Add NullableEnumModelBinder and NullableEnumModelBinderProvider

1 files changed, 47 insertions, 0 deletions

diff --git a/Jellyfin.Api/ModelBinders/NullableEnumModelBinder.cs b/Jellyfin.Api/ModelBinders/NullableEnumModelBinder.cs
new file mode 100644
index 000000000..5d296227e
--- /dev/null
+++ b/Jellyfin.Api/ModelBinders/NullableEnumModelBinder.cs
@@ -0,0 +1,47 @@
+using System;
+using System.ComponentModel;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Mvc.ModelBinding;
+using Microsoft.Extensions.Logging;
+
+namespace Jellyfin.Api.ModelBinders
+{
+    /// <summary>
+    /// Nullable enum model binder.
+    /// </summary>
+    public class NullableEnumModelBinder : IModelBinder
+    {
+        private readonly ILogger<NullableEnumModelBinder> _logger;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="NullableEnumModelBinder"/> class.
+        /// </summary>
+        /// <param name="logger">Instance of the <see cref="ILogger{NullableEnumModelBinder}"/> interface.</param>
+        public NullableEnumModelBinder(ILogger<NullableEnumModelBinder> logger)
+        {
+            _logger = logger;
+        }
+
+        /// <inheritdoc />
+        public Task BindModelAsync(ModelBindingContext bindingContext)
+        {
+            var valueProviderResult = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
+            var elementType = bindingContext.ModelType.GetElementType() ?? bindingContext.ModelType.GenericTypeArguments[0];
+            var converter = TypeDescriptor.GetConverter(elementType);
+            if (valueProviderResult.Length != 0)
+            {
+                try
+                {
+                    var convertedValue = converter.ConvertFromString(valueProviderResult.FirstValue);
+                    bindingContext.Result = ModelBindingResult.Success(convertedValue);
+                }
+                catch (FormatException e)
+                {
+                    _logger.LogWarning(e, "Error converting value.");
+                }
+            }
+
+            return Task.CompletedTask;
+        }
+    }
+}
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