Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web/ModelBinding/DefaultModelBinder.cs

@@ -0,0 +1,41 @@
+namespace System.Web.ModelBinding {
+    using System;
+
+    public class DefaultModelBinder : IModelBinder {
+
+        public DefaultModelBinder() {
+            Providers = ModelBinderProviders.Providers;
+        }
+
+        public ModelBinderProviderCollection Providers {
+            get;
+            private set;
+        }
+
+        public bool BindModel(ModelBindingExecutionContext modelBindingExecutionContext, ModelBindingContext bindingContext) {
+            ModelBindingContext newBindingContext = bindingContext;
+            IModelBinder binder = Providers.GetBinder(modelBindingExecutionContext, bindingContext);
+            if (binder == null && !String.IsNullOrEmpty(bindingContext.ModelName)
+                && bindingContext.ModelMetadata.IsComplexType) {
+
+                // fallback to empty prefix?
+                newBindingContext = new ModelBindingContext(bindingContext) { 
+                    ModelName = String.Empty,
+                    ModelMetadata = bindingContext.ModelMetadata
+                };
+                binder = Providers.GetBinder(modelBindingExecutionContext, newBindingContext);
+            }
+
+            if (binder != null) {
+                bool boundSuccessfully = binder.BindModel(modelBindingExecutionContext, newBindingContext);
+                if (boundSuccessfully) {
+                    // run validation
+                    newBindingContext.ValidationNode.Validate(modelBindingExecutionContext, parentNode:null);
+                    return true;
+                }
+            }
+
+            return false; // something went wrong
+        }
+    }
+}