(image))")
}
}
I am not getting any error but the Image is not getting saved in the document.

Answer 1

The problem there is that you are checking if the folder not exists but you should check if the file exists. Another issue in your code is that you need to use url.path instead of url.absoluteString. You are also saving a jpeg image using a "png" file extension. You should use "jpg".
edit/update:
Swift 4.2 or later
do {
// get the documents directory url
let documentsDirectory = try FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false)
print("documentsDirectory:", documentsDirectory.path)
// choose a name for your image
let fileName = "image.jpg"
// create the destination file url to save your image
let fileURL = documentsDirectory.appendingPathComponent(fileName)
// get your UIImage jpeg data representation and check if the destination file url already exists
if let data = image.jpegData(compressionQuality: 1),
!FileManager.default.fileExists(atPath: fileURL.path) {
// writes the image data to disk
try data.write(to: fileURL)
print("file saved")
}
} catch {
print("error:", error)
}
To write the image at the destination regardless if the image already exists or not you can use .atomic options, if you would like to avoid overwriting an existing image you can use withoutOverwriting instead:
try data.write(to: fileURL, options: [.atomic])

Answer 2

This is my answer for Swift 3, combining the 2 answers above:
let documentsDirectoryURL = try! FileManager().url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
// create a name for your image
let fileURL = documentsDirectoryURL.appendingPathComponent("Savedframe.png")
if !FileManager.default.fileExists(atPath: fileURL.path) {
do {
try UIImagePNGRepresentation(imageView.image!)!.write(to: fileURL)
print("Image Added Successfully")
} catch {
print(error)
}
} else {
print("Image Not Added")
}

Answer 3

An extension method in swift 4.2
import Foundation
import UIKit
extension UIImage {
func saveToDocuments(filename:String) {
let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
let fileURL = documentsDirectory.appendingPathComponent(filename)
if let data = self.jpegData(compressionQuality: 1.0) {
do {
try data.write(to: fileURL)
} catch {
print("error saving file to documents:", error)
}
}
}
}

Answer 4

#IBAction func saveButtonTapped(sender: AnyObject) {
let directoryPath = try! NSFileManager().URLForDirectory(.DocumentDirectory, inDomain: .UserDomainMask, appropriateForURL: nil, create: true)
let urlString : NSURL = directoryPath.URLByAppendingPathComponent("Image1.png")
print("Image path : \(urlString)")
if !NSFileManager.defaultManager().fileExistsAtPath(urlString.path!) {
UIImageJPEGRepresentation(self.image, 1.0)!.writeToFile(urlString.path! , atomically: true)
displayImageAdded.text = "Image Added Successfully"
} else {
displayImageAdded.text = "Image Not Added"
print("image \(image))")
}
}

Answer 5

Put the image in an NSData object; writing to a file with this class is a breeze, and it'll make the file size smaller.
By the way, I recommend NSPurgeableData. After saving the image, you can mark the object as purgeable, which will keep memory consumption. That may be a problem with your app, but might be with another you're crowding out.

Answer 6

In Swift 4.2 and Xcode 10.1
func saveImageInDocsDir() {
let image: UIImage? = yourImage//Here set your image
if !(image == nil) {
// get the documents directory url
let paths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
let documentsDirectory = paths[0] // Get documents folder
let dataPath = URL(fileURLWithPath: documentsDirectory).appendingPathComponent("ImagesFolder").absoluteString //Set folder name
print(dataPath)
//Check is folder available or not, if not create
if !FileManager.default.fileExists(atPath: dataPath) {
try? FileManager.default.createDirectory(atPath: dataPath, withIntermediateDirectories: true, attributes: nil) //Create folder if not
}
// create the destination file url to save your image
let fileURL = URL(fileURLWithPath:dataPath).appendingPathComponent("imageName.jpg")//Your image name
print(fileURL)
// get your UIImage jpeg data representation
let data = UIImageJPEGRepresentation(image!, 1.0)//Set image quality here
do {
// writes the image data to disk
try data?.write(to: fileURL, options: .atomic)
} catch {
print("error:", error)
}
}
}

Answer 7

Although the answers are correct, I want to share utility functions for this purpose. You can use the following 2 methods to save and Image in Documents Directory and then load an image from Documents Directory. Here you can find the Detailed Article.
public static func saveImageInDocumentDirectory(image: UIImage, fileName: String) -> URL? {
let documentsUrl = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!;
let fileURL = documentsUrl.appendingPathComponent(fileName)
if let imageData = UIImagePNGRepresentation(image) {
try? imageData.write(to: fileURL, options: .atomic)
return fileURL
}
return nil
}
public static func loadImageFromDocumentDirectory(fileName: String) -> UIImage? {
let documentsUrl = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!;
let fileURL = documentsUrl.appendingPathComponent(fileName)
do {
let imageData = try Data(contentsOf: fileURL)
return UIImage(data: imageData)
} catch {}
return nil
}

Answer 8

Answer for Swift 5.x
func saveImageToDocumentsDirectory() {
let directoryPath = try! FileManager().url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
let urlString : NSURL = directoryPath.appendingPathComponent("Image1.png") as NSURL
print("Image path : \(urlString)")
if !FileManager.default.fileExists(atPath: urlString.path!) {
do {
try self.image.jpegData(compressionQuality: 1.0)!.write(to: urlString as URL)
print ("Image Added Successfully")
} catch {
print ("Image Not added")
}
}
}
Note : image = your declared image.