Question TypedUxmlAttributeDescription<TimeSpan>

I would like to create a

TimeSpanField

. I've been trying to stay inline with Unity's practices and want to write a

UxmlTimeSpanAttributeDescription

to compliment it.

Code (CSharp):

1. using System;
2. using UnityEngine.UIElements;
3.  
4. namespace UnityClock.UIElements
5. {
6.     public class TimeSpanField : BaseField<TimeSpan>
7.     {
8.         public new class UxmlFactory : UxmlFactory<TimeSpanField, UxmlTraits> { }
9.  
10.         public new class UxmlTraits : BaseFieldTraits<TimeSpan, UxmlTimeSpanAttributeDescription> { }
11.  
12.         public TimeSpanField() : this(null) { }
13.  
14.         public TimeSpanField(string label) : base(label, new Label()) { }
15.     }
16. }
17.  

Code (CSharp):

1. using System;
2. using UnityEngine.UIElements;
3.  
4. namespace UnityClock.UIElements
5. {
6.     //
7.     // Summary:
8.     //     Describes a UXML TimeSpan attribute.
9.     public class UxmlTimeSpanAttributeDescription : TypedUxmlAttributeDescription<TimeSpan>
10.     {
11.         //
12.         // Summary:
13.         //     The default value for the attribute, as a string.
14.         public override string defaultValueAsString => base.defaultValue.ToString();
15.  
16.         //
17.         // Summary:
18.         //     Constructor.
19.         public UxmlTimeSpanAttributeDescription ()
20.         {
21.             base.type = "System.TimeSpan";
22.             base.typeNamespace = "http://www.w3.org/2001/XMLSchema";
23.             base.defaultValue = TimeSpan.Zero;
24.         }
25.  
26.         //
27.         // Summary:
28.         //     Retrieves the value of this attribute from the attribute bag. Returns the value
29.         //     if found; otherwise, it returns defaultValue.
30.         //
31.         // Parameters:
32.         //   bag:
33.         //     The bag of attributes.
34.         //
35.         //   cc:
36.         //     The context in which the values are retrieved.
37.         //
38.         // Returns:
39.         //     The value of the attribute.
40.         public override TimeSpan GetValueFromBag(IUxmlAttributes bag, CreationContext cc)
41.         {
42.             return GetValueFromBag(bag, cc, (string s, TimeSpan t) => ConvertValueToTimeSpan(s, t), base.defaultValue);
43.         }
44.  
45.         public bool TryGetValueFromBag(IUxmlAttributes bag, CreationContext cc, ref TimeSpan value)
46.         {
47.             return TryGetValueFromBag(bag, cc, (string s, TimeSpan t) => ConvertValueToTimeSpan(s, t), base.defaultValue, ref value);
48.         }
49.  
50.         private static TimeSpan ConvertValueToTimeSpan(string v, TimeSpan defaultValue)
51.         {
52.             if (v == null || !TimeSpan.TryParse(v, out var result))
53.             {
54.                 return defaultValue;
55.             }
56.  
57.             return result;
58.         }
59.     }
60. }
61.  

This code runs fine, however my attribute doesn't show up in the UIBuilder.

vs where

ExampleField

uses a double, otherwise it is the same as

TimeSpanField

.

Normally I would write this off as "TimeSpan can't be serialized" but I thought that AttributeDescriptions are always strings, and use defaultValueAsString and GetValueFromBag to convert between the two.

I summon thee, @uDamian



If

UxmlTimeSpanAttributeDescription

is not possible, what is my best course of action? My assumption is I will have to inherit from e.g.

BaseFieldTraits<string, UxmlStringAttributeDescription>

with a custom

override Init

instead, but I've had some conversion errors there, don't exactly know why.

 

Unrelated, but you guys wrote some killer documentation, it was really clear how to pick up creating custom controls!

 

Hi 1606917[/URL]]@uDamian wanted to do a quick plug before I try implementing a different solution on Tuesday. I’d rather not go there, because that solution is a lot more icky than I’d like, but sometimes we have to make weird solutions to solve weird problems.

 

Hey so I noticed that in 2023.2 there is an amazing class for this that does exactly what I want.

https://docs.unity3d.com/2023.2/Doc...ence/UIElements.UxmlAttributeConverter_1.html

Scared to ask... but there's no chance this will be backported will it?