SwiftUI TextField max length

Question

Is it possible to set a maximum length for TextField? I was thinking of handling it using onEditingChanged event but it is only called when the user begins/finishes editing and not called while user is typing. I've also read the docs but haven't found anything yet. Is there any workaround?

TextField($text, placeholder: Text("Username"), onEditingChanged: { _ in   print(self.$text) }) {   print("Finished editing") } 

Answer 1

You can do it with Combine in a simple way.

Like so:

import SwiftUI import Combine  struct ContentView: View {      @State var username = ""      let textLimit = 10 //Your limit          var body: some View {         //Your TextField         TextField("Username", text: $username)         .onReceive(Just(username)) { _ in limitText(textLimit) }     }      //Function to keep text length in limits     func limitText(_ upper: Int) {         if username.count > upper {             username = String(username.prefix(upper))         }     } } 

Answer 2

A slightly shorter version of Paulw11's answer would be:

class TextBindingManager: ObservableObject {     @Published var text = "" {         didSet {             if text.count > characterLimit && oldValue.count <= characterLimit {                 text = oldValue             }         }     }     let characterLimit: Int      init(limit: Int = 5){         characterLimit = limit     } }  struct ContentView: View {     @ObservedObject var textBindingManager = TextBindingManager(limit: 5)          var body: some View {         TextField("Placeholder", text: $textBindingManager.text)     } } 

All you need is an ObservableObject wrapper for the TextField string. Think of it as an interpreter that gets notified every time there's a change and is able to send modifications back to the TextField. However, there's no need to create the PassthroughSubject, using the @Published modifier will have the same result, in less code.

One mention, you need to use didSet, and not willSet or you can end up in a recursive loop.