XmlResolver.cs

using System.IO;
using System.Net;
using System.Threading.Tasks;

namespace System.Xml
{
    public abstract class XmlResolver
    {
        public virtual ICredentials Credentials
        {
            set
            {
            }
        }

        public abstract object GetEntity(Uri absoluteUri, string role, Type ofObjectToReturn);

        public virtual Uri ResolveUri(Uri baseUri, string relativeUri)
        {
            if (baseUri == null || (!baseUri.IsAbsoluteUri && baseUri.OriginalString.Length == 0))
            {
                Uri uri = new Uri(relativeUri, UriKind.RelativeOrAbsolute);
                if (!uri.IsAbsoluteUri && uri.OriginalString.Length > 0)
                {
                    uri = new Uri(Path.GetFullPath(relativeUri));
                }
                return uri;
            }
            if (relativeUri == null || relativeUri.Length == 0)
            {
                return baseUri;
            }
            if (!baseUri.IsAbsoluteUri)
            {
                throw new NotSupportedException(Res.GetString("Xml_RelativeUriNotSupported"));
            }
            return new Uri(baseUri, relativeUri);
        }

        public virtual bool SupportsType(Uri absoluteUri, Type type)
        {
            if (absoluteUri == null)
            {
                throw new ArgumentNullException("absoluteUri");
            }
            if (type == null || type == typeof(Stream))
            {
                return true;
            }
            return false;
        }

        public virtual Task<object> GetEntityAsync(Uri absoluteUri, string role, Type ofObjectToReturn)
        {
            throw new NotImplementedException();
        }
    }
}