how to create a class to XmlSerializer

Question

I have the following xml format:

<FavouriteSettings xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"&gt;
  <Customer>
    <ID>12</ID>
    <ID>2</ID>
    <ID>5</ID>
  </Customer>

  <Supplier>
    <ID>158</ID>
    <ID>23</ID>
    <ID>598</ID>
  </Supplier>
</FavouriteSettings>

============================================================= I will have a class like below

class FavouriteList
{
   public string Name; // this name will be "Customer" and "Supplier"
   public List<int> aList; // to store those "ID" value
}

Class FavouriteSettings
{
   public List<FavouriteList> bigList;
}

QUESTION: what do i have to do or change to make this class above to use XMLSerializer to generate the XML file like that format and DeSerializer back to the list and class as FavouriteList ?

Thanks

Answer 1

XMLSerializer (the regular one) like to do its own thing, and the result is often rather ugly. You can semi-control the serialization by implementing IXmlSerializable, however if you have anything like "List" in there, .NET will butcher it.

I think you could get exactly that result using the DataContractXmlSerializer instead. Tag the class with [DataContract] and put a [DataMember] over each element you want serialized.

Answer 2

I believe you can use attributes to control the way the data is serialized. See this MSDN article: "Attributes That Control XML Serialization".

Answer 3

You can use the following classes along with the XmlSerializer to serialize/deserialize to/from your desired XML:

  public class FavouriteSettings
  {
    public ID[] Customer
    {
      get;
      set;
    }

    public ID[] Supplier
    {
      get;
      set;
    }
  }

  public class ID
  {
    [XmlText()]
    public int Value
    {
      get;
      set;
    }
  }

Answer 4

XmlSerializer is designed to be a very direct translation of your objects to xml; you can use IXmlSerializable, but it is rarely worth it. You would do better to create objects that mirror the xml structure. Or, simpler - use xsd to do it for you:

xsd example.xml
xsd example.xsd /classes

Or I suspect the following would work (untested):

using System.Collections.Generic;
using System.Xml.Serialization;
public class FavoriteSettings
{
    [XmlArray("Customer")]
    [XmlArrayItem("ID")]
    public List<int> Customers { get; set; }

    [XmlArray("Supplier")]
    [XmlArrayItem("ID")]
    public List<int> Suppliers { get; set; }
}

In particular; if you want the element names ("Customer" etc) to vary based on data ("Name" etc) - then it isn't going to hapopen unless you use IXmlSerializable, or write it yourself with XDocument (or similar). For simple data like this, maybe XDocument is a viable option? But then you make a lot of extra work, especially during deserialization.

---

Here's an example using your existing class via LINQ-to-XML:

static class Program
{
    static void Main() {
        var favs = new FavouriteSettings
        {
            bigList = new List<FavouriteList>
            {
                new FavouriteList {
                    Name = "Customer",
                    aList = new List<int>{
                        12,2,5
                    }
                }, new FavouriteList {
                    Name = "Supplier",
                    aList = new List<int>{
                        158, 23, 598
                    }
                }
            }
        };
        var el = new XElement("FavoriteSettings",
            from fav in favs.bigList
            select new XElement(fav.Name,
                from item in fav.aList
                select new XElement("ID", item)));

        string xml = el.ToString();
        Console.WriteLine(xml);

        el = XElement.Parse(xml);
        favs = new FavouriteSettings
        {
            bigList = new List<FavouriteList>(
                from outer in el.Elements()
                select new FavouriteList
                {
                    Name = outer.Name.LocalName,
                    aList = new List<int>(
                        from id in outer.Elements("ID")
                        select (int)id
                    )
                })
        };
    }
}

Answer 5

If you must keep all existing names in the class definition as is, and introducing a class hierarchy for Customer and Supplier is out of question, then you'll need a hack like this:

public class FavouriteList
{
   [XmlIgnore]
   public string Name; // this name will be "Customer" and "Supplier"

   [XmlElement("ID")]
   public List<int> aList; // to store those "ID" value
}

public class FavouriteSettings
{
   [XmlIgnore]
   public List<FavouriteList> bigList;

   [XmlElement("Customer")]
   public FavouriteList[] Customers
   {
       get { return bigList.Where(fl => fl.Name == "Customer").ToArray(); }
       set { bigList.AddRange(value); }
   }

   [XmlElement("Supplier")]
   public FavouriteList[] Suppliers
   {
       get { return bigList.Where(fl => fl.Name == "Supplier").ToArray(); }
       set { bigList.AddRange(value); }
   }
}