/// <summary>
/// Serializes the given graph to the given stream using TriX data format.
/// </summary>
internal static void Serialize(RDFGraph graph, Stream outputStream)
{
try
{
#region serialize
using (XmlTextWriter trixWriter = new XmlTextWriter(outputStream, Encoding.UTF8))
{
XmlDocument trixDoc = new XmlDocument();
trixWriter.Formatting = Formatting.Indented;
#region xmlDecl
XmlDeclaration trixDecl = trixDoc.CreateXmlDeclaration("1.0", "UTF-8", null);
trixDoc.AppendChild(trixDecl);
#endregion
#region trixRoot
XmlNode trixRoot = trixDoc.CreateNode(XmlNodeType.Element, "TriX", null);
XmlAttribute trixRootNS = trixDoc.CreateAttribute("xmlns");
XmlText trixRootNSText = trixDoc.CreateTextNode("http://www.w3.org/2004/03/trix/trix-1/");
trixRootNS.AppendChild(trixRootNSText);
trixRoot.Attributes.Append(trixRootNS);
#region graph
XmlNode graphElement = trixDoc.CreateNode(XmlNodeType.Element, "graph", null);
XmlNode graphUriElement = trixDoc.CreateNode(XmlNodeType.Element, "uri", null);
XmlText graphUriElementT = trixDoc.CreateTextNode(graph.ToString());
graphUriElement.AppendChild(graphUriElementT);
graphElement.AppendChild(graphUriElement);
#region triple
foreach (var t in graph)
{
XmlNode tripleElement = trixDoc.CreateNode(XmlNodeType.Element, "triple", null);
#region subj
XmlNode subjElement = (((RDFResource)t.Subject).IsBlank ? trixDoc.CreateNode(XmlNodeType.Element, "id", null) :
trixDoc.CreateNode(XmlNodeType.Element, "uri", null));
XmlText subjElementText = trixDoc.CreateTextNode(t.Subject.ToString());
subjElement.AppendChild(subjElementText);
tripleElement.AppendChild(subjElement);
#endregion
#region pred
XmlNode uriElementP = trixDoc.CreateNode(XmlNodeType.Element, "uri", null);
XmlText uriTextP = trixDoc.CreateTextNode(t.Predicate.ToString());
uriElementP.AppendChild(uriTextP);
tripleElement.AppendChild(uriElementP);
#endregion
#region object
if (t.TripleFlavor == RDFModelEnums.RDFTripleFlavors.SPO)
{
XmlNode objElement = (((RDFResource)t.Object).IsBlank ? trixDoc.CreateNode(XmlNodeType.Element, "id", null) :
trixDoc.CreateNode(XmlNodeType.Element, "uri", null));
XmlText objElementText = trixDoc.CreateTextNode(t.Object.ToString());
objElement.AppendChild(objElementText);
tripleElement.AppendChild(objElement);
}
#endregion
#region literal
else
{
#region plain literal
if (t.Object is RDFPlainLiteral)
{
XmlNode plainLiteralElement = trixDoc.CreateNode(XmlNodeType.Element, "plainLiteral", null);
if (((RDFPlainLiteral)t.Object).Language != string.Empty)
{
XmlAttribute xmlLang = trixDoc.CreateAttribute(string.Concat(RDFVocabulary.XML.PREFIX, ":lang"), RDFVocabulary.XML.BASE_URI);
XmlText xmlLangText = trixDoc.CreateTextNode(((RDFPlainLiteral)t.Object).Language);
xmlLang.AppendChild(xmlLangText);
plainLiteralElement.Attributes.Append(xmlLang);
}
XmlText plainLiteralText = trixDoc.CreateTextNode(RDFModelUtilities.EscapeControlCharsForXML(HttpUtility.HtmlDecode(((RDFLiteral)t.Object).Value)));
plainLiteralElement.AppendChild(plainLiteralText);
tripleElement.AppendChild(plainLiteralElement);
}
#endregion
#region typed literal
else
{
XmlNode typedLiteralElement = trixDoc.CreateNode(XmlNodeType.Element, "typedLiteral", null);
XmlAttribute datatype = trixDoc.CreateAttribute("datatype");
XmlText datatypeText = trixDoc.CreateTextNode(RDFModelUtilities.GetDatatypeFromEnum(((RDFTypedLiteral)t.Object).Datatype));
datatype.AppendChild(datatypeText);
typedLiteralElement.Attributes.Append(datatype);
XmlText typedLiteralText = trixDoc.CreateTextNode(RDFModelUtilities.EscapeControlCharsForXML(HttpUtility.HtmlDecode(((RDFLiteral)t.Object).Value)));
typedLiteralElement.AppendChild(typedLiteralText);
tripleElement.AppendChild(typedLiteralElement);
}
#endregion
}
#endregion
graphElement.AppendChild(tripleElement);
}
#endregion
trixRoot.AppendChild(graphElement);
#endregion
trixDoc.AppendChild(trixRoot);
#endregion
trixDoc.Save(trixWriter);
}
#endregion
}
catch (Exception ex)
{
throw new RDFModelException("Cannot serialize TriX because: " + ex.Message, ex);
}
}