how to use writeToFile to save image in document directory?

Nishad Arora picture Nishad Arora · Sep 29, 2015 · Viewed 36.7k times · Source
// 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

Leo Dabus picture Leo Dabus · Sep 29, 2015

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

// get the documents directory url
let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
// 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:  1.0),
  !FileManager.default.fileExists(atPath: fileURL.path) {
    do {
        // writes the image data to disk
        try data.write(to: fileURL)
        print("file saved")
    } catch {
        print("error saving file:", error)
    }
}