Relization of XElement, XAttribute + IDataErrorInfo for binding in wpf app - mvvm

Question

I use mvvm pattern in wpf app. As datasource i've XDocument. In UI i bind controls to XElements and XAttribute's values from this XDocument.
f.ex.
<TextBox Text={Binding XElement[TitleNode].XElement[Title].Value} />
It allows me to have data in only place - in XDoc and allows to avoid data conversion from custom models to xml.
Now I need to extend functionality of model with IDataErrorInfo to realize error notification. So i need to add interface to XElement and XAttribute .net classes.
i've 2 decisions:
1) pattern adapter for xelement and xattribute, that will have adaptee, realiztion of interface IDataErrorInfo and Value setter\getter for xelement\xattribute's value. Weakness - i need create adapter-objects for all UI input control and bind to it.
2) Create child class and inherite from XElement\XAttribute with interface realization. Weekness - i need to convert all xelements and xattributes to my child class.
What way is better?

Answer 1

The best way I guess is to inherite from XElement/XAttribute and add interface you need.
I created 2 child class XElementCustom and XAttributeCustom. And in constructor the whole tree is recreated recursively
That's my realization:
/// <summary>
/// Наследник XML с реализацией INotifyPropertyChanged
/// </summary>
public class XElementCustom : XElement, INotifyPropertyChanged, IDataErrorInfo, IDataErrorInfoValidating
{
public XElementCustom(XElement sourceElement)
:base(sourceElement.Name.LocalName)
{
if (sourceElement.Elements().Any())
{
foreach (var element in sourceElement.Elements())
{
this.Add(new XElementCustom(element));
}
}
else
{
this.Value = sourceElement.Value;
}
foreach (var attribute in sourceElement.Attributes())
{
this.Add(new XAttributeCustom(attribute));
}
_changedProperties = new List<string>();
}
}