Read XML with Xdocument

Question

My class:

public class Device
{
     int ID;
     string Name;
     List<Function> Functions;
}

And Class Function:

public class Function
{
     int Number;
     string Name;
}

And i have xml file of this structure:

 <Devices>
   <Device Number="58" Name="Default Device" >
     <Functions>
         <Function Number="1" Name="Default func" />
         <Function Number="2" Name="Default func2" />
         <Function Number="..." Name="...." />
     </Functions>
   </Device>
 </Devices>

Here is the code, where i'm trying to read objects:

  var list = from tmp in document.Element("Devices").Elements("Device")
                       select new Device()
                       {
                           ID = Convert.ToInt32(tmp.Attribute("Number").Value),
                           Name = tmp.Attribute("Name").Value,
                           //??????
                       };
            DevicesList.AddRange(list);

how i can read "Functions"???

Answer 1

Do the same thing again, using Elements and Select to project a set of elements to objects.

var list = document
     .Descendants("Device")
     .Select(x => new Device {
                     ID = (int) x.Attribute("Number"),
                     Name = (string) x.Attribute("Name"),
                     Functions = x.Element("Functions")
                                  .Elements("Function")
                                  .Select(f =>
                                      new Function {
                                      Number = (int) f.Attribute("Number"),
                                      Name = (string) f.Attribute("Name")
                                    }).ToList()
                  });

For clarity, I'd actually suggest writing a static FromXElement method in each of Device and Function. Then each bit of code can just do one thing. So for example, Device.FromXElement might look like this:

public static Device FromXElement(XElement element)
{
    return new Device
    {
        ID = (int) element.Attribute("Number"),
        Name = (string) element.Attribute("Name"),
        Functions = element.Element("Functions").Elements("Function")
                         .Select(Function.FromXElement)
                         .ToList();
    };
}

This also allows you to make the setters private within the classes, so they can be publicly immutable (with a bit of effort around the collections).