/// <summary>
/// Constructs an instance of <see cref="ComponentState"/>.
/// </summary>
/// <param name="renderer">The <see cref="Renderer"/> with which the new instance should be associated.</param>
/// <param name="componentId">The externally visible identifier for the <see cref="IComponent"/>. The identifier must be unique in the context of the <see cref="Renderer"/>.</param>
/// <param name="component">The <see cref="IComponent"/> whose state is being tracked.</param>
/// <param name="parentComponentState">The <see cref="ComponentState"/> for the parent component, or null if this is a root component.</param>
public ComponentState(Renderer renderer, int componentId, IComponent component, ComponentState parentComponentState)
{
ComponentId = componentId;
ParentComponentState = parentComponentState;
Component = component ?? throw new ArgumentNullException(nameof(component));
_renderer = renderer ?? throw new ArgumentNullException(nameof(renderer));
_cascadingParameters = CascadingParameterState.FindCascadingParameters(this);
CurrentRenderTree = new RenderTreeBuilder();
_renderTreeBuilderPrevious = new RenderTreeBuilder();
if (_cascadingParameters.Count != 0)
{
_hasCascadingParameters = true;
_hasAnyCascadingParameterSubscriptions = AddCascadingParameterSubscriptions();
}
}
public static void InitializingComponent(ILogger logger, ComponentState componentState, ComponentState parentComponentState)
{
if (logger.IsEnabled(LogLevel.Debug)) // This is almost always false, so skip the evaluations
{
if (parentComponentState == null)
{
_initializingRootComponent(logger, componentState.ComponentId, componentState.Component.GetType(), null);
}
else
{
_initializingChildComponent(logger, componentState.ComponentId, componentState.Component.GetType(), parentComponentState.ComponentId, parentComponentState.Component.GetType(), null);
}
}
}