When you have multiple Form Content Types with each their respective form templates assigned to the same Form Library by some magic it will automatically save a new form in the correct Content Type. How it does this ?
The new form’s XML contains an InfoPath processing instruction with a “href” attribute set to the XSN template URL. At save time the Content Types configured in the Form Library are iterated and a match is made based on Template URL. If no match is found it will use the default Content Type.
Even works in code if you do a SPFileCollection.Add() so no need to specify the Content Type explicitly during saves !
It doesn’t seem to take Alternate Access Mappings into account so that’s a bit of a downer, but still powerful.
Using xsd.exe you can generate a Class from your form schema (xsd) and then deserialize a form to an instance of that class. This makes it a lot easier to interact with its data.
The code for serialization and deserialization might look like this:
public static T Deserialize<T>(Stream s)
{
T result = default(T);
XmlSerializer serializer = new XmlSerializer(typeof(T));
using (XmlTextReader reader = new XmlTextReader(s))
{
result = (T)serializer.Deserialize(reader);
}
s.Close();
return result;
}
public static T Deserialize<T>(string s)
{
return Deserialize<T>(new MemoryStream(Encoding.UTF8.GetBytes(s)));
}
public static string Serialize<T>(T o)
{
string result = null;
XmlSerializer serializer = new XmlSerializer(typeof(T));
XmlWriterSettings settings = new XmlWriterSettings();
settings.Indent = true;
settings.Encoding = Encoding.UTF8;
using (MemoryStream stream = new MemoryStream())
{
using (XmlWriter writer = XmlTextWriter.Create(stream, settings))
{
serializer.Serialize(writer, o);
}
stream.Flush();
result = Encoding.UTF8.GetString(stream.ToArray());
}
return result;
}
However you lose the original processing instructions at the top of the XML file. If you want to keep those either do custom serialization using an XmlWriter or do some kind of merge code with the original XML and the XML coming from serialization.
Quite obvious if you think about it but I keep forgetting it :)