I'm just trying to display an image that is stored in the local filesystem, but the more I dig into this the more confused I get.
So previously I used this code (it's simplified):
func findImage(name: String) -> UIImage? {
do {
let url = try FileManager.default.url(for: .applicationSupportDirectory,
in: .userDomainMask,
appropriateFor: nil,
create: false)
.appendingPathComponent("MyFolder")
.appendingPathComponent("\(name).png")
guard let image = UIImage(contentsOfFile: url.path) else {
return nil
}
return image
} catch {
print(error.localizedDescription)
}
return nil
}
Notice I create the URL with just .appendingPathComponent() and turning URL to path via url.path.
It works! So what's the question?
In Improving performance and stability when accessing the file system I've read that you better use the new appendingPathComponent(_:isDirectory:), that's good, will do.
Also url.path is deprecated in iOS18. Should I use url.path(percentEncoded:) instead? What should be the value of percentEncoded when accessing the local filesystem?
In this adjacent thread I've read:
Don't use UIImage(contentsOfFile:) either, because it's a path-based API. There's no URL-based equivalent, which is an Apple clue that should be doing something else.
Is this true? Then how should I store and load my images?
Just FYI, I create images like this:
private func generateThumbnail(name: String) {
guard let drawingWidth = canvasGeo?.size.width,
let drawingHeight = canvasGeo?.size.height else { return }
let thumbnailRect = CGRect(x: 0, y: 0, width: drawingWidth, height: drawingHeight)
Task {
UITraitCollection(userInterfaceStyle: .light).performAsCurrent {
let image = self.canvasView.drawing.image(from: thumbnailRect, scale: UIScreen.main.scale)
guard let data = image.pngData() else { return } // -- HERE
do {
try FileManager.default.createDirectory(at: try FileManager.default.url(for: .applicationSupportDirectory,
in: .userDomainMask,
appropriateFor: nil,
create: true)
.appendingPathComponent("MyFolder"),
withIntermediateDirectories: true,
attributes: nil)
let filename = "\(name).png"
let url = try FileManager.default.url(for: .applicationSupportDirectory,
in: .userDomainMask,
appropriateFor: nil,
create: true)
.appendingPathComponent("MyFolder")
.appendingPathComponent(filename)
try data.write(to: url, options: .atomic) // -- and HERE
} catch {
print(error.localizedDescription)
}
}
}
}
My usecase — just save the user's PencilKit Canvas as an image and display it back to him on a different View. I'm on SwiftUI and iOS 16+.
Would be happy to learn the correct way, thanks!
