UxmlAttributeConverter<T0>

Description

Converts a UxmlAttribute type to and from a string.

Fields marked with UxmlAttributeAttribute are represented in UXML by a single string attribute, however, to properly serialize these attributes, you must declare a UxmlAttributeConverter. This converter converts the string attribute value into the appropriate data type for the marked field.

Note: The following types have native support and you can use them without declaring a UxmlAttributeConverter:

• bool
• char
• string
• short
• int
• long
• Enum
• float
• double
• Type(Additional resources: UxmlTypeReferenceAttribute)
• Color
• Hash128
• Length
• Bounds
• BoundsInt
• Rect
• RectInt
• Vector2
• Vector2Int
• Vector3
• Vector3Int
• Vector4

The following example creates a custom control that uses a class instance and a list of class instances as its attributes.

using System;
using System.Collections.Generic;
using UnityEngine.UIElements;

[Serializable]
public class MyClassWithData
{
    public int myInt;
    public float myFloat;
}

[UxmlElement]
public partial class MyElementWithData : VisualElement
{
    [UxmlAttribute]
    public MyClassWithData someData;

    [UxmlAttribute]
    public List<MyClassWithData> lotsOfData;
}

To support the class, declare a converter:

using UnityEditor.UIElements;

public class MyClassWithDataConverter : UxmlAttributeConverter<MyClassWithData>
{
    public override MyClassWithData FromString(string value)
    {
        // Split using a | so that comma (,) can be used by the list.
        var split = value.Split('|');

        return new MyClassWithData
        {
            myInt = int.Parse(split[0]),
            myFloat = float.Parse(split[1])
        };
    }

    public override string ToString(MyClassWithData value) => $"{value.myInt}|{value.myFloat}";
}

Example UXML:

<ui:UXML xmlns:ui="UnityEngine.UIElements">
    <MyElementWithData some-data="1|2.3" lots-of-data="1|2,3|4,5|6" />
</ui:UXML>

Public Methods