#85: Changed the way next/previous buttons work, and introduced a more consistent ordering when large numbers of photos were uploaded at the same time

app/Http/Controllers/Gallery/AlbumController.php

@@ -71,14 +71,14 @@ class AlbumController extends Controller
         else if ($requestedView != 'slideshow')
         {
             $photos = $album->photos()
-                ->orderBy(DB::raw('COALESCE(taken_at, created_at)'))
+                ->orderBy(DB::raw('COALESCE(taken_at, created_at), name, id'))
                 ->paginate(UserConfig::get('items_per_page'));
         }
         else
         {
             // The slideshow view needs access to all photos, not paged
             $photos = $album->photos()
-                ->orderBy(DB::raw('COALESCE(taken_at, created_at)'))
+                ->orderBy(DB::raw('COALESCE(taken_at, created_at), name, id'))
                 ->get();
         }
 

app/Http/Controllers/Gallery/PhotoController.php

@@ -105,14 +105,40 @@ class PhotoController extends Controller
         // Load the Next/Previous buttons
         $thisPhotoDate = is_null($photo->taken_at) ? $photo->created_at : $photo->taken_at;
 
-        $previousPhoto = $album->photos()
+        // I don't like the idea of using a totally raw SQL query, but it's the only sure-fire way to number the rows
-            ->where(DB::raw('COALESCE(taken_at, created_at)'), '<', $thisPhotoDate)
+        // so we can get the previous/next photos accurately - and we don't have to load all data for the photo objects
-            ->orderBy(DB::raw('COALESCE(taken_at, created_at)'), 'desc')
+        $previousPhoto = null;
-            ->first();
+        $nextPhoto = null;
-        $nextPhoto = $album->photos()
+
-            ->where(DB::raw('COALESCE(taken_at, created_at)'), '>', $thisPhotoDate)
+        $allAlbumPhotos = DB::select(
-            ->orderBy(DB::raw('COALESCE(taken_at, created_at)'))
+            DB::raw(
-            ->first();
+                'SELECT p.id, (@row_number:=@row_number + 1) AS row_number
+                FROM photos p, (SELECT @row_number:=0) AS t
+                WHERE p.album_id = :album_id
+              ORDER BY COALESCE(p.taken_at, p.created_at), p.name, p.id;'
+            ),
+            [
+                'album_id' => $album->id
+            ]
+        );
+
+        for ($i = 0; $i < count($allAlbumPhotos); $i++)
+        {
+            if ($allAlbumPhotos[$i]->id === $photo->id)
+            {
+                if ($i > 0)
+                {
+                    $previousPhoto = Photo::where('id', $allAlbumPhotos[$i - 1]->id)->first();
+                }
+
+                if ($i + 1 < count($allAlbumPhotos))
+                {
+                    $nextPhoto = Photo::where('id', $allAlbumPhotos[$i + 1]->id)->first();
+                }
+
+                break;
+            }
+        }
 
         // Record the visit to the photo
         if (UserConfig::get('enable_visitor_hits'))