Creating a XML Document from scratch without using a file in C#

Creating
a XML Document from scratch without using a file in C#

April 4, 2007

One thing that’s annoying is that
majority of the XML example assumes that you are loading an XML document
from a file, so here’s a simple code example for generating it entirely
in memory.

// Create the xml document containe

XmlDocument doc = new XmlDocument();

// Create the XML
Declaration, and append it to XML document

XmlDeclaration dec = doc.CreateXmlDeclaration("1.0", null, null);

doc.AppendChild(dec);

// Create the root element

XmlElement root = doc.CreateElement("Library");

doc.AppendChild(root);

// Create Books

// Note that to set the text inside the element,

// you use .InnerText instead of .Value (which will throw an exception).

// You use SetAttribute to set attribute

XmlElement book = doc.CreateElement("Book");

book.SetAttribute("BookType", "Hardcover");

XmlElement title = doc.CreateElement("Title");

title.InnerText = "Door Number Three";

XmlElement author = doc.CreateElement("Author");

author.InnerText = "O'Leary, Patrick";

book.AppendChild(title);

book.AppendChild(author);

root.AppendChild(book);

book = doc.CreateElement("Book");

book.SetAttribute("BookType", "Paperback");

title = doc.CreateElement("Title");

title.InnerText = "Lord of Light";

author = doc.CreateElement("Author");

author.InnerText = "Zelanzy, Roger";

book.AppendChild(title);

book.AppendChild(author);

root.AppendChild(book);

string xmlOutput = doc.OuterXml;

The same code but using an XMLWriter to a memory stream.

XmlWriterSettings wSettings = new XmlWriterSettings();

wSettings.Indent = true;

MemoryStream ms = new MemoryStream();

XmlWriter xw = XmlWriter.Create(ms, wSettings);

// Write
Declaration

xw.WriteStartDocument();

// Write the root node

xw.WriteStartElement("Library");

// Write the books and the book elements

xw.WriteStartElement("Book");

xw.WriteStartAttribute("BookType");

xw.WriteString("Hardback");

xw.WriteEndAttribute();

xw.WriteStartElement("Title");

xw.WriteString("Door Number Three");

xw.WriteEndElement();

xw.WriteStartElement("Author");

xw.WriteString("O'Leary, Patrick");

xw.WriteEndElement();

xw.WriteEndElement();

// Write another book

xw.WriteStartElement("Book");

xw.WriteStartAttribute("BookType");

xw.WriteString("Paperback");

xw.WriteEndAttribute();

xw.WriteStartElement("Title");

xw.WriteString("Lord of Light");

xw.WriteEndElement();

xw.WriteStartElement("Author");

xw.WriteString("Zelanzy, Roger");

xw.WriteEndElement();

xw.WriteEndElement();

// Close the document

xw.WriteEndDocument();

// Flush the write

xw.Flush();

Byte[] buffer = new Byte[ms.Length];

buffer = ms.ToArray();

string xmlOutput = System.Text.Encoding.UTF8.GetString(buffer);

-------------------------------------------------------------------------------------------------------------------------------

Create a New XML File Using XmlDocument
Here's the XML File:

<?xml version="1.0" encoding="utf-8"?>

<CategoryList>

<Category ID="01">

<MainCategory>XML</MainCategory>

<Description>This is a list my XML articles.</Description>

<Active>true</Active>

</Category>

</CategoryList>

[/code]
Here's the code:

<%@ Import Namespace="System.Data" %>

<%@ Import Namespace="System.Xml" %>

<%@ Page Language="C#" Debug="true" %>

<script  runat="server">

void Page_Load(object sender, System.EventArgs e){

if(!Page.IsPostBack){

XmlDocument xmlDoc = new XmlDocument();

// Write down the XML declaration

XmlDeclaration xmlDeclaration = xmlDoc.CreateXmlDeclaration("1.0","utf-8",null);

// Create the root element

XmlElement rootNode  = xmlDoc.CreateElement("CategoryList");

xmlDoc.InsertBefore(xmlDeclaration, xmlDoc.DocumentElement);

xmlDoc.AppendChild(rootNode);

// Create a new <Category> element and add it to the root node

XmlElement parentNode  = xmlDoc.CreateElement("Category");

// Set attribute name and value!

parentNode.SetAttribute("ID", "01");

xmlDoc.DocumentElement.PrependChild(parentNode);

// Create the required nodes

XmlElement mainNode  = xmlDoc.CreateElement("MainCategory");

XmlElement descNode  = xmlDoc.CreateElement("Description");

XmlElement activeNode  = xmlDoc.CreateElement("Active");

// retrieve the text

XmlText categoryText= xmlDoc.CreateTextNode("XML");

XmlText descText  = xmlDoc.CreateTextNode("This is a list my XML articles.");

XmlText activeText  = xmlDoc.CreateTextNode("true");

// append the nodes to the parentNode without the value

parentNode.AppendChild(mainNode);

parentNode.AppendChild(descNode);

parentNode.AppendChild(activeNode);

// save the value of the fields into the nodes

mainNode.AppendChild(categoryText);

descNode.AppendChild(descText);

activeNode.AppendChild(activeText);

// Save to the XML file

xmlDoc.Save( Server.MapPath("categories.xml"));

Response.Write("XML file created");

}

}

</script>

[/code]