init(_:for:contentType:prepareDocument:)

Declaration

init<D>(_ label: Text? = nil, for documentType: D.Type = D.self, contentType: UTType? = nil, prepareDocument: @escaping () async throws -> D? = { nil }) where D : FileDocument

Parameters

• label:

  A label for the button.

• documentType:

  A type of the document to create.

• contentType:

  An optional content type of the document to create.

• prepareDocument:

  A closure is called when a user presses the button. At this point, you can present a document template picker or another UI that allows users to choose a theme, configuration, or a template to create a document from. Return a prepared document, or throw an error if document creation failed. Return nil to request creation of an empty document.

Discussion

This initializer allows presenting a template picker, where a document can be prepopulated or preconfigured using a template.

@State private var isTemplatePickerPresented = false
@State private var documentCreationContinuation:
    CheckedContinuation<TextDocument?, any Error>?

var body: some Scene {
    DocumentGroupLaunchScene("My Documents") {
        NewDocumentButton(Text("Start Writing…"))
        NewDocumentButton(Text("Choose a Template"), for: TextDocument.self) {
            try await withCheckedThrowingContinuation { continuation in
                documentCreationContinuation = continuation
                isTemplatePickerPresented = true
            }
        }
        .fullScreenCover(isPresented: $isTemplatePickerPresented) {
            TemplatePicker(
                continuation: $documentCreationContinuation
            )
        }
    }

    DocumentGroup(newDocument: TextDocument()) { configuration in
        MyDocumentView(document: configuration.$document))
    }
}

struct TemplatePicker: View {
    @Binding var continuation:
        CheckedContinuation<TextDocument?, any Error>?
        @Environment(\.dismiss) var dismiss

    var body: some View {
        VStack {
            Text("Choose a template")
                .font(.title)
            Button("Meeting minutes") {
                let document = makeMeetingMinutes()
                documentCreationContinuation?.resume(returning: document)
                dismiss()
            }
            Button("Letter") {
                let document = makeLetter()
                documentCreationContinuation?.resume(returning: document)
                dismiss()
            }
            Button("Cancel") {
                documentCreationContinuation?.resume(throwing: CancellationError())
                dismiss()
            }
        }
    }

    private func makeMeetingMinutes() -> TextDocument { ... }
    private func makeLetter() -> TextDocument { ... }
}

struct TextDocument: FileDocument { ... }