/* ****************************************************************************
*
* Copyright (c) Microsoft Corporation. All rights reserved.
*
* This software is subject to the Microsoft Public License (Ms-PL).
* A copy of the license can be found in the license.htm file included
* in this distribution.
*
* You must not remove this notice, or any other, from this software.
*
* ***************************************************************************/
namespace System.Web.Mvc{
using System;
using System.Collections;
using System.ComponentModel;
using System.Globalization;
using System.Web.Mvc.Resources;
[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))) {
string message = String.Format(CultureInfo.CurrentUICulture, MvcResources.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.CurrentUICulture, MvcResources.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);
}
}
}
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