public void WriteXml(XmlWriter writer, object value, XmlSerializationContext context)
{
if (context.Member.MappingType != XmlMappingType.Element)
{
throw new XmlSerializationException($"XML mapping of \"{context.ValueType}\" must be Element.");
}
var collectionItem = GetCollectionItem(context);
if (collectionItem == null)
{
throw new XmlSerializationException(
$"XML contract of \"{context.ValueType}\" must contains collection item");
}
Type lastItemType = null;
XmlTypeContext typeContext = null;
foreach (var item in (IEnumerable)value)
{
if (item == null)
{
context.WriteNull(writer, collectionItem.ValueType, collectionItem);
}
else
{
var member = (XmlMember)collectionItem;
var shouldWriteTypeName = context.TryResolveValueType(item, ref member, out Type itemType);
if (itemType != lastItemType)
{
typeContext = context.Settings.GetTypeContext(itemType);
lastItemType = itemType;
}
writer.WriteStartElement(member.Name);
if (shouldWriteTypeName)
{
context.WriteTypeName(writer, lastItemType);
}
context.WriteXml(writer, item, member, typeContext);
writer.WriteEndElement();
}
}
}
public void WriteXml(XmlWriter writer, object value, XmlSerializationContext context)
{
if (context.Member.MappingType != XmlMappingType.Element)
{
throw new XmlSerializationException(string.Format("XML mapping of \"{0}\" must be Element.", context.ValueType));
}
var collectionItem = GetCollectionItem(context);
if (collectionItem == null)
{
throw new XmlSerializationException(string.Format("XML contract of \"{0}\" must contains collection item", context.ValueType));
}
Type lastItemType = null;
XmlTypeContext typeContext = null;
foreach (var listItem in (IEnumerable)value)
{
object item = listItem;
// ignore optional none and unwrap optional because we've already done that in XmlContractResolver.ResolveItem
if (listItem is IAnyOptional optional)
{
if (!optional.HasValue)
{
if (context.Settings.NoneValueHandling == XmlNoneValueHandling.Ignore)
{
continue;
}
// Output default values for inner types
var innerType = optional.GetInnerType();
var nullableInnerType = innerType.GetUnderlyingNullableType();
if (nullableInnerType != null)
{
context.WriteNull(writer, collectionItem.ValueType, collectionItem);
continue;
}
else if (innerType.IsClass)
{
context.WriteNull(writer, collectionItem.ValueType, collectionItem);
continue;
}
}
item = optional.Value;
}
if (item == null)
{
context.WriteNull(writer, collectionItem.ValueType, collectionItem);
continue;
}
var member = (XmlMember)collectionItem;
var shouldWriteTypeName = context.TryResolveValueType(item, ref member, out Type itemType);
if (itemType != lastItemType)
{
typeContext = context.Settings.GetTypeContext(itemType);
lastItemType = itemType;
}
// start writing element
context.WriteElement(writer, item, member, typeContext, itemType, shouldWriteTypeName);
}
}