Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

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

@@ -0,0 +1,50 @@
+namespace System.Web.ModelBinding {
+    using System;
+    using System.ComponentModel.DataAnnotations;
+    using System.Globalization;
+    using System.Reflection;
+
+    public class DataAnnotationsModelMetadata : ModelMetadata {
+        private DisplayColumnAttribute _displayColumnAttribute;
+
+        public DataAnnotationsModelMetadata(DataAnnotationsModelMetadataProvider provider, Type containerType,
+                                            Func<object> modelAccessor, Type modelType, string propertyName,
+                                            DisplayColumnAttribute displayColumnAttribute)
+            : base(provider, containerType, modelAccessor, modelType, propertyName) {
+            _displayColumnAttribute = displayColumnAttribute;
+        }
+
+        protected override string GetSimpleDisplayText() {
+            if (Model != null) {
+                if (_displayColumnAttribute != null && !String.IsNullOrEmpty(_displayColumnAttribute.DisplayColumn)) {
+                    PropertyInfo displayColumnProperty = ModelType.GetProperty(_displayColumnAttribute.DisplayColumn, BindingFlags.Public | BindingFlags.IgnoreCase | BindingFlags.Instance);
+                    ValidateDisplayColumnAttribute(_displayColumnAttribute, displayColumnProperty, ModelType);
+
+                    object simpleDisplayTextValue = displayColumnProperty.GetValue(Model, new object[0]);
+                    if (simpleDisplayTextValue != null) {
+                        return simpleDisplayTextValue.ToString();
+                    }
+                }
+            }
+
+            return base.GetSimpleDisplayText();
+        }
+
+        private static void ValidateDisplayColumnAttribute(DisplayColumnAttribute displayColumnAttribute, PropertyInfo displayColumnProperty, Type modelType) {
+            if (displayColumnProperty == null) {
+                throw new InvalidOperationException(
+                    String.Format(
+                        CultureInfo.CurrentCulture,
+                        SR.GetString(SR.DataAnnotationsModelMetadataProvider_UnknownProperty),
+                        modelType.FullName, displayColumnAttribute.DisplayColumn));
+            }
+            if (displayColumnProperty.GetGetMethod() == null) {
+                throw new InvalidOperationException(
+                    String.Format(
+                        CultureInfo.CurrentCulture,
+                        SR.GetString(SR.DataAnnotationsModelMetadataProvider_UnreadableProperty),
+                        modelType.FullName, displayColumnAttribute.DisplayColumn));
+            }
+        }
+    }
+}