Composition and attachments

Plain C# functions return reusable View declarations. children: new[] { ... } nests declarations inside the factory without creating native objects. Child arrays are copied. Visual/control/layout entries create children. Modifiers attach to the containing GameObject. P.Self(...) explicitly places a visual component on that same object.

View Button(Vector2 position, Value<string> text, Action onClick)
{
    return P.Button(
        anchoredPosition: position,
        sizeDelta: new Vector2(200, 150),
        onClick: onClick,
        children: new[]
        {
            P.Self(P.Image(color: new Color(50f / 255, 50f / 255, 50f / 255))),
            P.Outline(effectColor: Color.black),
            P.Text(
                text,
                color: Color.white,
                outlineColor: new Color32(0, 0, 0, 255),
                outlineWidth: .2f
            ),
        }
    );
}

The button object has RectTransform, Image, Button and Outline. Its text child has RectTransform, CanvasRenderer and TextMeshProUGUI. P.Image() without Self creates a child image. Nested factory calls apply the same placement rules at every level.

Unity permits one Graphic per GameObject. Pine rejects conflicting Graphics and component multiplicity forbidden by Unity; allowed repetitions such as multiple Outline components remain independent. A modifier/Self entry requires a containing visual view. Named children arrays keep the syntax valid in C# 9 alongside optional named settings. Use components: new[] { ... } for static modifiers or Self entries when children is a reactive getter.

With reactive children, name the optional settings: P.Button(text: "Save", children: () => rows.Value). The getter overload requires children; C# positional arguments follow that overload's parameter order.

TMP correction: the uGUI Outline/Shadow components affect standard uGUI meshes such as Image and LegacyText. For TMP text use its native outlineColor/outlineWidth or a font material preset. Attaching an Outline does not turn it into a TMP shader effect. TMP outline API.

For Unity callbacks, declare a concrete MonoBehaviour with a public View Create(...) method. Pine generates Components.Counter(...) with the same named parameters. Create runs once before Awake/OnEnable; hiding retains the instance, and destroying its UI disposes its behaviour and reactive scope. using Pine; opts a file into component generation. See the Composition sample for independent/shared state and multi-level nesting.