indices(in:)

Declaration

func indices(in text: AttributedString) -> AttributedTextSelection.Indices

Return Value

The current selection if valid for the given text or a valid fallback index otherwise.

Discussion

Always make sure to keep selection and text synchronized. Use Foundation/AttributedString/transform(updating:body:), Foundation/AttributedString/transformAttributes(in:body:) or Foundation/AttributedString/replaceSelection(_:with:) to do so automatically.

Reset your selection manually to a newly initialized one after making programmatic changes to the text where the selection should not just move with the characters.

struct ContentView: View {
    @State private var text = AttributedString()
    @State private var selection = AttributedTextSelection()

    var body: some View {
        TextEditor(text: $text, selection: $selection)

        Button("Insert Date") {
            text.replaceSelection(
                &selection,
                withCharacters: Date.now.formatted())
        }

        Button("Reset") {
            text = "Hello, World!"
            selection = .init(range: text.startIndex..<text.endIndex)
        }
    }
}

For more details on attributed string index validity, see isValid(within:).