C# XMLWriter + prevent "/" "<" "<" chars

Question

Hello,

I have a xmlWriter and want to write String which containt chars of "/" "<" ">" (which are part of the xml syntax and break the xml code). Here is my c# code:

public Boolean Initialize(String path)
    {
        Boolean result = true;

            XmlWriterSettings settings = new XmlWriterSettings();
            settings.CheckCharacters = true;
            settings.Encoding = Encoding.UTF8;
            settings.Indent = true;

            xmlWriter = XmlWriter.Create(path, settings);

            xmlWriter.WriteStartDocument();
            xmlWriter.WriteStartElement("TestData");
            isInitialized = true;

        return result;
    }

public void WriteProducts(List<Product> productList)
    {
        if (isInitialized == true)
        {
            foreach (Product product in productList)
            {
                xmlWriter.WriteStartElement("Product");

                xmlWriter.WriteElementString("Id", product.ProdId);
                xmlWriter.WriteElementString("Name", product.ProdName);
                xmlWriter.WriteElementString("GroupId", product.ProdGroup);
                xmlWriter.WriteElementString("Price", product.ProdPrice.ToString((Consts.FORMATTED_PRICE)));

                xmlWriter.WriteEndElement();
            }
        }
    }

public void Close()
    {
        xmlWriter.WriteEndElement();
        xmlWriter.WriteEndDocument();
    }

The application runs without any errors, but if I look in the xml file, the xml is incomplete because the xmlwriter stops writing the product nodes when a product name contains one of the above mentioned characters.

Is there a way to fix this problem?

Answer 1

You could either use WriteRaw or enclose the content in <![CDATA[ content goes here ]]>

Answer 2

You could use the Server.HtmlEncode(string) method from the System.Web.HttpServerUtility class (this will require you to add the assembly), which will transform < to < (for instance)

And then use Server.HtmlDecode(string) to transform < back to <

Answer 3

You need to re-organize your code a little, and use WriteString to write the values, as this encodes "special" characters:

use http://msdn.microsoft.com/en-us/library/system.xml.xmltextwriter.writestring.aspx

When the Xml is read back (with an Xml reader) the encoded characters will be decoded.

Answer 4

If it is for example product.ProdName that can contain those chars you can do this:

xmlWriter.WriteStartElement("Product");

xmlWriter.WriteElementString("Id", product.ProdId);

xmlWriter.WriteStartElement("Name");
xmlWriter.WriteString(product.ProdName); // or xmlWriter.WriteCData(product.ProdName);
xmlWriter.WriteEndElement();

xmlWriter.WriteElementString("GroupId", product.ProdGroup);
xmlWriter.WriteElementString("Price", product.ProdPrice.ToString((Consts.FORMATTED_PRICE)));

xmlWriter.WriteEndElement();