Serve 503 when PocketBase is unavailable across all content pages

Elternbeirat.Web/Shared/Cultures.cs

@@ -0,0 +1,21 @@
+using System.Globalization;
+
+namespace Elternbeirat.Web.Shared;
+
+/// <summary>
+///     Shared <see cref="CultureInfo"/> instances used to format visitor-facing
+///     text.
+/// </summary>
+/// <remarks>
+///     Kept in one place so every component renders month and weekday names the
+///     same way, rather than each holding its own <c>de-DE</c> lookup. This is only
+///     for display text; machine-readable output (e.g. an HTML <c>datetime</c>
+///     attribute) uses <see cref="CultureInfo.InvariantCulture"/> instead.
+/// </remarks>
+internal static class Cultures
+{
+    /// <summary>
+    ///     German culture, for the month and weekday names visitors read.
+    /// </summary>
+    public static readonly CultureInfo German = CultureInfo.GetCultureInfo("de-DE");
+}

Elternbeirat.Web/Shared/EventFormat.cs

@@ -1,4 +1,3 @@
-using System.Globalization;
 using Elternbeirat.Contracts;
 
 namespace Elternbeirat.Web.Shared;
@@ -22,11 +21,6 @@ public static class EventFormat
     /// </summary>
     private const string ShortDate = "d. MMMM yyyy";
 
-    /// <summary>
-    ///     The culture used for month and weekday names.
-    /// </summary>
-    private static readonly CultureInfo German = CultureInfo.GetCultureInfo("de-DE");
-
     /// <summary>
     ///     Formats the date range of an event.
     /// </summary>
@@ -54,7 +48,7 @@ public static class EventFormat
             (var start, null, var hasTime)
                 => Stamp(start, LongDate, hasTime),
             (var start, { } end, true) when end.Date == start.Date
-                => $"{start.ToString(LongDate, German)}, {start.ToString("HH:mm", German)}–{end.ToString("HH:mm", German)} Uhr",
+                => $"{start.ToString(LongDate, Cultures.German)}, {start.ToString("HH:mm", Cultures.German)}–{end.ToString("HH:mm", Cultures.German)} Uhr",
             (var start, { } end, false) when end.Date == start.Date
                 => Stamp(start, LongDate, withTime: false),
             (var start, { } end, var hasTime)
@@ -78,6 +72,6 @@ public static class EventFormat
     /// </returns>
     private static string Stamp(DateTime value, string dateFormat, bool withTime)
         => withTime
-            ? value.ToString(dateFormat + ", HH:mm", German) + " Uhr"
-            : value.ToString(dateFormat, German);
+            ? value.ToString(dateFormat + ", HH:mm", Cultures.German) + " Uhr"
+            : value.ToString(dateFormat, Cultures.German);
 }

Elternbeirat.Web/Shared/SourceUnavailable.cs

@@ -0,0 +1,30 @@
+namespace Elternbeirat.Web.Shared;
+
+/// <summary>
+///     Marks the current response as HTTP 503 when the content source is down.
+/// </summary>
+/// <remarks>
+///     Several components handle a <see cref="PocketBase.PocketBaseUnavailableException"/>
+///     the same way: the site works but PocketBase does not, so the response is a
+///     503 and the component renders a "temporarily unavailable" note instead of
+///     empty content that would read as 200 "there is nothing here". This puts the
+///     status-setting in one place so those components do not each repeat it.
+/// </remarks>
+internal static class SourceUnavailable
+{
+    /// <summary>
+    ///     Sets the response status to 503 Service Unavailable, if there is a
+    ///     response to set it on.
+    /// </summary>
+    /// <param name="context">
+    ///     The current HTTP context, or <see langword="null"/> when the component
+    ///     renders outside a request (in which case there is nothing to do).
+    /// </param>
+    public static void SetStatus(HttpContext? context)
+    {
+        if (context is not null)
+        {
+            context.Response.StatusCode = StatusCodes.Status503ServiceUnavailable;
+        }
+    }
+}