Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/System.Web/ModelBinding/FormAttribute.cs

@@ -0,0 +1,43 @@
+namespace System.Web.ModelBinding {
+    using System;
+
+    [AttributeUsage(AttributeTargets.Parameter, Inherited = false, AllowMultiple = false)]
+    public sealed class FormAttribute : ValueProviderSourceAttribute, IUnvalidatedValueProviderSource {
+
+        private bool _validateInput = true;
+
+        public string FieldName {
+            get;
+            private set;
+        }
+
+        public FormAttribute()
+            : this(null) {
+        }
+
+        public FormAttribute(string fieldName) {
+            FieldName = fieldName;
+        }
+
+        public override IValueProvider GetValueProvider(ModelBindingExecutionContext modelBindingExecutionContext) {
+            if (modelBindingExecutionContext == null) {
+                throw new ArgumentNullException("modelBindingExecutionContext");
+            }
+
+            return new FormValueProvider(modelBindingExecutionContext);
+        }
+
+        public override string GetModelName() {
+            return FieldName;
+        }
+
+        public bool ValidateInput {
+            get {
+                return _validateInput;
+            }
+            set {
+                _validateInput = value;
+            }
+        }
+    }
+}