BlazorOpenApi/BlazorOpenApi/Controls/TocMember.razor

@if (string.IsNullOrWhiteSpace(Anchor))
{
    <CascadingValue Name="OpenAPIUI_TOC_Parent" Value="@_anchor">
        <div id="@_anchor">
            @if (ChildContent != null)
            {
                @ChildContent
            }
        </div>
    </CascadingValue>
}
else
{
    <CascadingValue Name="OpenAPIUI_TOC_Parent" Value="@Anchor">
        <div>
            @if (ChildContent != null)
            {
                @ChildContent
            }
        </div>
    </CascadingValue>
}


@code{
    [Parameter] public string Title     { get; set; } = "";
    [Parameter] public string Anchor    { get; set; } = "";
    [Parameter] public bool   Collapsed { get; set; }

    [Parameter] public RenderFragment? ChildContent { get; set; }

    [CascadingParameter(Name = "OpenAPIUI_TOC")]        public ITableOfContentsTree Tree   { get; set; } = null!;
    [CascadingParameter(Name = "OpenAPIUI_TOC_Parent")] public string               Parent { get; set; } = "";

    private string _anchor = $"anc{Random.Shared.Next():X8}";

    protected override void OnAfterRender(bool firstRender)
    {
        if (!firstRender)
            return;

        Tree.Add(Title, string.IsNullOrWhiteSpace(Anchor) ? _anchor : Anchor, Parent, Collapsed);
    }

}