1 files changed, 58 insertions, 0 deletions
diff --git a/src/StardewModdingAPI.Web/Framework/CommaDelimitedModelBinder.cs b/src/StardewModdingAPI.Web/Framework/CommaDelimitedModelBinder.cs
new file mode 100644
index 00000000..119b18e6
--- /dev/null
+++ b/src/StardewModdingAPI.Web/Framework/CommaDelimitedModelBinder.cs
@@ -0,0 +1,58 @@
+using System;
+using System.ComponentModel;
+using System.Reflection;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Mvc.ModelBinding;
+
+namespace StardewModdingAPI.Web.Framework
+{
+    /// <summary>Maps comma-delimited values to an <see cref="System.Collections.Generic.IEnumerable{T}"/> parameter.</summary>
+    /// <remarks>Derived from <a href="https://stackoverflow.com/a/43655986/262123" />.</remarks>
+    public class CommaDelimitedModelBinder : IModelBinder
+    {
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Attempts to bind a model.</summary>
+        /// <param name="bindingContext">The model binding context.</param>
+        public Task BindModelAsync(ModelBindingContext bindingContext)
+        {
+            // validate
+            if (bindingContext == null)
+                throw new ArgumentNullException(nameof(bindingContext));
+
+            // extract values
+            string modelName = bindingContext.ModelName;
+            ValueProviderResult valueProviderResult = bindingContext.ValueProvider.GetValue(modelName);
+            string[] values = valueProviderResult
+                .ToString()
+                .Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
+            Type elementType = bindingContext.ModelType.GetTypeInfo().GenericTypeArguments[0];
+            if (values.Length == 0)
+            {
+                bindingContext.Result = ModelBindingResult.Success(Array.CreateInstance(elementType, 0));
+                return Task.CompletedTask;
+            }
+
+            // map values
+            TypeConverter converter = TypeDescriptor.GetConverter(elementType);
+            Array typedArray = Array.CreateInstance(elementType, values.Length);
+            try
+            {
+                for (int i = 0; i < values.Length; ++i)
+                {
+                    string value = values[i];
+                    object convertedValue = converter.ConvertFromString(value);
+                    typedArray.SetValue(convertedValue, i);
+                }
+            }
+            catch (Exception exception)
+            {
+                bindingContext.ModelState.TryAddModelError(modelName, exception, bindingContext.ModelMetadata);
+            }
+
+            bindingContext.Result = ModelBindingResult.Success(typedArray);
+            return Task.CompletedTask;
+        }
+    }
+}