We Keep Coding

C# Deserialize XML to correct class type

I am using the XmlSerializer to do some serialization work. I was wondering if it is possible to "generically" deserialize from the XmlDocuement.
Concrete: If I have an XML File I would watch the tag and compare it with my DTO Model. Is this possible (better: Does .NET support this?) ? Maybe using an XSD file or something?
Example (without generic deserialization):
XmlDocument myDocument = new XmlDocument();
myDocument.Load(xml);
MemoryStream stream = new MemoryStream();
myDocument.Save(stream);
// Here I would like to use an interface instead and load the correct type of object.
XmlSerializer serializer = new XmlSerializer(typeof(MyClass));
MyClass myObject;
serializer.Serialize(stream, myObject);

The only way is that you pre parse the xml file so you understand the class to create.
You could also write somewhere (in the file extension? in an attribute of the first element of the doc?) the class type.
When you have the class type you can create the right class via a switch statement (converting a string to a type) or via reflection (better).

Xml Serialization: Is there a way to control xml declaration using attribute(s)

Is there a way to control/tweak xml declaration while serializing an object using attributes in the class.
In other words I am searching for attribute(s) in C# that can be used to decorate my class and will help in tweaking the xml declaration part(attributes in it) while serializing an object of that class. I know that there is a class XmlDeclaration that can be used to achieve it, however I want to achieve the same result using attributes, which I think is cleaner as different processing instruction stays with the POCO classes and which can be varied across different POCO classes.
Kindly let me know if there is any out-of-the-box feature/custom solution for that or this is just another stupid question... :)

As your comment notes you are talking about the XML Declaration
<?xml …>
that can start an XML document.
It appears the direct answer is No: there is no XmlDocumentAttribute or something similarly named in the System.Xml.Serialization namespace.
However, there is no need to have the XML serialisation engine write directly to a file. Rather write to an XmlWriter you have correctly configured to write the XML declaration you want (including none). Then pass that writer to the right Serialize method overload.
See this answer for overriding the default encoding in the XML Declaration.
(While this doesn't answer you question—how to do this with attributes in your POCO types—one can argue that the XML Declaration is all about how the XML in the file is encoded so correctly belongs with the file writing/reading code, not the serialisation code.)

You would need to override the default XmlWriterSettings and set the OmitXmlDeclaration property to true e.g.
XmlWriterSettings writerSettings = new XmlWriterSettings
{
OmitXmlDeclaration = true
};
using (StringWriter strWriter = new StringWriter())
using (XmlWriter xmlWriter = XmlWriter.Create(stringWriter, writerSettings))
{
XmlSerializer serializer = new XmlSerializer(typeof(myObject));
serializer.Serialize(xmlWriter, myObject);
}
Turns out StringWriter defaults to UTF-16, if you need control over the encoding you would need to derive your own StringWriter, there is a good example of how to do that already.

What is the fastest way to convert a class to XML

I would like to know what is the fastest and most lightweight technique to convert a fairly large class to XML. The class will have lists and arrays in it. I need to convert all this data to XML
Here is what my application does:
it will get all the information from the database using linq to enties. Then store the data in a class. Then I want to convert this class to XML. When the data is in XML I will send the XML to the browser along with the xsl stylesheet to be displayed to the user. What is the fastest way to do this.

The XmlSerializer actually creates an assembly (with an XmlSerializationWriter) that is custom made to serialize your class. You can look at the generated code by following these steps.
You only pay the price the first time it encounters a new type.
So I think that you should really go with the XmlSerializer, not only for performance, but for maintainability.
You can use a mixin-like serializer class:
public interface MXmlSerializable { }
public static class XmlSerializable {
public static string ToXml(this MXmlSerializable self) {
if (self == null) throw new ArgumentNullException();
var serializer = new XmlSerializer(self.GetType());
using (var writer = new StringWriter()) {
serializer.Serialize(writer, self);
return writer.GetStringBuilder().ToString();
}
}
}
public class Customer : MXmlSerializable {
public string Name { get; set; }
public bool Preferred { get; set; }
}
// ....
var customer = new Customer {
Name = "Guybrush Threepwood",
Preferred = true };
var xml = customer.ToXml();

The fastest way is to write the code for it yourself. That will remove any overhead, like the need to use reflection to read the properties of the object, as you can access the properties directly.
Add a method to the class that returns it's data as XML, either by returning an XDocument, the XML already formatted as a string, or you can pass an XmlWriter to the method.

By "fastest" do you mean you want the approach which will be fastest to develop? Or do you want the approach which will have the fastest execution speed?
If it's the former, I recommend just using .NET's XmlSerializer class: http://msdn.microsoft.com/en-us/library/system.xml.serialization.xmlserializer.aspx
Serializing a class to XML output is as simple as:
XmlSerializer serializer = new XmlSerializer(myObject.GetType());
serializer.Serialize(Response.OutputStream, myObject);
And there are various attributes you can decorate your class with to control things like whether individual properties are serialized as elements or attributes, etc.
There's a good FAQ at http://www.devolutions.net/articles/serialization.aspx also

You could use XML serialization, for example:
Foo foo = new Foo();
XmlSerializer serializer = new XmlSerializer(typeof(Foo));
TextWriter writer = new StringWriter();
serializer.Serialize(writer, foo);
string xml = writer.ToString();

The fastest method would depend on the class, because it would be hand-written to take advantage of knowledge of the specifics of that class in ways a more general approach couldn't do.
I'd probably use XmlTextWriter rather than straight to TextWriter though. While the latter would allow for some further savings, these would be minimal compared to the better structure of XmlTextWriter, and you've already sacrificed a good bit in terms of structure and ease of maintenance as it is.
You can always slot in your super-optimised implementation of XmlWriter afterwards ;)

It sounds like a rather convoluted set-up, when you could just display the class's information on a webpage using ASP.NET MVC. Why take the extra two steps of converting it to XML, send it to the browser, and use an XSL stylesheet to display it to the user? It doesn't make sense.

I wrote a program that serialized one simple object graph to XML in different ways:
1. Using XmlSerializer
2. Using hardcoded xml serializer
30,000 documents:
XmlSerializer took : 0.9 sec
Hardcoded serializer took: 0.45 sec
I relied on XmlWriter in both cases and that adds some overhead.
Note that you can instruct Visual Studio to generate the XmlSerializer assembly during compile time in order to reduce the serialization for that first instance (otherwise an assembly is generated in runtime).

Creating something similar to System.ServiceModel.Syndication using .NET 3.5

If I am dealing with several standard xml formats what would be the best practice way of encapsulating them in C# 3.5? I'd like to end up with something similar to the System.ServiceModel.Syndication namespace.
A class that encapsulates the ADF 1.0 XML standard would be one example. It has the main XML root node, 6 child elements, 4 of which are required IIRC, several required and optional elements and attributes further down the tree. I'd like the class to create, at a minimum, the XML for all the required pieces all the way up to a full XML representation. (Make sense).
With LINQ 4 XML and extension classes, etc, etc, there has to be some ideas on quickly generating a class structure for use. Yes? No? :)
Am not sure if I gave enough details to get one correct answer but am willing to entertain ideas right now.
TIA

XML serialization seems a good approach. You could even use xsd.exe to generate the classes automatically...
EDIT
Note that the class names generated by the tool are usually not very convenient, so you might want to rename them. You might also want to change arrays of T to List<T>, so that you can easily add items where needed.
Assuming the class for the root element is named ADF, you can load an ADF document as follows :
ADF adf = null;
XmlSerializer xs = new XmlSerializer(typeof(ADF));
using (XmlReader reader = XmlReader.Create(fileName))
{
adf = (ADF)xs.Deserialize(reader);
}
And to save it :
ADF adf = ...; // create or modify your document
...
XmlSerializer xs = new XmlSerializer(typeof(ADF));
using (XmlWriter writer = XmlWriter.Create(fileName))
{
xs.Serialize(writer, adf);
}

Why not just follow the pattern of the SyndicationFeed object in the Syndication namespace? Create a class that takes in a Uri to the xml document or just takes in the document fragment.
Then parse the document based on your standards (this parsing can be done using LinqToXml if you wanted to, though regEx might be faster if you are comfortable with them). Throw exceptions or track errors appropriately when the document doesn't pass the specification rules.
If the document passes the parse step then break the pieces of the document out into public getter properties of your object. Then return the fully hydrated object back to the consumer for use
Seems pretty straight forward to me. Is that what you are after or are you looking for something more than this?

Deserializing XML to Objects in C#

So I have xml that looks like this:
<todo-list>
<id type="integer">#{id}</id>
<name>#{name}</name>
<description>#{description}</description>
<project-id type="integer">#{project_id}</project-id>
<milestone-id type="integer">#{milestone_id}</milestone-id>
<position type="integer">#{position}</position>
<!-- if user can see private lists -->
<private type="boolean">#{private}</private>
<!-- if the account supports time tracking -->
<tracked type="boolean">#{tracked}</tracked>
<!-- if todo-items are included in the response -->
<todo-items type="array">
<todo-item>
...
</todo-item>
<todo-item>
...
</todo-item>
...
</todo-items>
</todo-list>
How would I go about using .NET's serialization library to deserialize this into C# objects?
Currently I'm using reflection and I map between the xml and my objects using the naming conventions.

Create a class for each element that has a property for each element and a List or Array of objects (use the created one) for each child element. Then call System.Xml.Serialization.XmlSerializer.Deserialize on the string and cast the result as your object. Use the System.Xml.Serialization attributes to make adjustments, like to map the element to your ToDoList class, use the XmlElement("todo-list") attribute.
A shourtcut is to load your XML into Visual Studio, click the "Infer Schema" button and run "xsd.exe /c schema.xsd" to generate the classes. xsd.exe is in the tools folder. Then go through the generated code and make adjustments, such as changing shorts to ints where appropriate.

Boils down to using xsd.exe from tools in VS:
xsd.exe "%xsdFile%" /c /out:"%outDirectory%" /l:"%language%"
Then load it with reader and deserializer:
public GeneratedClassFromXSD GetObjectFromXML()
{
var settings = new XmlReaderSettings();
var obj = new GeneratedClassFromXSD();
var reader = XmlReader.Create(urlToService, settings);
var serializer = new System.Xml.Serialization.XmlSerializer(typeof(GeneratedClassFromXSD));
obj = (GeneratedClassFromXSD)serializer.Deserialize(reader);
reader.Close();
return obj;
}

Deserialize any object, as long as the type T is marked Serializable:
function T Deserialize<T>(string serializedResults)
{
var serializer = new XmlSerializer(typeof(T));
using (var stringReader = new StringReader(serializedResults))
return (T)serializer.Deserialize(stringReader);
}

Well, you'd have to have classes in your assembly that match, roughly, the XML (property called Private, a collection property called ToDo, etc).
The problem is that the XML has elements that are invalid for class names. So you'd have to implement IXmlSerializable in these classes to control how they are serialized to and from XML. You might be able to get away with using some of the xml serialization specific attributes as well, but that depends on your xml's schema.
That's a step above using reflection, but it might not be exactly what you're hoping for.

Checkout http://xsd2code.codeplex.com/
Xsd2Code is a CSharp or Visual Basic Business Entity class Generator from XSD schema.

There are a couple different options.
Visual Studio includes a command line program called xsd.exe. You use that program to create a schema document, and use the program again on the schema document to creates classes you can use with system.xml.serialization.xmlserializer
You might just be able to call Dataset.ReadXml() on it.

i had the same questions few years back that how abt mapping xml to C# classes or creating C# classes which are mapped to our XMLs, jst like we do in entity Framework (we map tables to C# classes). I created a framework finally, which can create C# classes out of your XML and these classes can be used to read/write your xml. Have a look