Fix zone sort retrieval

Author: Denis-RZ

website/MyWebApp/Controllers/AdminBlockTemplateController.cs

@@ -28,6 +28,11 @@ private async Task LoadPagesAsync()
     {
         ViewBag.Pages = await _db.Pages.AsNoTracking().OrderBy(p => p.Slug).ToListAsync();
         ViewBag.Roles = await _db.Roles.AsNoTracking().OrderBy(r => r.Name).ToListAsync();
+        ViewBag.Zones = await _db.PageSections.AsNoTracking()
+            .Select(s => s.Zone)
+            .Distinct()
+            .OrderBy(z => z)
+            .ToListAsync();
     }
 
     public async Task<IActionResult> Index()
@@ -202,11 +207,11 @@ public async Task<IActionResult> AddToPage(int id, List<int> pageIds, string zon
         }
         foreach (var pageId in pageIds)
         {
-            var sort = await _db.PageSections
+            var maxSort = await _db.PageSections
                 .Where(s => s.PageId == pageId && s.Zone == zone)
-                .Select(s => s.SortOrder)
-                .DefaultIfEmpty(-1)
-                .MaxAsync() + 1;
+                .Select(s => (int?)s.SortOrder)
+                .MaxAsync();
+            var sort = (maxSort ?? -1) + 1;
             var section = new PageSection
             {
                 PageId = pageId,
@@ -235,11 +240,11 @@ private async Task AddSectionsAsync(BlockTemplate template, List<int>? pageIds,
         }
         foreach (var pageId in pageIds)
         {
-            var sort = await _db.PageSections
+            var maxSort = await _db.PageSections
                 .Where(s => s.PageId == pageId && s.Zone == zone)
-                .Select(s => s.SortOrder)
-                .DefaultIfEmpty(-1)
-                .MaxAsync() + 1;
+                .Select(s => (int?)s.SortOrder)
+                .MaxAsync();
+            var sort = (maxSort ?? -1) + 1;
             var section = new PageSection
             {
                 PageId = pageId,

website/MyWebApp/Views/AdminBlockTemplate/AddToPage.cshtml

@@ -22,7 +22,12 @@
     </div>
     <div>
         <label>Zone</label>
-        <input type="text" name="zone" />
+        <select id="zone-select" name="zone">
+            @foreach (var z in ViewBag.Zones as List<string>)
+            {
+                <option value="@z">@z</option>
+            }
+        </select>
     </div>
     <div>
         <label>Role</label>

website/MyWebApp/Views/AdminBlockTemplate/_PageAssignment.cshtml

@@ -14,7 +14,12 @@
     </div>
     <div>
         <label>Zone</label>
-        <input type="text" name="zone" />
+        <select id="zone-select" name="zone">
+            @foreach (var z in ViewBag.Zones as List<string>)
+            {
+                <option value="@z">@z</option>
+            }
+        </select>
     </div>
     <div>
         <label>Role</label>