Swiftui - Access UIKit methods/properties from UIViewRepresentable - swiftui

Question

I have created a SwiftUI TextView based on a UITextView using UIViewRepresentable (s. code below). Displaying text in Swiftui works OK.
But now I need to access internal functions of UITextView from my model. How do I call e.g. UITextView.scrollRangeToVisible(_:) or access properties like UITextView.isEditable ?
My model needs to do these modifications based on internal model states.
Any ideas ? Thanks
(p.s. I am aware of TextEditor in SwiftUI, but I need support for iOS 13!)
struct TextView: UIViewRepresentable {
#ObservedObject var config: ConfigModel = .shared
#Binding var text: String
#State var isEditable: Bool
var borderColor: UIColor
var borderWidth: CGFloat
func makeCoordinator() -> Coordinator {
Coordinator(self)
}
func makeUIView(context: Context) -> UITextView {
let myTextView = UITextView()
myTextView.delegate = context.coordinator
myTextView.isScrollEnabled = true
myTextView.isEditable = isEditable
myTextView.isUserInteractionEnabled = true
myTextView.layer.borderColor = borderColor.cgColor
myTextView.layer.borderWidth = borderWidth
myTextView.layer.cornerRadius = 8
return myTextView
}
func updateUIView(_ uiView: UITextView, context: Context) {
uiView.font = uiView.font?.withSize(CGFloat(config.textsize))
uiView.text = text
}
class Coordinator : NSObject, UITextViewDelegate {
var parent: TextView
init(_ uiTextView: TextView) {
self.parent = uiTextView
}
func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
return true
}
func textViewDidChange(_ textView: UITextView) {
self.parent.text = textView.text
}
}
}

Answer 1

You can use something like configurator callback pattern, like
struct TextView: UIViewRepresentable {
#ObservedObject var config: ConfigModel = .shared
#Binding var text: String
#State var isEditable: Bool
var borderColor: UIColor
var borderWidth: CGFloat
var configurator: ((UITextView) -> ())? // << here !!
func makeCoordinator() -> Coordinator {
Coordinator(self)
}
func makeUIView(context: Context) -> UITextView {
let myTextView = UITextView()
myTextView.delegate = context.coordinator
myTextView.isScrollEnabled = true
myTextView.isEditable = isEditable
myTextView.isUserInteractionEnabled = true
myTextView.layer.borderColor = borderColor.cgColor
myTextView.layer.borderWidth = borderWidth
myTextView.layer.cornerRadius = 8
return myTextView
}
func updateUIView(_ uiView: UITextView, context: Context) {
uiView.font = uiView.font?.withSize(CGFloat(config.textsize))
uiView.text = text
// alternat is to call this function in makeUIView, which is called once,
// and the store externally to send methods directly.
configurator?(myTextView) // << here !!
}
// ... other code
}
and use it in your SwiftUI view like
TextView(...) { uiText in
uiText.isEditing = some
}
Note: depending on your scenarios it might be additional conditions need to avoid update cycling, not sure.