SwiftUI 2.0: export group of images with .fileExporter modifier - swiftui

Question

This is a follow up on this thread:
SwiftUI 2.0: export images with .fileExporter modifier
Goal: export a group of images in SwiftUI
What I did:
I am using the .fileExporter modifier, with the FileDocument struct.
Also open to other approach, like . fileMover modifier for example.
Problem:
When setting the FileDocument for multiple images struct I am getting am error on func fileWrapper (check code bellow).
Question:
How can I export multiple images in SwiftUI (could be any method)?
//file exporter
.fileExporter(isPresented: $exportFile, document: ImageDocument(
image: UIImage(data: product.cover ?? Data())!,
image2: UIImage(data: product.cover2 ?? Data())!)
,
contentType: .jpeg, onCompletion: { (result) in
if case .success = result {
print("Success")
} else {
print("Failure")
}
})
//export group of images
struct ImageDocument: FileDocument {
static var readableContentTypes: [UTType] { [.jpeg] }
var image: UIImage
var image2: UIImage
init(
image: UIImage?,
image2: UIImage?
) {
self.image = image ?? UIImage()
self.image2 = image2 ?? UIImage()
}
init(configuration: ReadConfiguration) throws {
guard let data = configuration.file.regularFileContents,
let image = UIImage(data: data),
let image2 = UIImage(data: data)
else {
throw CocoaError(.fileReadCorruptFile)
}
self.image = image
self.image2 = image2
}
func fileWrapper(configuration: WriteConfiguration) throws -> FileWrapper {
return FileWrapper(regularFileWithContents:
image.jpegData(compressionQuality: 0.80)!,
image2.jpegData(compressionQuality: 0.80)!//<----- getting an "extra argument error here
)
}
}
Update:
Tried to rewrite Max answer to UIImage, but this only exports 1 image:
import SwiftUI
class AppContext: ObservableObject {
#Published var fileSaveDialogShown = false
}
#main
struct FocalApp: App {
#StateObject var appContext = AppContext()
var body: some Scene {
WindowGroup {
ContentView()
.environmentObject(self.appContext)
.fileExporter(
isPresented: $appContext.fileSaveDialogShown,
documents: [
ImageDocument(image: UIImage(named: "1")),
ImageDocument(image: UIImage(named: "2"))
],
contentType: .jpeg // Match this to your representation in ImageDocument
) { url in
print("Saved to", url) // [URL]
}
}
}
}
import SwiftUI
import UniformTypeIdentifiers
struct ImageDocument: FileDocument {
static var readableContentTypes: [UTType] { [.jpeg, .png, .tiff] }
var image: UIImage
init(image: UIImage?) {
self.image = image ?? UIImage()
}
init(configuration: ReadConfiguration) throws {
guard let data = configuration.file.regularFileContents,
let image = UIImage(data: data)
else {
throw CocoaError(.fileReadCorruptFile)
}
self.image = image
}
func fileWrapper(configuration: WriteConfiguration) throws -> FileWrapper {
// You can replace tiff representation with what you want to export
return FileWrapper(regularFileWithContents: image.jpegData(compressionQuality: 1)!)
}
}
struct ContentView: View {
#EnvironmentObject var appContext: AppContext
var body: some View {
VStack {
Button(action: {
appContext.fileSaveDialogShown.toggle()
}, label: {
Text("Button")
})
}
.frame(width: 200, height: 200)
}
}

Answer 1

You need to use fileExporter with documents instead of document, which takes in a Collection
Here's how I'm doing it on macOS, adapting it should be straightforward:
import SwiftUI
import UniformTypeIdentifiers
struct ImageDocument: FileDocument {
static var readableContentTypes: [UTType] { [.jpeg, .png, .tiff] }
var image: NSImage
init(image: NSImage?) {
self.image = image ?? NSImage()
}
init(configuration: ReadConfiguration) throws {
guard let data = configuration.file.regularFileContents,
let image = NSImage(data: data)
else {
throw CocoaError(.fileReadCorruptFile)
}
self.image = image
}
func fileWrapper(configuration: WriteConfiguration) throws -> FileWrapper {
// You can replace tiff representation with what you want to export
return FileWrapper(regularFileWithContents: image.tiffRepresentation!)
}
}
#main
struct FocalApp: App {
#StateObject var appContext = AppContext()
var body: some Scene {
WindowGroup {
MainView()
.environmentObject(self.appContext)
.fileExporter(
isPresented: $appContext.fileSaveDialogShown,
documents: [
ImageDocument(image: NSImage(named: "testimage1")),
ImageDocument(image: NSImage(named: "testimage2"))
],
contentType: .tiff // Match this to your representation in ImageDocument
) { url in
print("Saved to", url) // [URL]
}
}
}
}