Switched Mode to Enum as per feedback.

Author: datvm

samples/KristofferStrube.Blazor.FileSystemAccess.WasmExample/Pages/OpenDirectory.razor

@@ -50,7 +50,7 @@ else
         {
             handler = await FileSystemAccessService.ShowDirectoryPickerAsync(new DirectoryPickerOptionsStartInFileSystemHandle()
                 {
-                    Mode = write ? "readwrite" : "read",
+                    Mode = write ? FileSystemPermissionMode.ReadWrite : FileSystemPermissionMode.Read,
                 });
 
             await LoadItemsAsync();
@@ -79,15 +79,15 @@ else
 
                 if (existing is not null)
                 {
-                    await Js.InvokeVoidAsync("alert", "File already exist");
+                    await Js.InvokeVoidAsync("alert", "The file is already exist!");
                     return;
                 }
             }
             catch (Exception)
             {
                 // File does not exist
             }
-            
+
             var fileHandle = await handler!.GetFileHandleAsync(FileName, new()
                 {
                     Create = true,

src/KristofferStrube.Blazor.FileSystemAccess/Options/DirectoryPickerOptions.cs

@@ -44,7 +44,7 @@ internal override ExpandoObject Serializable()
 public abstract class BaseDirectoryPickerOptions
 {
     public string? Id { get; set; }
-    public string? Mode { get; set; }
+    public FileSystemPermissionMode Mode { get; set; } = FileSystemPermissionMode.Read;
 
     internal virtual ExpandoObject Serializable()
     {
@@ -54,10 +54,12 @@ internal virtual ExpandoObject Serializable()
             res.id = Id;
         }
 
-        if (Mode != null)
+        res.mode = Mode switch
         {
-            res.mode = Mode;
-        }
+            FileSystemPermissionMode.Read => "read",
+            FileSystemPermissionMode.ReadWrite => "readwrite",
+            _ => throw new NotSupportedException($"Unknown Mode value: {Mode}"),
+        };
 
         return res;
     }