private string GenerateNodeOutput(INode node, TripleSegment segment)
{
switch (node.NodeType)
{
case NodeType.Blank:
if (segment == TripleSegment.Predicate)
{
throw new RdfOutputException(WriterErrorMessages.BlankPredicatesUnserializable("Turtle"));
}
return(Format(node, segment));
case NodeType.Uri:
return(Format(node, segment));
case NodeType.Literal:
if (segment == TripleSegment.Subject)
{
throw new RdfOutputException(WriterErrorMessages.LiteralSubjectsUnserializable("Turtle"));
}
if (segment == TripleSegment.Predicate)
{
throw new RdfOutputException(WriterErrorMessages.LiteralPredicatesUnserializable("Turtle"));
}
return(Format(node, segment));
case NodeType.GraphLiteral:
throw new RdfOutputException(WriterErrorMessages.GraphLiteralsUnserializable("Turtle"));
default:
throw new RdfOutputException(WriterErrorMessages.UnknownNodeTypeUnserializable("Turtle"));
}
}
/// <summary>
/// Formats a Triple as a <strong><rdf:Description></strong> element.
/// </summary>
/// <param name="t">Triple.</param>
/// <returns></returns>
public string Format(Triple t)
{
StringBuilder output = new StringBuilder();
output.Append("<rdf:Description ");
switch (t.Subject.NodeType)
{
case NodeType.Uri:
output.Append("rdf:about=\"" + WriterHelper.EncodeForXml(t.Subject.ToString()) + "\"");
break;
case NodeType.Blank:
output.Append("rdf:nodeID=\"" + ((IBlankNode)t.Subject).InternalID + "\"");
break;
case NodeType.Literal:
throw new RdfOutputException(WriterErrorMessages.LiteralSubjectsUnserializable("RDF/XML"));
case NodeType.GraphLiteral:
throw new RdfOutputException(WriterErrorMessages.GraphLiteralsUnserializable("RDF/XML"));
case NodeType.Variable:
throw new RdfOutputException(WriterErrorMessages.VariableNodesUnserializable("RDF/XML"));
default:
throw new RdfOutputException(WriterErrorMessages.UnknownNodeTypeUnserializable("RDF/XML"));
}
output.AppendLine(">");
String qname;
String ns;
switch (t.Predicate.NodeType)
{
case NodeType.Uri:
Uri u = ((IUriNode)t.Predicate).Uri;
GetQName(u, out qname, out ns);
output.Append('\t');
if (ns.Equals(String.Empty))
{
output.Append("<" + qname);
}
else
{
output.Append("<" + qname + " xmlns=\"" + WriterHelper.EncodeForXml(ns) + "\"");
}
break;
case NodeType.Blank:
throw new RdfOutputException(WriterErrorMessages.BlankPredicatesUnserializable("RDF/XML"));
case NodeType.Literal:
throw new RdfOutputException(WriterErrorMessages.LiteralPredicatesUnserializable("RDF/XML"));
case NodeType.GraphLiteral:
throw new RdfOutputException(WriterErrorMessages.GraphLiteralsUnserializable("RDF/XML"));
case NodeType.Variable:
throw new RdfOutputException(WriterErrorMessages.VariableNodesUnserializable("RDF/XML"));
default:
throw new RdfOutputException(WriterErrorMessages.UnknownNodeTypeUnserializable("RDF/XML"));
}
switch (t.Object.NodeType)
{
case NodeType.Blank:
output.AppendLine(" rdf:nodeID=\"" + ((IBlankNode)t.Object).InternalID + "\" />");
break;
case NodeType.GraphLiteral:
throw new RdfOutputException(WriterErrorMessages.GraphLiteralsUnserializable("RDF/XML"));
case NodeType.Literal:
ILiteralNode lit = (ILiteralNode)t.Object;
if (lit.DataType != null)
{
if (lit.DataType.ToString().Equals(RdfSpecsHelper.RdfXmlLiteral))
{
output.AppendLine(" rdf:parseType=\"Literal\">" + lit.Value + "</" + qname + ">");
}
else
{
output.AppendLine(" rdf:datatype=\"" + WriterHelper.EncodeForXml(lit.DataType.AbsoluteUri) + "\">" + WriterHelper.EncodeForXml(lit.Value) + "</" + qname + ">");
}
}
else if (!lit.Language.Equals(String.Empty))
{
output.AppendLine(" xml:lang=\"" + lit.Language + "\">" + WriterHelper.EncodeForXml(lit.Value) + "</" + qname + ">");
}
else
{
output.AppendLine(">" + WriterHelper.EncodeForXml(lit.Value) + "</" + qname + ">");
}
break;
case NodeType.Uri:
output.AppendLine(" rdf:resource=\"" + WriterHelper.EncodeForXml(t.Object.ToString()) + "\" />");
break;
case NodeType.Variable:
throw new RdfOutputException(WriterErrorMessages.VariableNodesUnserializable("RDF/XML"));
default:
throw new RdfOutputException(WriterErrorMessages.UnknownNodeTypeUnserializable("RDF/XML"));
}
output.Append("</rdf:Description>");
return(output.ToString());
}