Log file changes

New: Update log files are available in the UI
Fixed: UI error after clearing log files

src/NzbDrone.Api/Frontend/Mappers/UpdateLogFileMapper.cs

@@ -0,0 +1,32 @@
+using System.IO;
+using NLog;
+using NzbDrone.Common;
+using NzbDrone.Common.Disk;
+using NzbDrone.Common.EnvironmentInfo;
+
+namespace NzbDrone.Api.Frontend.Mappers
+{
+    public class LogFileMapper : StaticResourceMapperBase
+    {
+        private readonly IAppFolderInfo _appFolderInfo;
+
+        public LogFileMapper(IAppFolderInfo appFolderInfo, IDiskProvider diskProvider, Logger logger)
+            : base(diskProvider, logger)
+        {
+            _appFolderInfo = appFolderInfo;
+        }
+
+        protected override string Map(string resourceUrl)
+        {
+            var path = resourceUrl.Replace('/', Path.DirectorySeparatorChar);
+            path = Path.GetFileName(path);
+
+            return Path.Combine(_appFolderInfo.GetLogFolder(), path);
+        }
+
+        public override bool CanHandle(string resourceUrl)
+        {
+            return resourceUrl.StartsWith("/logfile/") && resourceUrl.EndsWith(".txt");
+        }
+    }
+}