fix(sidebar,preview,scaffold,options): pin footer everywhere, visible razor:preview error, namespacePrefix overload, LayoutVariant hintFix/sidebar footer and dogfood batch

CHANGELOG.md

@@ -4,6 +4,31 @@ All notable changes to ShellDocs land here. Format follows [Keep a Changelog](ht
 
 ## [Unreleased]
 
+## [0.1.4-alpha] — 2026-08-22
+
+Second dogfood batch. `0.1.3-alpha` pinned the sidebar footer to a fixed slot but only under the desktop Sidebar variant — footer still floated mid-sidebar on TopNav / mobile drawer / short-tree cases. 
+
+### Fixed
+
+- **Sidebar footer now pins to the bottom in every layout context.** The `0.1.3-alpha` fix only worked in the desktop Sidebar variant — the `flex: 1; min-height: 0` sizing that lets the nav fill its slot was scoped to `.docs-shell-sidebar .docs-sidebar-slot > nav` inside a `@media (min-width: 1024px)` block. On the TopNav variant, the mobile drawer, or any Sidebar site whose tree is shorter than the slot, the nav still collapsed to intrinsic content size and the footer (GitHub link + theme toggle) sat wherever the tree ended, mid-sidebar. Moved `flex: 1; min-height: 0` onto `.docs-sidebar` itself and made `.docs-sidebar-slot` `display: flex; flex-direction: column` in every context. Footer pins hard to the bottom regardless of variant / viewport / item count.
+- **`razor:preview` fences with an unknown outer tag now render a visible error in the frame instead of falling back to a plain code block silently.** Previously `SlotExtractor.TryBuildPreviewSlot` returned `null` when the fence's first tag didn't resolve to a registered component; the fence rendered as regular fenced code with only a build-log warning. Authors chasing "why isn't my icon rendering" would hunt for a nonexistent component bug. Now the same case emits a `PreviewSlot` with `ComponentType = null` and an `Error` message; `PreviewFrame` renders a red-tinted error panel in the render region naming the unknown tag and pointing at `o.RegisterComponent<T>()` / `o.RegisterComponentsFromAssembly<TMarker>()`. Build-log warning still emitted. `PreviewSlot.ComponentType` is now nullable — technically a source-breaking change for callers pattern-matching on it, though external consumers of that type are ~none in the alpha window. [SHELLDOCS_FIXES.md #4]
+
+### Added
+
+- **`RegisterComponentsFromAssembly<TMarker>(string namespacePrefix)` overload.** Registering only components under a specific namespace from a big assembly no longer needs a `Func<Type, bool>` — the common "register everything under my Components namespace" case reads as:
+  ```csharp
+  o.RegisterComponentsFromAssembly<Marker>("ShellIcons.Icons");
+  ```
+  instead of the lambda form. The `Func` overload stays for anything more complex.
+- **`shelldocs init` scaffolded `Program.cs` now surfaces the `LayoutVariant` knob.** Commented-out `// o.LayoutVariant = DocsLayoutVariant.Sidebar;` line right in the `AddShellDocs(...)` block, plus the `RegisterComponentsFromAssembly` hint. First-time consumers no longer have to grep `ShellDocs.Components/Layouts/DocsLayout.razor` to discover the sidebar-variant option exists. [SHELLDOCS_FIXES.md #3]
+
+### Not fixed this batch
+
+Three items from SHELLDOCS_FIXES.md deferred; they need spec-level work rather than a patch:
+
+- **#1 / #2 — `shelldocs build` produces no `index.html`, and `init`/`build` render-mode mismatch.** The scaffolded project is Server-interactive but `build` prints "publish kind: static (Blazor WASM)" and copies the resulting `wwwroot/` — which for a Server-interactive project has no `index.html`, no `_framework/dotnet.js`, no runtime blob. Output is unusable as a static site (blocks GH Pages / Cloudflare / Netlify deploys). Two viable paths (server-side prerender walk of the nav graph, or scaffold WASM Standalone by default) — either is a substantial change to `BuildCommand` and/or `InitCommand`. Design work needs to happen before this lands. Consumers workaround: `dotnet run` locally, skip `shelldocs build`.
+- **#5 — Markdig mangles inline HTML wrappers between component slots in `razor:preview`.** Plain `<span style="color:…">` around a registered component tag inside a preview loses its parent-child relationship after Markdig's inline pass, because SlotExtractor lifts component tags before Markdig sees them. Documented workaround: use registered wrapper components with their own attribute props instead of raw inline HTML. Framework fix would need SlotExtractor to lift-and-preserve trivial wrappers (`<span>`, `<a>`, `<button>`) around component tags.
+
 ## [0.1.3-alpha] — 2026-08-12
 
 Dogfood-driven fixes. Surfaced while writing the per-primitive / per-command / authoring pages on shelldocs.dev (30+ new sidebar entries pushed the tree past viewport height for the first time). One user-visible bug, one visual polish, both landed against the sidebar chrome.

Directory.Build.props

@@ -18,7 +18,7 @@
 
   <!-- Package metadata (applies to any project with IsPackable=true) -->
   <PropertyGroup>
-    <Version>0.1.3-alpha</Version>
+    <Version>0.1.4-alpha</Version>
     <Authors>ShellUI</Authors>
     <Company>ShellUI</Company>
     <Copyright>Copyright © 2026 ShellUI</Copyright>

src/ShellDocs.Components/Chrome/DocsSidebar.razor.css

@@ -1,11 +1,7 @@
 .docs-sidebar {
     display: flex;
     flex-direction: column;
-    /* No `height: 100%` — the parent .docs-sidebar-slot in the sidebar-variant
-       layout already sizes us via `flex: 1; min-height: 0`. Adding height: 100%
-       fights that: it makes this nav match the WHOLE slot height (header
-       included), which pushes the footer (theme + gh links) past the visible
-       area whenever the tree gets tall enough to scroll. */
+    flex: 1;
     min-height: 0;
     font-size: 0.8125rem;
     padding: 0.85rem 0.75rem 0 1rem;

src/ShellDocs.Components/Content/PreviewFrame.razor

@@ -4,8 +4,22 @@
 
 <div class="preview-frame @(_expanded ? "expanded" : "collapsed")">
     <div class="preview-render">
-        <DynamicComponent Type="Preview!.ComponentType"
-                          Parameters="BuildParameters(Preview!.Parameters, Preview!.ChildContentRaw)" />
+        @if (Preview!.ComponentType is not null)
+        {
+            <DynamicComponent Type="Preview!.ComponentType"
+                              Parameters="BuildParameters(Preview!.Parameters, Preview!.ChildContentRaw)" />
+        }
+        else
+        {
+
+            <div class="preview-error" role="alert">
+                <svg class="preview-error-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M10.29 3.86 1.82 18a2 2 0 0 0 1.71 3h16.94a2 2 0 0 0 1.71-3L13.71 3.86a2 2 0 0 0-3.42 0z"/><line x1="12" y1="9" x2="12" y2="13"/><line x1="12" y1="17" x2="12.01" y2="17"/></svg>
+                <div class="preview-error-body">
+                    <div class="preview-error-title">razor:preview error</div>
+                    <div class="preview-error-message">@(Preview!.Error ?? "Unknown error.")</div>
+                </div>
+            </div>
+        }
     </div>
     <div class="preview-code-wrap">
         <pre class="preview-code language-razor" @ref="_codeEl"><code class="language-razor">@Preview!.Code</code></pre>
@@ -72,6 +86,9 @@
 
     [Inject] private IJSRuntime JS { get; set; } = default!;
 
+    /* Only called from the render-region branch guarded by
+       `Preview!.ComponentType is not null`, so the ! here is a safe assertion
+       — never dereferenced when the tag was unknown. */
     private IDictionary<string, object> BuildParameters(IReadOnlyDictionary<string, string> attrs, string? childContentRaw) =>
-        SlotRenderer.BuildParameters(Renderer, Preview!.ComponentType, attrs, childContentRaw);
+        SlotRenderer.BuildParameters(Renderer, Preview!.ComponentType!, attrs, childContentRaw);
 }

src/ShellDocs.Components/Content/PreviewFrame.razor.css

@@ -21,6 +21,50 @@
             transparent 1px, transparent 8px);
 }
 
+.preview-error {
+    display: flex;
+    align-items: flex-start;
+    gap: 0.85rem;
+    max-width: 44rem;
+    padding: 1rem 1.15rem;
+    background: color-mix(in oklch, var(--error, oklch(0.637 0.237 25.331)) 12%, var(--card));
+    border: 1px solid color-mix(in oklch, var(--error, oklch(0.637 0.237 25.331)) 35%, var(--border));
+    border-radius: calc(var(--radius) - 2px);
+    color: var(--foreground);
+    text-align: left;
+}
+.preview-error-icon {
+    width: 1.15rem;
+    height: 1.15rem;
+    flex-shrink: 0;
+    color: var(--error, oklch(0.637 0.237 25.331));
+    margin-top: 0.1rem;
+}
+.preview-error-body {
+    display: flex;
+    flex-direction: column;
+    gap: 0.25rem;
+    min-width: 0;
+}
+.preview-error-title {
+    font-size: 0.8125rem;
+    font-weight: 600;
+    letter-spacing: -0.005em;
+}
+.preview-error-message {
+    font-size: 0.8125rem;
+    color: var(--muted-foreground);
+    line-height: 1.5;
+    word-break: break-word;
+}
+.preview-error-message code {
+    font-family: var(--font-mono);
+    font-size: 0.78rem;
+    background: color-mix(in oklch, var(--foreground) 8%, transparent);
+    padding: 0.05rem 0.3rem;
+    border-radius: 3px;
+}
+
 .preview-code-wrap {
     position: relative;
     border-top: 1px solid var(--border);

src/ShellDocs.Components/Layouts/DocsLayout.razor.css

@@ -43,6 +43,8 @@
     transform: translateX(-100%);
     transition: transform 260ms cubic-bezier(0.16, 1, 0.3, 1);
     z-index: 45;
+    display: flex;
+    flex-direction: column;
 }
 .docs-sidebar-slot.open {
     transform: translateX(0);
@@ -133,10 +135,10 @@
         max-width: 1500px;
         grid-template-columns: var(--sidebar-width) 1fr;
     }
-    /* Sidebar = the floating card */
+    /* Sidebar = the floating card. `display: flex; flex-direction: column`
+       already comes from the base .docs-sidebar-slot rule — we only override
+       the card chrome + positioning here. */
     .docs-shell-sidebar .docs-sidebar-slot {
-        display: flex;
-        flex-direction: column;
         position: sticky;
         top: 0.85rem;
         height: calc(100vh - 1.85rem);
@@ -147,11 +149,8 @@
         margin-right: 0;
         overflow: hidden;
     }
-    /* DocsSidebar's own <nav> must flex-fill so its footer (theme toggle) sticks to the bottom */
-    .docs-shell-sidebar .docs-sidebar-slot > nav {
-        flex: 1;
-        min-height: 0;
-    }
+    /* nav `flex: 1; min-height: 0` moved to the base .docs-sidebar rule so it
+       applies in every layout context, not just desktop Sidebar variant. */
     /* Content = flush to page bg, no border, no shadow */
     .docs-shell-sidebar .docs-main {
         padding: 1.5rem 0 4rem;

src/ShellDocs.Components/ShellDocsOptions.cs

@@ -72,6 +72,24 @@ tag name are silently ignored downstream in TypeRegistry. */
     public ShellDocsOptions RegisterComponentsFromAssembly<TMarker>(Func<Type, bool>? filter = null)
         => RegisterComponentsFromAssembly(typeof(TMarker).Assembly, filter);
 
+
+    public ShellDocsOptions RegisterComponentsFromAssembly<TMarker>(string namespacePrefix)
+    {
+        if (string.IsNullOrEmpty(namespacePrefix))
+            throw new ArgumentException("namespacePrefix must be non-empty.", nameof(namespacePrefix));
+        return RegisterComponentsFromAssembly(typeof(TMarker).Assembly,
+            t => t.Namespace is not null && t.Namespace.StartsWith(namespacePrefix, StringComparison.Ordinal));
+    }
+
+    public ShellDocsOptions RegisterComponentsFromAssembly(Assembly assembly, string namespacePrefix)
+    {
+        if (assembly is null) throw new ArgumentNullException(nameof(assembly));
+        if (string.IsNullOrEmpty(namespacePrefix))
+            throw new ArgumentException("namespacePrefix must be non-empty.", nameof(namespacePrefix));
+        return RegisterComponentsFromAssembly(assembly,
+            t => t.Namespace is not null && t.Namespace.StartsWith(namespacePrefix, StringComparison.Ordinal));
+    }
+
     public ShellDocsOptions RegisterComponentsFromAssembly(Assembly assembly, Func<Type, bool>? filter = null)
     {
         if (assembly is null) throw new ArgumentNullException(nameof(assembly));

src/ShellDocs.Markdown/RenderedDocument.cs

@@ -18,8 +18,9 @@ public record ComponentSlot(
 
 public record PreviewSlot(
     string Id,
-    Type ComponentType,
+    Type? ComponentType,
     IReadOnlyDictionary<string, string> Parameters,
     string Code,
     string Language,
-    string? ChildContentRaw = null) : Slot(Id);
+    string? ChildContentRaw = null,
+    string? Error = null) : Slot(Id);

src/ShellDocs.Markdown/SlotExtractor.cs

@@ -146,17 +146,11 @@ private string ReplaceComponentTags(string text, List<Slot> slots, List<string>
 
         var name = open.Groups["name"].Value;
         var type = _registry.Resolve(name);
-        if (type is null)
-        {
-            warnings.Add($"razor:preview references unknown component <{name}>.");
-            return null;
-        }
-
         var attrs = ParseAttributes(open.Groups["attrs"].Value);
 
-        // Extract inner ChildContent for non-self-closing tags. e.g.
-        //   <CardGrid>...<Card /> <Card />...</CardGrid>
-        // The inner text is what ends up injected as a RenderFragment at render time.
+        /* Extract inner ChildContent for non-self-closing tags even in the
+           error case — Copy button in the error state should still hand back
+           the exact source the author authored. */
         string? childContentRaw = null;
         if (!open.Groups["self"].Success)
         {
@@ -167,6 +161,19 @@ private string ReplaceComponentTags(string text, List<Slot> slots, List<string>
             }
         }
 
+        if (type is null)
+        {
+            /* Unknown component. Emit an error PreviewSlot so PreviewFrame can
+               render a visible "Unknown component <X>" panel in the browser.
+               The pre-fix behavior returned null here, which caused the whole
+               fence to render as a plain code block — silent failure that sent
+               authors hunting for a nonexistent component bug (dogfood log,
+               SHELLDOCS_FIXES.md #4). Warning still emitted for build logs. */
+            var msg = $"Unknown component <{name}>. Register it via `o.RegisterComponent<{name}>()` or `o.RegisterComponentsFromAssembly<TMarker>()`.";
+            warnings.Add($"razor:preview references unknown component <{name}>.");
+            return new PreviewSlot(NewSlotId(), null, attrs, code, "razor", childContentRaw, Error: msg);
+        }
+
         return new PreviewSlot(NewSlotId(), type, attrs, code, "razor", childContentRaw);
     }
 

src/ShellDocs.Templates/ScaffoldTemplates.cs

@@ -180,8 +180,17 @@ public static string ProgramAddShellDocs(string siteName, string githubRepo) =>
             o.ContentRoot = System.IO.Path.Combine(builder.Environment.ContentRootPath, "content");
             o.SiteName = "{{siteName}}";
             o.GitHubRepo = "{{githubRepo}}";
+
+            // Layout: TopNav (default) = classic header + sidebar.
+            // Sidebar = floating sidebar card, no top header (shadcn / fumadocs look).
+            // o.LayoutVariant = DocsLayoutVariant.Sidebar;
+
             o.AddNavLink("Docs", "/docs/introduction");
-            // o.RegisterComponent<MyComponent>();  // for razor:preview blocks
+
+            // Register your own components so authors can drop them into
+            // markdown as `<MyComponent />` or inside a razor:preview fence:
+            //   o.RegisterComponent<MyComponent>();
+            //   o.RegisterComponentsFromAssembly<MyMarker>();
         });
         """;
 

tests/ShellDocs.Tests/MarkdownRendererTests.cs

@@ -114,13 +114,17 @@ Some paragraph.
     }
 
     [Fact]
-    public void Render_UnregisteredTagInPreview_SkipsWithWarning()
+    public void Render_UnregisteredTagInPreview_EmitsErrorSlotAndWarning()
     {
+
         var md = "```razor:preview\n<Missing />\n```";
         var renderer = new MarkdownRenderer();
         var doc = renderer.Render(md);
 
-        Assert.Empty(doc.Slots);
+        var slot = Assert.IsType<PreviewSlot>(Assert.Single(doc.Slots));
+        Assert.Null(slot.ComponentType);
+        Assert.NotNull(slot.Error);
+        Assert.Contains("Missing", slot.Error);
         Assert.NotEmpty(renderer.LastWarnings);
     }