public override void Load (XmlElement filenode, FilePath baseDirectory)
{
var extAtt = filenode.GetAttributeNode ("extension");
if (extAtt != null)
extension = extAtt.Value ?? "";
propertyInnerText = filenode.InnerText;
if (propertyInnerText == null)
throw new InvalidOperationException ("Property is missing its inner text");
typeAtt = filenode.GetAttributeNode ("type");
if (typeAtt == null)
throw new InvalidOperationException ("Property is missing the type attribute");
if (String.IsNullOrEmpty (typeAtt.Value))
throw new InvalidOperationException ("Property's type attribute is empty");
if (String.IsNullOrEmpty (filenode.InnerText))
throw new InvalidOperationException ("Property is empty");
}