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

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?

Deserialize your xml into classes that implement the interface. That's the easiest way to do it. Try it in a small prototype. — , Dec 11 '15 at 21:40
in your case if i have difficult structure of xml (15 levels at least), i will have to define many classes for deserialization, bind to objects instead of xdoc and have many data sourcez — vitm, Dec 13 '15 at 06:48
Eh, then create an object graph and do the translation yourself. — , Dec 14 '15 at 14:00

score 0 · Answer 1 · answered Dec 14 '15 at 14:02

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>();
        }
}

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

1 Answers1