Required attributes in XML serialization

Question

For example I have class to serialize

[Serializable]
class Person
{
    [XmlAttribute("name")]
    string Name {get;set;}
}

I need to make Name attribute required. How to do this in .NET?

Answer 1

You could use the XmlIgnoreAttribute along with the <FieldName>Specified pattern to throw an exception if the property is left blank or null. During serialization the NameSpecified property will be checked to determine if the field should be rendered, so if the Name properties left null or empty an exception is thrown.

class Person
{
   [XmlElement("name")]
   string Name { get; set; }
   [XmlIgnore]
   bool NameSpecified
   {
      get { 
              if( String.IsNullOrEmpty(Name)) throw new AgrumentException(...);

              return true;
          }
    }
}

Answer 2

The best way to solve this is by having a separate XSD which you use to validate the XML before you pass it onto the XmlSerializer. The easiest way to work with XSD's and XmlSerializer is to start off with an XSD, generate the code for the XmlSerializer from this XSD and also use it to validate the XML.