Develop Reference

xml serialisation best practices

I have been using the traditional way of serializing content with the following code
private void SaveToXml(IdentifiableEntity IE)
{
try
{
XmlSerializer serializer = new XmlSerializer(IE.GetType());
TextWriter textWriter = new StreamWriter(IE.FilePath);
serializer.Serialize(textWriter, IE);
textWriter.Close();
}
catch (Exception e )
{
Console.WriteLine("erreur : "+ e);
}
}
private T LoadFromXml<T>(string path)
{
XmlSerializer deserializer = new XmlSerializer(typeof(T));
TextReader textReader = new StreamReader(path);
T entity = (T)deserializer.Deserialize(textReader);
textReader.Close();
return entity;
}
Though this approach does the trick, i find it a bit annoying that all my properties have to be public, that i need to tag the properties sometimes [XmlAttribute|XmlElement| XmlIgnore] and that it doesn't deal with dictionaries.
My question is : Is there a better way of serializing objects in c#, a way that with less hassle, more modern and easy to use?

First of all, I would suggest to use "using" blocks in your code.(Sample code)
If my understanding is OK, you are looking for a fast way to build your model classes that you will use during your deserialize/serialize operations.
Every Xml file is different and I don't know any generic way to serialize / deserialize them. At one moment you have to know if there will be an attribute, or elements or if any element can be null etc.
Assuming that you already have a sample XML file with a few lines which gives you general view of how it will look like
I would suggest to use xsd (miracle tool)
xsd yourXMLFileName.xml
xsd yourXMLFileName.xsd \classes
This tool will generate you every time model classes for the XML file you want to work it.
Than you serialize and deserialize easily
To deserialize (assuming that you'll get a class named XXXX representing root node in your xml)
XmlSerializer ser = new XmlSerializer(typeof(XXXX));
XXXX yourVariable;
using (XmlReader reader = XmlReader.Create(#"C:\yyyyyy\yyyyyy\YourXmlFile.xml"))
{
yourVariable= (XXXX) ser.Deserialize(reader);
}
To serialize
var serializer = new XmlSerializer(typeof(XXXX));
using(var writer = new StreamWriter(#"C:\yyyyyy\yyyyyy\YourXmlFile.xml"))
{
serializer.Serialize(writer, yourVariable);
}

How to use XmlTextWriter to write a object into XML?

I generated a Class with a XML Schema (.xsd) using the Visual Studio xsd tool. Now I have the class and I want to output that object back into XML as defined by my xsd. I am wondering how to do that.
Thank you!

You need an XmlSerializer to take care of serializing your class:
using System.Text; // needed to specify output file encoding
using System.Xml;
using System.Xml.Serialization; // XmlSerializer lives here
// instance of your generated class
YourClass c = new YourClass();
// wrap XmlTextWriter into a using block because it supports IDisposable
using (XmlTextWriter tw = new XmlTextWriter(#"C:\MyClass.xml", Encoding.UTF8))
{
// create an XmlSerializer for your class type
XmlSerializer xs = new XmlSerializer(typeof(YourClass));
xs.Serialize(tw, c);
}

How to set xmlns when serializing object in c#

I am serializing an object in my ASP.net MVC program to an xml string like this;
StringWriter sw = new StringWriter();
XmlSerializer s = new XmlSerializer(typeof(mytype));
s.Serialize(sw, myData);
Now this give me this as the first 2 lines;
<?xml version="1.0" encoding="utf-16"?>
<GetCustomerName xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
my question is,
How can I change the xmlns and the encoding type, when serializing?
Thanks

What I found that works was to add this line to my class,
[System.Xml.Serialization.XmlRootAttribute(Namespace = "http://myurl.com/api/v1.0", IsNullable = true)]
and add this to my code to add namespace when I call serialize
XmlSerializerNamespaces ns1 = new XmlSerializerNamespaces();
ns1.Add("", "http://myurl.com/api/v1.0");
xs.Serialize(xmlTextWriter, FormData, ns1);
as long as both namespaces match it works well.

The XmlSerializer type has a second parameter in its constructor which is the default xml namespace - the "xmlns:" namespace:
XmlSerializer s = new XmlSerializer(typeof(mytype), "http://yourdefault.com/");
To set the encoding, I'd suggest you use a XmlTextWriter instead of a straight StringWriter and create it something like this:
XmlWriterSettings settings = new XmlWriterSettings();
settings.Encoding = Encoding.UTF8;
XmlTextWriter xtw = XmlWriter.Create(filename, settings);
s.Serialize(xtw, myData);
In the XmlWriterSettings, you can define a plethora of options - including the encoding.

Take a look at the attributes that control XML serialization in .NET.
Specifically, the XmlTypeAttribute may be useful for you. If you're looking to change the default namespace for you XML file, there is a second parameter to the XmlSerializer constructor where you can define that.

How to stop XmlSerializer from adding newlines to blank elements

I am serializing an object like this:
XmlSerializer serializer = new XmlSerializer(obj.GetType());
using (StringWriter writer = new StringWriter())
{
serializer.Serialize(writer, obj);
return writer.ToString();
}
(having created the nodes like this)
XmlElement newchild = doc.CreateElement(nodename);
newchild.InnerText = data;
targetnode.AppendChild(newchild);
if data!="" all is well and serializer returns:
<mynode>TheData</mynode>
If data=="" the serializer returns:
<mynode>
</mynode>
Where did that blank line come from?
I've tried the obvious like only setting newchild.InnerText=data when data is nonblank.

In XML both <mynode><\mynode> and <mynode>\n</mynode> are equivalent, so it should not matter, but you could modify the underlining XMLWriter to Serialize the output the way you want it.

Found a simple route
if (data.Length == 0) newchild.IsEmpty = true;
else newchild.InnerText = data;
hope this helps someone.

Creating an XML Element object from an XML Writer in C#

I'm writing a Windows service in C#. I've got an XmlWriter which is contains the output of an XSLT transformation. I need to get the XML into an XMLElement object to pass to a web service.
What is the best way to do this?

You do not need an intermediate string, you can create an XmlWriter that writes directly into an XmlNode:
XmlDocument doc = new XmlDocument();
using (XmlWriter xw = doc.CreateNavigator().AppendChild()) {
// Write to `xw` here.
// Nodes written to `xw` will not appear in the document
// until `xw` is closed/disposed.
}
and pass xw as the output of the transform.
NB. Some parts of the xsl:output will be ignored (e.g. encoding) because the XmlDocument will use its own settings.

Well, an XmlWriter doesn't contain the output; typically, you have a backing object (maybe a StringBuilder or MemoryStream) that is the dumping place. In this case, StringBuilder is probably the most efficient... perhaps something like:
StringBuilder sb = new StringBuilder();
using (XmlWriter writer = XmlWriter.Create(sb))
{
// TODO write to writer via xslt
}
string xml = sb.ToString();
XmlDocument doc = new XmlDocument();
doc.LoadXml(xml);
XmlElement el = doc.DocumentElement;

If you provide a writer, you provide a repository where an output generator is transferring data, thus the replay of Richard is good, you don't really need a string builder to send data from a reader to an XmlDocument!