XDocument: saving XML to file without BOM

Question

I\'m generating an utf-8 XML file using XDocument.

XDocument xml_document = new XDocument(
                    new XDeclaration(\"1.0\"         


        

Answer 1

First of all: the service provider MUST handle it, according to XML spec, which states that BOM may be present in case of UTF-8 representation.

You can force to save your XML without BOM like this:

XmlWriterSettings settings = new XmlWriterSettings();
settings.Encoding = new UTF8Encoding(false); // The false means, do not emit the BOM.
using (XmlWriter w = XmlWriter.Create("my.xml", settings))
{
    doc.Save(w);
}

(Googled from here: http://social.msdn.microsoft.com/Forums/en/xmlandnetfx/thread/ccc08c65-01d7-43c6-adf3-1fc70fdb026a)

Answer 2

Use an XmlTextWriter and pass that to the XDocument's Save() method, that way you can have more control over the type of encoding used:

var doc = new XDocument(
    new XDeclaration("1.0", "utf-8", null),
    new XElement("root", new XAttribute("note", "boogers"))
);
using (var writer = new XmlTextWriter(".\\boogers.xml", new UTF8Encoding(false)))
{
    doc.Save(writer);
}

The UTF8Encoding class constructor has an overload that specifies whether or not to use the BOM (Byte Order Mark) with a boolean value, in your case false.

The result of this code was verified using Notepad++ to inspect the file's encoding.

Answer 3

The most expedient way to get rid of the BOM character when using XDocument is to just save the document, then do a straight File read as a file, then write it back out. The File routines will strip the character out for you:

        XDocument xTasks = new XDocument();
        XElement xRoot = new XElement("tasklist",
            new XAttribute("timestamp",lastUpdated),
            new XElement("lasttask",lastTask)
        );
        ...
        xTasks.Add(xRoot);
        xTasks.Save("tasks.xml");

        // read it straight in, write it straight back out. Done.
        string[] lines = File.ReadAllLines("tasks.xml");
        File.WriteAllLines("tasks.xml",lines);

(it's hoky, but it works for the sake of expediency - at least you'll have a well-formed file to upload to your online provider) ;)