Unable to save images in the right directory - swift

Question

I am trying to save images in a directory. Images are correctly saved in the right place, but when I inspect these with the path in the finder, all the images are damaged and unsable.
damaged images
Below the static method:
static func writeImageFile(with data: Data, issue: Issue, page: Int, isThumbnail: Bool) throws -> URL {
let url = MediaFileManager.issueImagesDirectoryURL(issue: issue).ensuringDirectoryExists()
let imageURL = url.appendingPathComponent(imageName(for: page, isThumbnail: isThumbnail))
try data.write(to: imageURL)
return url
}
And the call in the class:
DispatchQueue.main.async {
guard let data = result.data else {
self.downloadDidFail(for: result.page)
return
}
do {
let writeImageFile = try MediaFileManager.writeImageFile(with: data, issue: self.issue, page: result.page, isThumbnail: false)
let writeThumbFile = try MediaFileManager.writeImageFile(with: data, issue: self.issue, page: result.page, isThumbnail: true)
print(writeImageFile)
print(writeThumbFile)
} catch let error as NSError {
print(error.localizedDescription)
}
}

Answer 1

I will assume, since you don't quite specify this, that you have a bunch of UIImage objects.
And I also noticed that you want your images to be saved as JPEG, which is no trouble at all, don't worry.
I would go with something like this:
if let image = UIImage(named: "example.png") {
if let data = UIImageJPEGRepresentation(image, 1.0) {
let filename = getDocumentsDirectory().appendingPathComponent("copy.png")
try? data.write(to: filename)
}
}
Where the func getDocumentsDirectory() is the following:
func getDocumentsDirectory() -> URL {
let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
return paths[0]
}
You might wonder why I used 1.0 for the second parameter in UIImageJPEGRepresentation, well that's the JPEG quality mapped between 0.0 and 1.0 (it's a float).
If you have any details that I am not aware of, please reply and I will try to help accordingly.
Hope it helps you, cheers!
Source: link

Answer 2

Have you tried to load the image to a UIImageView to see if the images are being properly downloaded? imageView.image = UIImage(data: data).
But I also detect that you're saving Data instead of the image, in order to make sure that you're saving an image I would try the following
static func writeImageFile(with data: Data, issue: Issue, page: Int, isThumbnail: Bool) throws -> URL {
let url = MediaFileManager.issueImagesDirectoryURL(issue: issue).ensuringDirectoryExists()
let imageURL = url.appendingPathComponent(imageName(for: page, isThumbnail: isThumbnail))
let image = UIImage(data: data)
let imgData = UIImageJPEGRepresentation(image, 1)
try imgData.write(to: imageURL)
return url
}
Yes, it might have unnecessary steps, worth trying, this way we're making sure that it's saved as Jpeg. But again, I would check if the images are being properly downloaded first.