Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

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

@@ -0,0 +1,145 @@
+namespace System.Web.ModelBinding {
+    using System;
+    using System.Collections;
+    using System.ComponentModel;
+    using System.Globalization;
+
+    [Serializable]
+    public class ValueProviderResult {
+
+        private static readonly CultureInfo _staticCulture = CultureInfo.InvariantCulture;
+        private CultureInfo _instanceCulture;
+
+        // default constructor so that subclassed types can set the properties themselves
+        protected ValueProviderResult() {
+        }
+
+        public ValueProviderResult(object rawValue, string attemptedValue, CultureInfo culture) {
+            RawValue = rawValue;
+            AttemptedValue = attemptedValue;
+            Culture = culture;
+        }
+
+        public string AttemptedValue {
+            get;
+            protected set;
+        }
+
+        public CultureInfo Culture {
+            get {
+                if (_instanceCulture == null) {
+                    _instanceCulture = _staticCulture;
+                }
+                return _instanceCulture;
+            }
+            protected set {
+                _instanceCulture = value;
+            }
+        }
+
+        public object RawValue {
+            get;
+            protected set;
+        }
+
+        private static object ConvertSimpleType(CultureInfo culture, object value, Type destinationType) {
+            if (value == null || destinationType.IsInstanceOfType(value)) {
+                return value;
+            }
+
+            // if this is a user-input value but the user didn't type anything, return no value
+            string valueAsString = value as string;
+            if (valueAsString != null && valueAsString.Trim().Length == 0) {
+                return null;
+            }
+
+            TypeConverter converter = TypeDescriptor.GetConverter(destinationType);
+            bool canConvertFrom = converter.CanConvertFrom(value.GetType());
+            if (!canConvertFrom) {
+                converter = TypeDescriptor.GetConverter(value.GetType());
+            }
+            if (!(canConvertFrom || converter.CanConvertTo(destinationType))) {
+                // EnumConverter cannot convert integer, so we verify manually
+                if (destinationType.IsEnum && value is int) {
+                    return Enum.ToObject(destinationType, (int)value);
+                }
+
+                // In case of a Nullable object, we try again with its underlying type.
+                Type underlyingType = Nullable.GetUnderlyingType(destinationType);
+                if (underlyingType != null) {
+                    return ConvertSimpleType(culture, value, underlyingType);
+                }
+
+                string message = String.Format(CultureInfo.CurrentCulture, SR.GetString(SR.ValueProviderResult_NoConverterExists),
+                    value.GetType().FullName, destinationType.FullName);
+                throw new InvalidOperationException(message);
+            }
+
+            try {
+                object convertedValue = (canConvertFrom) ?
+                     converter.ConvertFrom(null /* context */, culture, value) :
+                     converter.ConvertTo(null /* context */, culture, value, destinationType);
+                return convertedValue;
+            }
+            catch (Exception ex) {
+                string message = String.Format(CultureInfo.CurrentCulture, SR.GetString(SR.ValueProviderResult_ConversionThrew),
+                    value.GetType().FullName, destinationType.FullName);
+                throw new InvalidOperationException(message, ex);
+            }
+        }
+
+        public object ConvertTo(Type type) {
+            return ConvertTo(type, null /* culture */);
+        }
+
+        public virtual object ConvertTo(Type type, CultureInfo culture) {
+            if (type == null) {
+                throw new ArgumentNullException("type");
+            }
+
+            CultureInfo cultureToUse = culture ?? Culture;
+            return UnwrapPossibleArrayType(cultureToUse, RawValue, type);
+        }
+
+        private static object UnwrapPossibleArrayType(CultureInfo culture, object value, Type destinationType) {
+            if (value == null || destinationType.IsInstanceOfType(value)) {
+                return value;
+            }
+
+            // array conversion results in four cases, as below
+            Array valueAsArray = value as Array;
+            if (destinationType.IsArray) {
+                Type destinationElementType = destinationType.GetElementType();
+                if (valueAsArray != null) {
+                    // case 1: both destination + source type are arrays, so convert each element
+                    IList converted = Array.CreateInstance(destinationElementType, valueAsArray.Length);
+                    for (int i = 0; i < valueAsArray.Length; i++) {
+                        converted[i] = ConvertSimpleType(culture, valueAsArray.GetValue(i), destinationElementType);
+                    }
+                    return converted;
+                }
+                else {
+                    // case 2: destination type is array but source is single element, so wrap element in array + convert
+                    object element = ConvertSimpleType(culture, value, destinationElementType);
+                    IList converted = Array.CreateInstance(destinationElementType, 1);
+                    converted[0] = element;
+                    return converted;
+                }
+            }
+            else if (valueAsArray != null) {
+                // case 3: destination type is single element but source is array, so extract first element + convert
+                if (valueAsArray.Length > 0) {
+                    value = valueAsArray.GetValue(0);
+                    return ConvertSimpleType(culture, value, destinationType);
+                }
+                else {
+                    // case 3(a): source is empty array, so can't perform conversion
+                    return null;
+                }
+            }
+            // case 4: both destination + source type are single elements, so convert
+            return ConvertSimpleType(culture, value, destinationType);
+        }
+
+    }
+}