XmlUnionConverter.cs

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namespace System.Xml.Schema;
 
internal sealed class XmlUnionConverter : XmlBaseConverter
{
    private readonly XmlValueConverter[] _converters;
 
    private readonly bool _hasAtomicMember;
 
    private readonly bool _hasListMember;
 
    private XmlUnionConverter(XmlSchemaType schemaType)
        : base(schemaType)
    {
        while (schemaType.DerivedBy == XmlSchemaDerivationMethod.Restriction)
        {
            schemaType = schemaType.BaseXmlSchemaType;
        }
        XmlSchemaSimpleType[] baseMemberTypes = ((XmlSchemaSimpleTypeUnion)((XmlSchemaSimpleType)schemaType).Content).BaseMemberTypes;
        _converters = new XmlValueConverter[baseMemberTypes.Length];
        for (int i = 0; i < baseMemberTypes.Length; i++)
        {
            _converters[i] = baseMemberTypes[i].ValueConverter;
            if (baseMemberTypes[i].Datatype.Variety == XmlSchemaDatatypeVariety.List)
            {
                _hasListMember = true;
            }
            else if (baseMemberTypes[i].Datatype.Variety == XmlSchemaDatatypeVariety.Atomic)
            {
                _hasAtomicMember = true;
            }
        }
    }
 
    public static XmlValueConverter Create(XmlSchemaType schemaType)
    {
        return new XmlUnionConverter(schemaType);
    }
 
    public override object ChangeType(object value, Type destinationType, IXmlNamespaceResolver nsResolver)
    {
        if (value == null)
        {
            throw new ArgumentNullException("value");
        }
        if (destinationType == null)
        {
            throw new ArgumentNullException("destinationType");
        }
        Type type = value.GetType();
        if (type == XmlBaseConverter.XmlAtomicValueType && _hasAtomicMember)
        {
            return ((XmlAtomicValue)value).ValueAs(destinationType, nsResolver);
        }
        if (type == XmlBaseConverter.XmlAtomicValueArrayType && _hasListMember)
        {
            return XmlAnyListConverter.ItemList.ChangeType(value, destinationType, nsResolver);
        }
        if (type == XmlBaseConverter.StringType)
        {
            if (destinationType == XmlBaseConverter.StringType)
            {
                return value;
            }
            XsdSimpleValue xsdSimpleValue = (XsdSimpleValue)base.SchemaType.Datatype.ParseValue((string)value, new NameTable(), nsResolver, createAtomicValue: true);
            return xsdSimpleValue.XmlType.ValueConverter.ChangeType((string)value, destinationType, nsResolver);
        }
        throw CreateInvalidClrMappingException(type, destinationType);
    }
}