Force uppercase in Input Field without using onValueChange?

Question

I wish to restrict input fields entry to all caps. However,

   void Awake ()
   {
     inputField = GetComponent<InputField>();
     inputField.onValueChange.AddListener( delegate { Manage(); } );
   }

   void Manage ()
   {
     inputField.text = inputField.text.ToUpper();
     Debug.Log( "Test" );
   }

The problem obviously is an infinite loop.

What's the best way to restrict input entry in Unity3D UI InputField ?

Answer 1

I know this is an old question but I came across with it today for an answer, and I found an alternative that works just as well.

You can add an input verification function to the input field which replaces and/or eliminate characters on the go.

For the game I'm writing I needed names with only minuscule letters, numbers, space and dash. Also the alphanumeric verification didn't work reliable enough on latin-extended input, so I added this piece of code:

this goes to class variables:

 public InputField inputField;

this goes to start function:

  inputField.onValidateInput += delegate (string input, int charIndex, char addedChar) {
        return nameValidation(addedChar);
  };

and this is the addedChar function that does the control and modification on per character basis:

 private char nameValidation(char c)
 {
     if (c >= 'A' && c <= 'Z') {
         return (char)((int)c - 'A' + 'a');
     }
     else if ((c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || c == '_' || c == ' ') {
         return c;
     } else {
         return '\0';
     }
 }

no more onChange causing more change!

And here's an even simpler function to force uppercase...

 void Start()
 {
     your_input.onValidateInput += 
         delegate (string s, int i, char c) { return char.ToUpper(c); };
 }

And if you want ONLY letters:

 void Start()
 {
     your_input.onValidateInput += delegate (string s, int i, char c) { return char.ToUpper(c); };
 }
 
 char Val(char c)
 {
     c =  char.ToUpper(c);
     return char.IsLetter(c) ? c : '\0';
 }

Here's uppercase letters only, and a length limit:

     your_input.onValidateInput += delegate (string s, int i, char c)
     {
         if (s.Length >= 4) { return '\0'; }
         c = char.ToUpper(c);
         return char.IsLetter(c) ? c : '\0';
     };

(Alternately, don't forget the very handy .CharacterValidation approach. It is often all you need:)

 void Start()
 {
     your_input.characterValidation = InputField.CharacterValidation.Alphanumeric;
 }

So when using .onValidateInput the .Net "char." functions are very handy.

Answer 2

Answer by AeonIxion · May 04, 2015 at 12:39 PM

So the problem is that it keeps looping. You could save the inputfield.text into a variable and then compare it to inputField.text.ToUpper(). If it's the same, then don't do anything.

 string text = inputField.text;
 if(text != inputField.text.ToUpper())
 {
         inputField.text = inputField.text.ToUpper();
 }

I think this will work.

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Answer 3

Answer by thelackey3326 · Nov 04, 2015 at 06:30 PM

You can set a validation callback for the input field, and if the character is valid, return its uppercase form.

There is a full example fortunately in the Unity manual:

http://docs.unity3d.com/ScriptReference/UI.InputField-onValidateInput.html

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Force uppercase in Input Field without using onValueChange?

3 Replies

And here's an even simpler function to force uppercase...

Here's uppercase letters only, and a length limit:

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