appendix: 23 Code-Ausschnitte aus dem Houston-Repository

Pin nixpkgs to the revision used by itc.componentware: the channel version
ships a latexminted that crashes on Python 3.14, which made every listing
fail and sent latexmk into an endless error prompt. Also force
nonstopmode/halt-on-error so a broken listing can never loop again.

figures/code/share-page.cs

@@ -0,0 +1,61 @@
+using Houston.Model.Documents;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Http.Extensions;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.RazorPages;
+
+namespace Houston.Pages.Document;
+
+/// <summary>
+/// Anonymous landing page for shared document links. It exposes only metadata derived from the
+/// document id and never fetches or renders file contents.
+/// </summary>
+public class Share : PageModel
+{
+    [BindProperty(SupportsGet = true)]
+    public string Id { get; set; } = String.Empty;
+
+    public string Title { get; private set; } = "Dokument";
+
+    public string ImageUrl { get; private set; } = String.Empty;
+
+    public string ExplorerUrl { get; private set; } = String.Empty;
+
+    public IActionResult OnGet()
+    {
+        var docId = new DocumentId(Id);
+
+        if (!docId.TryDecode(out var relativePath))
+            return NotFound();
+
+        var type = relativePath.Value.Type;
+        var name = relativePath.Value.Name;
+        var iconPath = type.PreviewPath;
+
+        Title = name.DisplayName;
+        ImageUrl = AbsoluteUrl(iconPath);
+        ExplorerUrl = AbsoluteUrl("/documents", BuildExplorerQuery(type, name), $"#{Documents.DocumentViewId(docId)}");
+
+        return Page();
+    }
+
+    private static QueryString BuildExplorerQuery(DocumentType? type, DocumentName name)
+    {
+        return new QueryBuilder {
+            { "q", name.DisplayName },
+            { "types", type.Name }
+        }.ToQueryString();
+    }
+
+    private string AbsoluteUrl(string path, QueryString query = default, string? fragment = null)
+    {
+        return UriHelper.BuildAbsolute(
+            Request.Scheme,
+            Request.Host,
+            Request.PathBase,
+            path,
+            query,
+            fragment: fragment is null ? default : new FragmentString(fragment)
+        );
+    }
+}