Author Blazor Component

Core Rules

• Data flows down via [Parameter]. Events flow up via EventCallback<T> (never Action/Func).
• Never mutate [Parameter] properties. Copy to a private field in OnParametersSet.
• Use [Parameter] public T Prop { get; set; } — never required or init (causes BL0007).
• Use [EditorRequired] for required parameters.
• Handle all states: loading, empty, loaded, error — each with @if/@else.
• Use @key on repeated elements in loops for efficient diffing.
• Use IReadOnlyList<T> (not IEnumerable<T>) for collection parameters.

RenderFragment & Generics

[Parameter] public RenderFragment? ChildContent { get; set; }
[Parameter] public RenderFragment<TItem>? RowTemplate { get; set; }  // generic template