XMLTextReader - Pass to XDocument.Load and interact

Question

I am loading an XML file into an XDocument like so:

XDocument oXDocument = XDocument.Load(m_sFile);

I want to know if I pass the Load method of the XDocument an XmlTextReader object in the manner shown below, can I interact with the loading mechanism using the XmlTextReader as if I were to use the Read method of XmlTextReader in a conventional manner?

Conventional XmlTextReader use
-------------------------------

        oReader = new XmlTextReader(m_sFile);
        while (oReader.Read())
        {
                switch (oReader.NodeType)
                {
                        case XmlNodeType.Element:

                                //DO SOMETHING

                                break;
                }
        }

Passing the XmlTextReader
-------------------------

            using (XmlTextReader oXMLTextReader = new XmlTextReader(m_sFile))
            {
                oXMLTextReader.MoveToContent();
                oXDocument = XDocument.Load(oXMLTextReader);
            }

Any help is most welcome.

Vulpes · Answer

I've been thinking some more about this and you should be able to populate an XDocument dynamically using XNode.ReadFrom() and an XmlTextReader rather than XDocument.Load(). Suppose for example we have this persons.xml file: Barack Obama New York David Cameron London Nicolas Sarkozy Paris Then the following code if I've written it correctly should create an XDocument using just the first Person node (ignoring the other two) and change the content of the Address node from New York to Washington: using System; using System.Xml; using System.Xml.Linq; class Program { static void Main() { string m_sFile = persons.xml; var persons = new XElement(Persons); XElement person = null; var settings = new XmlReaderSettings(); settings.IgnoreWhitespace = true; using (var oReader = XmlTextReader.Create(m_sFile settings)) { oReader.ReadStartElement(Persons); int count = 1; while (oReader.Name == Person) { person = (XElement)XNode.ReadFrom(oReader); person.Element(Address).Value = Washington; if (count == 1) persons.Add(person); count++; } oReader.ReadEndElement(); } var doc = new XDocument(); doc.Add(persons); Console.WriteLine(doc); Console.ReadKey(); } } In practice of course you could do any manipulations you like as the file is read.

Suthish Nair · Answer

If the query got resolved then mark the post that helped you as Answer so will be helpful for others. Otherwise if you got the solution please share with us.

Mark Maguire · Answer

Thanks again Vulpes I've managed to get my file to dynamically load in. I ended up implementing the ReadSubTree method which creates an XMLReader this allowed me to recursively iterate all the child nodes (regardless of how deep they are) and manipulate the data as it loads. It also now allows me to implement progress information. Thanks for your help!

Suthish Nair · Answer

http://www.c-sharpcorner.com/UploadFile/Blogs/4073/

Vulpes · Answer

Oops I was looking at the documentation for XDocument.CreateReader() which returns an XmlReader reference (apparently a System.Xml.Linq.XNodeReader object in reality) and I think I read the inheritance tree the wrong way up! However as far as I can see that's the only way to get any sort of reader out of XDocument.

Mark Maguire · Answer

Thanks Vulpes This does not work for me as the data is loaded first before reaching the line stating: XmlTextReader oReader = ( XmlTextReader )oXDocument.CreateReader(); This line also fails to cast an XNodeReader to an XmlTextReader. I need to be able to interact with the load method as it executes in some way either that or dynamically populate the XDocument using the XmlTextReader without using the XDocument.Load method. Any more ideas? Cheers

Vulpes · Answer

You should be able to do this: oXDocument = XDocument.Load(oXMLTextReader); XmlTextReader oReader = (XmlTextReader)oXDocument.CreateReader(); while (oReader.Read()) { // etc }