Binding Elements

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Evergine allows to bind dependencies automatically across your components, services and sceneManagers.

For example, bindings allow a custom component to require that its Owner Entity has a Transform3D component, and set it to a property during the Attach phase (see the Lifecycle documents)

This binding feature gives to developers a lot of flexibility to interconnect components, services and scene managers, avoiding the tedious part to setup this dependencies in Evergine Studio or from code.

In Evergine, we define bindings using property attributes ([BindComponent] for example).

Note

All dependencies are not available until the Attach phase, if you try to access during in the constructor, OnLoaded() or OnDestroy() methods, the property value is goint to be null

In this section

There are four types of binding:

• Bind Components
• Bind Services
• Bind Entities
• Bind SceneManagers

Example

In the following example, the component will bind a service, a component an a scene manager.

public class MyComponent : Component
{
    [BindService]
    private AssetsService assetsService;

    [BindSceneManager]
    private RenderManager renderManager;

    [BindComponent]
    private Transform3D transform;

    private Material defaultMaterial;

    protected override Start()
    {
        // All values of bind attributes will be injected after the Attach phase...
        
        // Bind assetService
        this.defaultMaterial = this.assetsService.Load<Material>(EvergineContent.Materials.DefaultMaterial);
        
        // Bind SceneManagers
        this.RenderManager.DebugLines = true;
        
        // Bind Components
        this.transform.Position = Vector3.Zero;
    }

    // ... 
}

Bind Collections

If the [Bind] attribute is set on top of List<T> property, they will attempt to search a list of elements that elements that satisfy the dependency:

// Bind with the Transform component of the owner entity...
[BindComponent]
private Transform3D transform;

// Bind a list with all Camera3D components of the entire scene...
[BindComponent(source: BindComponentSource.Scene)]
private List<Camera3D> sceneCameras;