CODEWITHSUNDEEP
c#xml-serialization
user107779
user107779

Reputation: 41

How to add attributes for C# XML Serialization

I am having an issue with serializing and object, I can get it to create all the correct outputs except for where i have an Element that needs a value and an attribute. Here is the required output:

<Root>
  <Method>Retrieve</Method>
  <Options>
    <Filter>
      <Times>
        <TimeFrom>2009-06-17</TimeFrom>
      </Times>
      <Document type="word">document name</Document>
    </Filter>
  </Options>
</AdCourierAPI>

I can build all of it but can not find a way to set the Document type attribute, here is a segment of the object class

[XmlRoot("Root"), Serializable]    
public class Root    
{    
    [XmlElement("Method")]    
    public string method="RetrieveApplications";    
    [XmlElement("Options")]    
    public _Options Options;    
}    
public class _Options    
{
    [XmlElement("Filter")]    
    public _Filter Filter;    
}
public class _Filter    
{
    [XmlElement("Times")]    
    public _Times Times;    
    [XmlElement("Documents")]    
    public string Documents;    
}

which gives me:

<Document>document name</Document>

rather than: 

<Document type="word">document name</Document>

but I can not find a way to correct this, please advise.

Thanks

Upvotes: 41

Views: 74547

Answers (4)

Krzysztof Juszcze
Krzysztof Juszcze

Reputation: 467

You can use XmlWriter instead XmlSerialization to get this effect. It is more complex but if you have a lot of strings in model it will be cleaner solution.

Create your own CustomeAttribute, for example:

[System.AttributeUsage(AttributeTargets.Property, AllowMultiple = false)]
public class MyCustomAttribute : System.Attribute
{
    public MyCustomAttribute (string type)
    {
        MyType = type;
    }
    public string MyType { get; set; }
}

Then in model add it, like that:

public class MyModel
{
    [MyCustom("word")]
    public string Document { get; set; }
    [MyCustom("time")]
    public string Time { get; set; }
}

The last part is to create xml with this arguments. You can do it likes that:

        var doc = new XmlDocument();
        MyModel myModel = new MyModel();//or get it from somewhere else
        using (Stream s = new MemoryStream())
        {
            var settings = new XmlWriterSettings();
            settings.Async = true;
            settings.Indent = true;
            var writer = XmlTextWriter.Create(s, settings);
            await writer.WriteStartDocumentAsync();
            await writer.WriteStartElementAsync(null,"Root", null);

            myModel.GetType().GetProperties().ToList().ForEach(async p =>
            {
                dynamic value = p.GetValue(myModel);
                writer.WriteStartElement(p.Name);
                var myCustomAttribute = p.GetCustomAttributes(typeof(MyCustomAttribute), false).FirstOrDefault() as MyCustomAttribute;
                if(myCustomAttribute != null)
                {
                    await writer.WriteAttributeStringAsync(null, "MyType", null, myCustomAttribute.MyType );
                }

                writer.WriteValue(value);
                await writer.WriteEndElementAsync();
            });

            await writer.WriteEndElementAsync();
            await writer.FlushAsync();
            s.Position = 0;
            doc.Load(s);                
            writer.Close();
        }
        string myXml = doc.OuterXml

In myXml should be something like that: (values are examples)

<?xml version="1.0" encoding="utf-8"?>
<Root>
    <Document MyType="word">something</Document>
    <Time MyType="time">11:31:29</Time>
</Root>

You can do it in other way, of course. Here you have some docs which helped me: https://learn.microsoft.com/en-us/dotnet/api/system.xml.xmlwriter?view=netframework-4.8#writing_elements

Upvotes: 0

bruno conde
bruno conde

Reputation: 48255

Where do you have the type stored?

Normally you could have something like:

class Document {
    [XmlAttribute("type")]
    public string Type { get; set; }
    [XmlText]
    public string Name { get; set; }
}


public class _Filter    
{
    [XmlElement("Times")]    
    public _Times Times;    
    [XmlElement("Document")]    
    public Document Document;    
}

Upvotes: 63

Marc Gravell
Marc Gravell

Reputation: 1064204

It sounds like you need an extra class:

public class Document
{
    [XmlAttribute("type")]
    public string Type { get; set; }
    [XmlText]
    public string Name { get; set; }
}

Where an instance (in the example) would have Type = "word" and Name = "document name"; documents would be a List<Document>.

By the way - public fields are rarely a good idea...

Upvotes: 8

Thomas Levesque
Thomas Levesque

Reputation: 292725

The string class doesn't have a type property, so you can't use it to create the desired output. You should create a Document class instead :

public class Document
{
    [XmlText]
    public string Name;

    [XmlAttribute("type")]
    public string Type;
}

And you should change the Document property to type Document

Upvotes: 11

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