TMP_InputValidation documentation

I can't find any info anywhere about how to actually implement the "Validate()" method of TMP_InputValidator.

https://docs.unity3d.com/Packages/com.unity.textmeshpro@1.1/api/TMPro.TMP_InputValidator.html

I created this class, but I don't know what to do with the input parameters "text" and "pos", and what to return if the character isn't valid?

Code (CSharp):

1.     public class BandNameInputValidator : TMP_InputValidator
2.     {
3.         public TextAsset validCharacters;
4.  
5.         public override char Validate(ref string text, ref int pos, char ch)
6.         {
7.            
8.         }
9.     }

 

This is what I ultimately decided to try, and I have confirmed that it's getting called, but even valid characters aren't showing up in my input field.

Code (CSharp):

1.     [CreateAssetMenu(menuName = "Gilligames/TMPro Validators/Band Name")]
2.     public class BandNameInputValidator : TMP_InputValidator
3.     {
4.         public TextAsset validCharacters;
5.  
6.         public override char Validate(ref string text, ref int pos, char ch)
7.         {
8.             if (validCharacters.text.IndexOf(ch) > -1)
9.             {
10.                 return ch;
11.             }
12.  
13.             return '\0';
14.         }
15.     }

 

The input value "text" is always empty string, which is why nothing is showing up in the input field.

 

Here is a revised example custom validator.

Code (csharp):

1.  
2. using UnityEngine;
3. using System;
4. namespace TMPro
5. {
6.     /// <summary>
7.     /// EXample of a Custom Character Input Validator to only allow digits from 0 to 9.
8.     /// </summary>
9.     [Serializable]
10.     [CreateAssetMenu(fileName = "InputValidator - Digits.asset", menuName = "TextMeshPro/Input Validators/Digits", order = 100)]
11.     public class TMP_DigitValidator : TMP_InputValidator
12.     {
13.         // Custom text input validation function
14.         public override char Validate(ref string text, ref int pos, char ch)
15.         {
16.             if (ch >= '0' && ch <= '9')
17.             {
18.                 text += ch;
19.                 pos += 1;
20.                 return ch;
21.             }
22.             return (char)0;
23.         }
24.     }
25. }
26.  

The line text += ch; was missing.

The custom validator gets the ref text in order to populate / manipulate it.

P.S. This feature is / was experimental. However, we can certainly evolve it as you work on this.

 

Thanks for the reply, Stephan. It would be immensely helpful to have that information in the documentation page that I linked to above, if possible.

 

You may have noticed in my code above that I am linking to a TextAsset that contains all the valid characters for the input field. I think it would be nice if TextMeshPro had a standard validation option that simply lets you link a TextAsset to the inspector, and it only allows input of the characters found in the text asset. This would be extremely flexible and re-usable without the need to create a new validator just to specify certain valid characters.

I use the same TextAsset to define fonts as I do for the validation of input fields, since I then know that only characters included in the font will be allowed for input.

 

Seems like that would be useful functionality. I'll take a look at this when I have time.

 

A couple of things:
This example doesn't account for the fact that a character may be inserted into the text

Appending with:

Code (csharp):

1. text += ch;

Needs to be changed to something like:

Code (csharp):

1. text = text.Insert(pos, ch.ToString());

Second, while the above fixes insertion of text, when some text is highlighted and you press a character, the selection is not cleared, but instead the new character is inserted at the beginning of the selection.If the entire string is highlighted, the character is added to the end. As far as I've been able to figure out, there's no way to properly support text selection replacement if you are using a custom validator because there is no way to access the information about what is currently selected.

Tested in 1.5.0 preview 4.

 

Hi,
could you please add this to the Unity Manual and Scripting reference, please?
Thanks!

 

Please find attached a version which allows writing a decimal point or comma (e.g. used in germany):

Code (CSharp):

1.         public override char Validate(ref string text, ref int pos, char ch)
2.         {
3.             //Allow handling . or , for float input
4.             bool ok = false;
5.             if (char.IsNumber(ch)) {
6.                 text = text.Insert(pos, ch.ToString());
7.                 ok = true;
8.             } else {
9.                 if ((ch == '.') || (ch == ',')) {
10.                     ok = (!text.Contains(".")) && (!text.Contains(","));
11.                     if (ok) {
12.                         text = text.Insert(pos, ch.ToString());
13.                     }
14.                 }
15.             }
16.  
17.             if (ok) {
18.                 pos++;
19.                 return (ch);
20.             } else {
21.                 return '\0';
22.             }
23.         }  

 

Could you please add this example to the manual and scripting page? It is sorely missing example code (as well as parameter and return value description)!

 

Stephan, could you please address the reply that guavaman made above? I came here to write the exact same thing just now. Thanks.

 

I'll try taking a look later today.

 

The documentation still misses this information more than two years after and for the latest version.

 

Bump!

I came here because the Regex validator (built-in) doesn't allow me to use backslashes it seems.. at least it breaks when I do, and then starts allowing no characters whatsoever.

I wanted a (sort of) simple Regex pattern,
\(?[0-9\.]*,\s*[0-9\.]*\)?

Looks complicated, but I just want to support latitude longitude coordinates, which could be written out like this (and these match the pattern given above):
(40.4, -78)
39.5, -80.1
(37,-83)

So I looked up how to make a custom validator, and well.. it seems the docs are still missing this info?

 

Nothing is ever being done. Forget about it.

 

@Stephan_B Better later than never. Also consider the automatic TMP validation based on the text atlas asset, this is a must-have feature.

Edit: Just noticed the Regex validation feature under the Input Field -> Content Type -> Character Validation...Not sure how i missed that the first time and jumped to the custom validator

 

So true....

Yeah, I just stopped using Unity and started making my own cross-platform C++/C# game engine since Sep 13, 2023.
Even with the challenges, for me, it's so much better.