Delegate Binders

Delegate binders create bindings from code without a MonoBehaviour.

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Overview

Delegate binders take delegates (Action, Func) and build a binding programmatically. Use them when a custom binder is needed without a dedicated class.

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DelegateOneWayBinder<T>

The simplest binder: takes an Action<T> that applies the value:

var binder = new DelegateOneWayBinder<string>(value =>
{
    Debug.Log($"Name changed: {value}");
});

view.BindCustomBinder("Name", binder);

With a target: DelegateOneWayBinder<TTarget, T>

var label = GetComponent<TMP_Text>();
var binder = new DelegateOneWayBinder<TMP_Text, string>(
    label,
    (target, value) => target.text = value
);

Modes: OneWay, OneTime (TwoWay is not allowed).

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DelegateTwoWayBinder<T>

A two-way binder: takes an Action<T> to apply the value and reports changes through ValueChanged:

var binder = new DelegateTwoWayBinder<string>(
    subscribe: callback =>
    {
        // Subscribe to UI changes → call callback(newValue)
        inputField.onEndEdit.AddListener(text => callback(text));
    },
    setValue: value =>
    {
        inputField.text = value;
    }
);

Extra parameters:

• getValueOnBound: called on bind, returns the initial value
• getValueOnUnbinding: called on unbind

Mode: TwoWay.

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DelegateOneWayToSourceBinder<T>

A reverse binder: sends values from the View to the ViewModel:

var binder = new DelegateOneWayToSourceBinder<float>(
    subscribe: callback =>
    {
        slider.onValueChanged.AddListener(v => callback(v));
    },
    getValueOnBound: () => slider.value  // initial value
);

Mode: OneWayToSource.

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CasterBinder<TFrom, TTo>

A binder with a type conversion through IConverter<TFrom, TTo>:

var binder = new CasterBinder<int, string>(
    setValue: text => label.text = text,
    converter: new IntToStringConverter()
);

Modes: OneWay, OneTime.

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DelegateOneTimeBinder<T>

A binder that receives the value once:

var binder = new DelegateOneTimeBinder<Config>(config =>
{
    ApplyConfig(config);
});

Mode: OneTime.

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When to use

Case	Binder
A simple reaction to a change	DelegateOneWayBinder<T>
Two-way link with a custom component	DelegateTwoWayBinder<T>
Passing data from the UI to the ViewModel	DelegateOneWayToSourceBinder<T>
Type conversion while binding	CasterBinder<TFrom, TTo>
One-off initialization	DelegateOneTimeBinder<T>

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See also

• Value Binders, holding the bound value
• Binders, the binder system overview
• StarterKit overview