API reference

API overview

The engine's API has two sides: what you write inside a .dcue component, and what game code calls from outside. This page maps both to their namespaces.

Where to look

You want to	Page
Declare state, props, effects and lifecycle in a component	Component script
Write markup: expressions, directives, blocks	Template syntax
Show an app or a page, and reach it from a MonoBehaviour	Views and UiSystem
Change elements, set styles without allocating, find things by name	DOM, styles and queries
Handle pointer and keyboard events; send input from code	Events and input
Use signals and reactive collections directly	Reactivity
Read and switch texts	Locale
Register cameras, models, videos, materials, font packs	Unity content and fonts

Namespaces

Namespace	Main types
`DevCore.UiEngine.Unity.Hosting`	`DevCoreApp`, `DevCore3DView`, `AppView`, `UIView`, `UiSystem`, `UIRenderMode`, `UIScaleMode`, `FontFallbackSettings`, `UIStatsOverlay`
`DevCore.UiEngine.Unity.Elements`	`UnityElements`
`DevCore.UiEngine.View`	`DocumentView`, `ViewResources`, `ClientRect`, the `GetBoundingClientRect` and `ElementFromPoint` extensions
`DevCore.UiEngine.Dom`	`Document`, `Element`, `Node`, `Text`, `InlineStyle`
`DevCore.UiEngine.Dom.Events`	`Event`, `EventType`
`DevCore.UiEngine.Input`	`PointerEvent`, `KeyboardEvent`, `WheelEvent`, `FocusEvent`, `InputEvent`, `DocumentInput`, `PointerInput`, `NavigationDirection`, the pointer-capture extensions
`DevCore.UiEngine.Css.Properties`	`CssPropertyId`
`DevCore.UiEngine.Css.Values`	`CssUnit`, `Rgba`
`DevCore.UiEngine.Components`	`Component`, `ComponentRegistry`, `ContextKey<T>`
`DevCore.UiEngine.Reactivity`	`Reactive`, `Signal<T>`, `StateList<T>`, `StateDictionary<K, V>`, `ReactiveScope`
`DevCore.UiEngine.Localization`	`Locale`, `LocaleKey`, `LocaleTable`, `PluralRules`

Your game's own components are in the namespace of their folder: GameUI for Assets/DevCoreUIEngine/App, GameUI.Components for its Components folder.

Assembly references

The engine is split into assemblies named after its namespaces. An assembly definition that holds .dcue files, or game code that calls the engine, references the assemblies it uses: for example DevCore.UiEngine.Input for PointerEvent, DevCore.UiEngine.View for ElementFromPoint, DevCore.UiEngine.Css for CssPropertyId, and DevCore.UiEngine.Localization wherever there are components.

Conventions

Main thread. The engine runs on Unity's main thread; call it from there.
Batched. Changes mark things dirty. The page updates once per frame, after LateUpdate, however many values changed.
Allocation-free paths are marked. Typed style setters, name queries, Text.SetData and template expressions allocate nothing. String-based setters parse and allocate.
Events are pooled. An event object is valid only while its handler runs; copy what you need out of it.
Web names, C# casing. querySelector is QuerySelector, classList.toggle is ClassList.Toggle, clientX is ClientX.
Lengths are CSS pixels unless a unit is given.

A complete example

HudController.cs

using DevCore.UiEngine.Css.Properties;
using DevCore.UiEngine.Css.Values;
using DevCore.UiEngine.Dom;
using DevCore.UiEngine.Unity.Hosting;
using UnityEngine;

public class HudController : MonoBehaviour
{
    Element marker;

    void Start()
    {
        var app = DevCoreApp.Current;
        marker = app.Q("player-marker");                 // look up once, keep it
    }

    void Update()
    {
        Vector2 p = Minimap.PositionOf(transform);       // your game's code
        marker.Style.Set(CssPropertyId.Translate, p.x, p.y, CssUnit.Px);   // no restyle, no layout, no paint
    }
}