Get an XML datatype from a .NET type?

Question

I'm wondering if there is a library - in .NET or otherwise - that will convert .NET types (eg. Integer, String, etc.) into XML datatypes (eg. int, string). Note that I'm looking to convert types, not the content of variables. For example:

var xmlType = Convert.ToXmlType(typeof(bool));
Assert.That(xmlType.ToString(), Is.EqualTo("boolean"));

I don't mind making a lookup table since I'm not dealing with too many types, but I thought it would be nice to reuse such a thing if it's already out there.

Answer 1

You can use the following code to create the mappings, however it is not a one-to-one mapping. Reducing this to one-to-one will have to be an implementation detail on your end:

var mapping = (from XmlTypeCode cc in Enum.GetValues(typeof(XmlTypeCode))
              let xt = XmlSchemaType.GetBuiltInSimpleType(cc)
              where xt != null
              group cc by xt.Datatype.ValueType into gg
              select new { Type = gg.Key, XmlTypeCodes = gg.ToArray() })
              .ToDictionary(m => m.Type, m => m.XmlTypeCodes);

Sample output:

System.Boolean => Boolean
System.Byte => UnsignedByte
System.Byte[] => HexBinary,Base64Binary
System.DateTime => DateTime,Time,Date,GYearMonth,GYear,GMonthDay,GDay,GMonth
System.Decimal => Decimal,Integer,NonPositiveInteger,NegativeInteger,NonNegative
Integer,PositiveInteger
...

---

A decent approach to solving the one-to-one problem would be to take the first entry in the code table which works for every type but String. This also may not work for newer BCL types, but likely should going forward. It would be a breaking change for MS to rearrange the XmlTypeCode enumeration, but that's not to say this is fool proof:

// same as above except the ToDictionary
.ToDictionary(
    m => m.Type,
    m => m.Type != typeof(string) ? m.XmlTypeCodes.First() : XmlTypeCode.String);