first commit

Nitrox.Launcher/Models/Validators/FileNameAttribute.cs

@@ -0,0 +1,28 @@
+using System.ComponentModel.DataAnnotations;
+using System.IO;
+using System.Linq;
+
+namespace Nitrox.Launcher.Models.Validators;
+
+/// <summary>
+///     Tests that the value is usable as file name (excluding validity as file path or file extension).
+/// </summary>
+public sealed class FileNameAttribute : TypedValidationAttribute<string>
+{
+    internal static readonly char[] InvalidPathCharacters = Path.GetInvalidFileNameChars();
+
+    protected override ValidationResult IsValid(string value, ValidationContext context)
+    {
+        if (value == null)
+        {
+            return ValidationResult.Success;
+        }
+        int indexOfAny = value.IndexOfAny(InvalidPathCharacters);
+        if (indexOfAny > -1)
+        {
+            return new ValidationResult($"{context.DisplayName} must not contain '{value[indexOfAny]}'. All invalid characters: {string.Join(' ', InvalidPathCharacters.Where(c => c > 31))}");
+        }
+
+        return ValidationResult.Success;
+    }
+}