This is a collaboration of msdn and blog postings.
XDocument document;
using (var stringReader = new StringReader(output))
{
var settings = new XmlReaderSettings
{
ProhibitDtd = false,
XmlResolver = new LocalXhtmlXmlResolver(bool.Parse(ConfigurationManager.AppSettings["CacheDTDs"]))
};
document = XDocument.Load(XmlReader.Create(stringReader, settings));
}
private class LocalXhtmlXmlResolver : XmlUrlResolver
{
private static readonly Dictionary<string, Uri> KnownUris = new Dictionary<string, Uri>
{
{ "-//W3C//DTD XHTML 1.0 Strict//EN", new Uri("http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd") },
{ "-//W3C XHTML 1.0 Transitional//EN", new Uri("http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd") },
{ "-//W3C//DTD XHTML 1.0 Transitional//EN", new Uri("http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd") },
{ "-//W3C XHTML 1.0 Frameset//EN", new Uri("http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd") },
{ "-//W3C//DTD XHTML 1.1//EN", new Uri("http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd") }
};
private bool enableHttpCaching;
private ICredentials credentials;
public LocalXhtmlXmlResolver(bool enableHttpCaching)
{
this.enableHttpCaching = enableHttpCaching;
}
public override Uri ResolveUri(Uri baseUri, string relativeUri)
{
Debug.WriteLineIf(!KnownUris.ContainsKey(relativeUri), "Could not find: " + relativeUri);
return KnownUris.ContainsKey(relativeUri) ? KnownUris[relativeUri] : base.ResolveUri(baseUri, relativeUri);
}
public override object GetEntity(Uri absoluteUri, string role, Type ofObjectToReturn)
{
if (absoluteUri == null)
{
throw new ArgumentNullException("absoluteUri");
}
//resolve resources from cache (if possible)
if (absoluteUri.Scheme == "http" && this.enableHttpCaching && (ofObjectToReturn == null || ofObjectToReturn == typeof(Stream)))
{
var request = WebRequest.Create(absoluteUri);
request.CachePolicy = new HttpRequestCachePolicy(HttpRequestCacheLevel.Default);
if (this.credentials != null)
{
request.Credentials = this.credentials;
}
var response = request.GetResponse();
return response.GetResponseStream();
}
//otherwise use the default behavior of the XmlUrlResolver class (resolve resources from source)
return base.GetEntity(absoluteUri, role, ofObjectToReturn);
}
}
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