Question

I’m currently working on a Windows Phone 7 Application for the company I work for. For the configuration part I’d like to share the configuration that is used for our iPhone Application and stored on a remote server in a plist file.

I use System.Xml.Linq.XDocument to Parse a string I downloaded using a WebClient instance.

This is the code:

        Uri plistLocation = new 
            Uri(@"http://iphonevnreporter.vol.at/Settings.bundle/mw_test.plist");
        WebClient client = new WebClient();

        try
        {
            client.DownloadStringCompleted += ((sender,e) => {
                if (e.Error == null)
                {
                    XDocument xdoc = XDocument.Parse(e.Result);

                    //XElement element = XElement.Parse(e.Result.ToString());
                    var dictItems = xdoc.Descendants("dict");
                    foreach (XElement elem in dictItems)
                    {
                    }
                }
            });
        }
        catch (Exception e)
        {
        }
        client.DownloadStringAsync(plistLocation);

In this example the plist is just having a dict Element under the root plist element and nevertheless I am receiving the NotSupportedException. The Exception occurs at XDocument.Parse(e.Result).

This is the StackTrace:

   at System.Xml.XmlTextReaderImpl.ParseDoctypeDecl()
   at System.Xml.XmlTextReaderImpl.ParseDocumentContent()
   at System.Xml.XmlTextReaderImpl.Read()
   at System.Xml.Linq.XDeclaration..ctor(XmlReader r)
   at System.Xml.Linq.XDocument.Load(XmlReader reader, LoadOptions options)
   at System.Xml.Linq.XDocument.Parse(String text, LoadOptions options)
   at System.Xml.Linq.XDocument.Parse(String text)
   at VorarlbergOnline.MainViewModel.<FillSections>b__10(
                 Object sender, DownloadStringCompletedEventArgs e)
   at System.Net.WebClient.OnDownloadStringCompleted
            (DownloadStringCompletedEventArgs     e)
   at System.Net.WebClient.DownloadStringOperationCompleted(Object arg)
   at System.Threading.ThreadPool.WorkItem.WaitCallback_Context(Object state)
   at System.Threading.ExecutionContext.Run(ExecutionContext 
        executionContext,     ContextCallback callback, Object state)
   at System.Threading.ThreadPool.WorkItem.doWork(Object o)
   at System.Threading.Timer.ring()

Loading other XML files works fine, so the code seems to be ok. I checked if the referenced dtd could be the problem, but it loads fine. So I’m kind of out of ideas now.

Answer 1

Okay, now I’ve actually looked at the file in the raw rather than via a browser, I’m sure this is the problem:

<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" 
          "http://www.apple.com/DTDs/PropertyList-1.0.dtd">

It looks like doctype parsing just isn’t supported in Windows Phone 7. You could do a quick and dirty hack to remove it though:

string xml = e.Result;
int docTypeIndex = xml.IndexOf("<!DOCTYPE");
if (docTypeIndex != -1)
{
    int docTypeEnd = xml.IndexOf(">", docTypeIndex);
    // TODO: Decide what to do if docTypeEnd is -1...
    xml = xml.Substring(0, docTypeIndex) + xml.Substring(docTypeEnd + 1);
}