Runtime data binding through custom class with value and bindings

Unity Engine
, , ,
1

Hello. Could you please help me figure out what I’m doing wrong?

Previously, in my PressureData class, I defined Speed like this:

[SerializeField] private int speed;
[CreateProperty] public int Speed
{
    get => speed;
    set
    {
        speed = value;
        speedBinding?.MarkDirty();
    }
}
private DataBinding speedBinding;
public DataBinding SpeedBinding => speedBinding ??= new DataBinding {
    dataSourcePath = new PropertyPath(nameof(Speed)),
    updateTrigger = BindingUpdateTrigger.OnSourceChanged,
    bindingMode = BindingMode.ToTarget,
};

And the binding in the necessary VisualElement worked like this:

dataSource = pressureData = _pressureData;
SetBinding(nameof(Speed), pressureData.SpeedBinding);

Everything worked in the binding, and the interface updated correctly.

Now, I’ve added a class:

[Serializable]
public class BindableProperty<T>
{
    [SerializeField] public T value;
    [SerializeField] private BindingUpdateTrigger updateTrigger;
    [SerializeField] private BindingMode bindingMode;

    public string PropertyName { get; }

    [CreateProperty] public T Value
    {
        get => value;
        set
        {
            this.value = value;
            binding?.MarkDirty();
        }
    }

    private DataBinding binding;
    public DataBinding Binding => binding ??= new DataBinding
    {
        dataSourcePath = new PropertyPath($"{PropertyName}.Value"),
        updateTrigger = updateTrigger,
        bindingMode = bindingMode,
    };

    public BindableProperty(T initialValue, string propertyName, BindingUpdateTrigger updateTrigger = BindingUpdateTrigger.WhenDirty, BindingMode bindingMode = BindingMode.ToTarget)
    {
        value = initialValue;
        PropertyName = propertyName;
        this.updateTrigger = updateTrigger;
        this.bindingMode = bindingMode;
    }
}

And in PressureData, I defined it like this:

[CreateProperty] public BindableProperty<int> Speed = new BindableProperty<int>(0, "Speed", BindingUpdateTrigger.OnSourceChanged);

The binding is now:

SetBinding(nameof(Speed), pressureData.Speed.Binding);

But now the interface does not update as expected. What am I doing wrong?

2

Which version of the editor are you using? I’ve tried it locally and it seemed to work fine. I’ve used an IntegerField, binding to the value property using:

field.SetBinding("value", dataSource.Speed.Binding);
3

I’m using Unity 6000.0.25.

In my example, Speed in the custom element is an int property, which then gets assigned to a Label in the set. I pass pressureData as the dataSource to this custom element, where Speed and other bindable properties are stored.

Could you show me how you set everything up to make it work?

4

Sure, I’ve rigged it using this MonoBehaviour:

using UnityEngine;
using UnityEngine.UIElements;

public class MyBehaviour : MonoBehaviour
{
    private void OnEnable()
    {
        var document = GetComponent<UIDocument>();
        if (document.rootVisualElement == null)
            return;

        var root = document.rootVisualElement;
        var field = root.Q<IntegerField>();

        var dataSource = (DataSource)field.dataSource;
        field.SetBinding("value", dataSource.Speed.Binding);
    }
}

And this as the data source:

using Unity.Properties;
using UnityEngine;
using UnityEngine.UIElements;

[CreateAssetMenu(fileName = "DataSource", menuName = "Data Source", order = 0)]
public class DataSource : ScriptableObject
{
    [CreateProperty]
    public BindableProperty<int> Speed = new BindableProperty<int>(0, nameof(Speed), BindingUpdateTrigger.OnSourceChanged);
}

And the UXML file:

<engine:UXML
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:engine="UnityEngine.UIElements"
        noNamespaceSchemaLocation="../UIElementsSchema/UIElements.xsd">
    <engine:IntegerField
            label="Integer Field"
            value="42"
            data-source="project://database/Assets/DataSource.asset?fileID=11400000&amp;guid=6fa9dca141170da4296a2915482a6352&amp;type=2#DataSource" />
</engine:UXML>
5

Let me send you the complete setup shortly; I’ll send it to you in a private message.

6

Hello. I’ve sent you my entire setup in a private message.