Find and replace in XAML programatically

Question

I'm trying to programatically parse/search a XAML file for a certain node then a certain attribute to modify it. The XAML is a windows workflow so its not really user controls. I have found many examples using XamlReader to parse a Xaml file to look for controls and then modify the controls. But in my case I'm looking for custom activities which are not dependancyObjects. Can I use XamlReader to find custom activities in a windows workflow Xaml and modify certain attributes? Or is there a better solution?

Answer 1

You don't need to use XamlReader, use XmlDocument and walk through the elements and attributes.

Here's what we do, just write the "DoYourStringReplace" method:

private void ParseXml(
    TextWriter resultStream,
    TextReader sourceStream)
{
    XmlDocument doc = new XmlDocument();
    doc.PreserveWhitespace = true;
    doc.Load(sourceStream);
    ParseXmlNodes(doc.DocumentElement);

    using (XmlWriter xw = XmlWriter.Create(resultStream))
    {
        doc.WriteTo(xw);
    }
}

/// <summary>
/// Parse a single XML node and its children.
/// </summary>
/// <param name="node"></param>
private void ParseXmlNodes(XmlNode node)
{
    if (node.NodeType == XmlNodeType.Element)
    {
        //
        //  Replace tokens in XML attribute values
        //
        foreach (XmlAttribute a in node.Attributes)
        {
            a.Value = DoYourStringReplace(a.Value);
        }
    }
    else if (node.NodeType == XmlNodeType.Text)
    {
        //
        //  Replace tokens in the XML Element value
        //
        node.Value = DoYourStringReplace(node.Value);
    }

    //
    //  Do the same thing for all children
    //
    foreach (XmlNode child in node.ChildNodes)
    {
        ParseXmlNodes(child);
    }
}