Updates the DefaultRenderingEngine in the umbracoSettings.config file

UpdateRenderingEngineToMvc

public class UpdateRenderingEngineToMvc()
{
  //Local variables
  var path = GlobalSettings.FullpathToRoot + Path.DirectorySeparatorChar + "config" + Path.DirectorySeparatorChar;
  var filePath = path + "umbracoSettings.config";
  var value = RenderingEngine.Mvc;
  
  //Load the config file as xml
  var xml = new XmlDocument();
  var settingsReader = new XmlTextReader(filePath);
  xml.Load(settingsReader);
  
  //Find the correct node for the 'defaultRenderingEngine' and update the value
  var node = xml.DocumentElement.SelectSingleNode("/settings/templates/defaultRenderingEngine");
  node.InnerText = value.ToString();
  xml.Save(filePath);
}