public override Object ConvertValueToType(Type expectedType, Object value, Object additionalInformation)
{
if (expectedType == null)
{
return(value);
}
if (value == null)
{
if (expectedType.IsValueType)
{
return(Activator.CreateInstance(expectedType));
}
return(null);
}
if (expectedType.IsAssignableFrom(value.GetType()))
{
return(value);
}
Object sourceValue = value;
while (true)
{
Type sourceClass = sourceValue.GetType();
IDedicatedConverter dedicatedConverter = converters.GetExtension(sourceClass, expectedType);
if (dedicatedConverter == null)
{
break;
}
Object targetValue;
try
{
targetValue = dedicatedConverter.ConvertValueToType(expectedType, sourceClass, sourceValue, additionalInformation);
}
catch (Exception e)
{
throw RuntimeExceptionUtil.Mask(e, "Error occured while converting value: " + sourceValue);
}
if (targetValue == null)
{
if (expectedType.IsValueType)
{
throw new Exception("It is not allowed that an instance of " + typeof(IDedicatedConverter).FullName + " returns null like "
+ dedicatedConverter + " did for conversion from '" + sourceClass.FullName + "' to '" + expectedType + "'");
}
return(null);
}
if (expectedType.IsAssignableFrom(targetValue.GetType()))
{
return(targetValue);
}
if (targetValue.GetType().Equals(sourceValue.GetType()))
{
throw new Exception("It is not allowed that an instance of " + typeof(IDedicatedConverter).FullName
+ " returns a value of the same type (" + targetValue.GetType().FullName + ") after conversion like " + dedicatedConverter
+ " did");
}
sourceValue = targetValue;
}
if (expectedType.IsArray && sourceValue != null && sourceValue.GetType().IsArray)
{
// try to convert item by item of the array
Array sourceArray = (Array)sourceValue;
int size = sourceArray.GetLength(0);
Type expectedComponentType = expectedType.GetElementType();
Array targetValue = Array.CreateInstance(expectedComponentType, size);
for (int a = sourceArray.GetLength(0); a-- > 0;)
{
Object sourceItem = sourceArray.GetValue(a);
Object targetItem = ConvertValueToType(expectedComponentType, sourceItem);
targetValue.SetValue(targetItem, a);
}
return(targetValue);
}
return(DefaultConversionHelper.ConvertValueToType(expectedType, sourceValue, additionalInformation));
}
public void UnregisterDedicatedConverter(IDedicatedConverter dedicatedConverter, Type sourceType, Type targetType)
{
converters.Unregister(dedicatedConverter, sourceType, targetType);
}
