PreviewDraftContentAreaRenderer.cs

public class PreviewDraftContentAreaRenderer(IContextModeResolver contextModeResolver, IHttpContextAccessor httpContextAccessor) : ContentAreaRenderer
{
    // Treat Preview like Edit so renderer doesn't skip edit-time behavior
    private bool IsDraftView
    {
     get
     {
         var ctx = httpContextAccessor.HttpContext;
         var hasParam = ctx?.Request?.Query.TryGetValue("showdrafts", out var val) == true
                        && val.ToString().Equals("true", StringComparison.OrdinalIgnoreCase);

         return hasParam
                || contextModeResolver.CurrentMode == ContextMode.Edit
                || contextModeResolver.CurrentMode == ContextMode.Preview;
     }
    }

    protected override bool IsInEditMode()
    {
     return IsDraftView;
    }
     
    public override void Render(IHtmlHelper htmlHelper, ContentArea contentArea)
    {
        if (contentArea == null || contentArea.IsEmpty)
            return;

        var items = IsDraftView
            ? contentArea.Fragments.OfType<ContentFragment>().Select(f => new ContentAreaItem(f))
            : contentArea.Fragments.GetFilteredFragments(PrincipalInfo.CurrentPrincipal)
                .OfType<ContentFragment>()
                .Select(f => new ContentAreaItem(f));

        RenderContentAreaItems(htmlHelper, items);
    }
}