Question

I receive a an xml string from third party. The xml string contains invalid characters like & and ‘. I am trying to put it in dataset (ASP.NET). it throws error. Can anyone pls help.

Answer 1

Tell/ask the third party to provide valid XML.

Interoperability standards don’t count for much when they aren’t adhered to. If they are passing you invalid characters today, what’s to stop them from passing mismatched nodes tomorrow? or no tags at all?

If there is no standard, then there are an endless number of scenarios for which you might need to code around.

That said, you can:

• Ensure that it is not a problem in your code (post code if you want specifics).
• Create a configurable list of known find/replace scenarios and pre-process your input “XML” string.
• If data integrity isn’t important (personally, I think it always is), you can load your data into an HTML parser, which will be far more forgiving and allow XML DOM-like document access.

Per the OP’s comment, here is a very, very simple example of a somewhat configurable find/replace.

public string PreProcessXml( string xml )
{
    // this list could be read from a config file

    List<Tuple<string, string>> replacements = new List<Tuple<string, string>>();

    // Important: if there are VALID uses of an ampersand in your document, 
    // this may invalidate them! Perform a more elaborate check using a 
    // regex, or ensure that there are no valid entities already in the document.
    replacements.Add( new Tuple<string, string>( "&", "&amp;" ) );

    replacements.Add( new Tuple<string, string>( "\"", "&quot;" ) );
    replacements.Add( new Tuple<string, string>( "\'", "&apos;" ) );

    foreach( var replacement in replacements )
    {
        xml = xml .Replace( replacement.Item1, replacement.Item2 );
    }

     return xml;
}