/// <summary>
/// Internal method which generates the RDF/Json Output for a Graph
/// </summary>
/// <param name="context">Writer Context</param>
private void GenerateOutput(RdfXmlWriterContext context)
{
context.UseDtd = this._useDTD;
//Create required variables
int nextNamespaceID = 0;
List <String> tempNamespaces = new List <String>();
//Always force RDF Namespace to be correctly defined
context.Graph.NamespaceMap.AddNamespace("rdf", new Uri(NamespaceMapper.RDF));
//Create an XML Document
XmlDocument doc = new XmlDocument();
XmlDeclaration decl = doc.CreateXmlDeclaration("1.0", "UTF-8", null);
doc.AppendChild(decl);
//Create the DOCTYPE declaration and the rdf:RDF element
StringBuilder entities = new StringBuilder();
XmlElement rdf = doc.CreateElement("rdf:RDF", NamespaceMapper.RDF);
if (context.Graph.BaseUri != null)
{
XmlAttribute baseUri = doc.CreateAttribute("xml:base");
baseUri.Value = Uri.EscapeUriString(context.Graph.BaseUri.ToString());
rdf.Attributes.Append(baseUri);
}
XmlAttribute ns;
String uri;
entities.Append('\n');
foreach (String prefix in context.Graph.NamespaceMap.Prefixes)
{
uri = context.Graph.NamespaceMap.GetNamespaceUri(prefix).ToString();
if (!prefix.Equals(String.Empty))
{
entities.AppendLine("\t<!ENTITY " + prefix + " '" + uri + "'>");
ns = doc.CreateAttribute("xmlns:" + prefix);
ns.Value = Uri.EscapeUriString(uri.Replace("'", "'"));
}
else
{
ns = doc.CreateAttribute("xmlns");
ns.Value = Uri.EscapeUriString(uri);
}
rdf.Attributes.Append(ns);
}
if (context.UseDtd)
{
XmlDocumentType doctype = doc.CreateDocumentType("rdf:RDF", null, null, entities.ToString());
doc.AppendChild(doctype);
}
doc.AppendChild(rdf);
//Find the Collections
if (this._compressionLevel >= WriterCompressionLevel.More)
{
WriterHelper.FindCollections(context);
}
//Find the Type References
Dictionary <INode, String> typerefs = this.FindTypeReferences(context, ref nextNamespaceID, tempNamespaces, doc);
//Get the Triples as a Sorted List
List <Triple> ts = context.Graph.Triples.Where(t => !context.TriplesDone.Contains(t)).ToList();
ts.Sort();
//Variables we need to track our writing
INode lastSubj, lastPred;
lastSubj = lastPred = null;
XmlElement subj, pred;
//Initialise stuff to keep the compiler happy
subj = doc.CreateElement("rdf:Description", NamespaceMapper.RDF);
pred = doc.CreateElement("temp");
for (int i = 0; i < ts.Count; i++)
{
Triple t = ts[i];
if (context.TriplesDone.Contains(t))
{
continue; //Skip if already done
}
if (lastSubj == null || !t.Subject.Equals(lastSubj))
{
//Start a new set of Triples
//Validate Subject
//Use a Type Reference if applicable
if (typerefs.ContainsKey(t.Subject))
{
String tref = typerefs[t.Subject];
String tprefix;
if (tref.StartsWith(":"))
{
tprefix = String.Empty;
}
else if (tref.Contains(":"))
{
tprefix = tref.Substring(0, tref.IndexOf(':'));
}
else
{
tprefix = String.Empty;
}
subj = doc.CreateElement(tref, context.Graph.NamespaceMap.GetNamespaceUri(tprefix).ToString());
}
else
{
subj = doc.CreateElement("rdf:Description", NamespaceMapper.RDF);
}
//Write out the Subject
doc.DocumentElement.AppendChild(subj);
lastSubj = t.Subject;
//Apply appropriate attributes
switch (t.Subject.NodeType)
{
case NodeType.GraphLiteral:
throw new RdfOutputException(WriterErrorMessages.GraphLiteralsUnserializable("RDF/XML"));
case NodeType.Literal:
throw new RdfOutputException(WriterErrorMessages.LiteralSubjectsUnserializable("RDF/XML"));
case NodeType.Blank:
if (context.Collections.ContainsKey(t.Subject))
{
this.GenerateCollectionOutput(context, t.Subject, subj, ref nextNamespaceID, tempNamespaces, doc);
}
else
{
XmlAttribute nodeID = doc.CreateAttribute("rdf:nodeID", NamespaceMapper.RDF);
nodeID.Value = ((IBlankNode)t.Subject).InternalID;
subj.Attributes.Append(nodeID);
}
break;
case NodeType.Uri:
this.GenerateUriOutput(context, (IUriNode)t.Subject, "rdf:about", tempNamespaces, subj, doc);
break;
default:
throw new RdfOutputException(WriterErrorMessages.UnknownNodeTypeUnserializable("RDF/XML"));
}
//Write the Predicate
pred = this.GeneratePredicateNode(context, t.Predicate, ref nextNamespaceID, tempNamespaces, doc, subj);
subj.AppendChild(pred);
lastPred = t.Predicate;
}
else if (lastPred == null || !t.Predicate.Equals(lastPred))
{
//Write the Predicate
pred = this.GeneratePredicateNode(context, t.Predicate, ref nextNamespaceID, tempNamespaces, doc, subj);
subj.AppendChild(pred);
lastPred = t.Predicate;
}
//Write the Object
//Create an Object for the Object
switch (t.Object.NodeType)
{
case NodeType.Blank:
if (pred.HasChildNodes || pred.HasAttributes)
{
//Require a new Predicate
pred = this.GeneratePredicateNode(context, t.Predicate, ref nextNamespaceID, tempNamespaces, doc, subj);
subj.AppendChild(pred);
}
if (context.Collections.ContainsKey(t.Object))
{
//Output a Collection
this.GenerateCollectionOutput(context, t.Object, pred, ref nextNamespaceID, tempNamespaces, doc);
}
else
{
//Terminate the Blank Node triple by adding a rdf:nodeID attribute
XmlAttribute nodeID = doc.CreateAttribute("rdf:nodeID", NamespaceMapper.RDF);
nodeID.Value = ((IBlankNode)t.Object).InternalID;
pred.Attributes.Append(nodeID);
}
//Force a new Predicate after Blank Nodes
lastPred = null;
break;
case NodeType.GraphLiteral:
throw new RdfOutputException(WriterErrorMessages.GraphLiteralsUnserializable("RDF/XML"));
case NodeType.Literal:
ILiteralNode lit = (ILiteralNode)t.Object;
if (pred.HasChildNodes || pred.HasAttributes)
{
//Require a new Predicate
pred = this.GeneratePredicateNode(context, t.Predicate, ref nextNamespaceID, tempNamespaces, doc, subj);
subj.AppendChild(pred);
}
this.GenerateLiteralOutput(context, lit, pred, doc);
//Force a new Predicate Node after Literals
lastPred = null;
break;
case NodeType.Uri:
this.GenerateUriOutput(context, (IUriNode)t.Object, "rdf:resource", tempNamespaces, pred, doc);
//Force a new Predicate Node after URIs
lastPred = null;
break;
default:
throw new RdfOutputException(WriterErrorMessages.UnknownNodeTypeUnserializable("RDF/XML"));
}
context.TriplesDone.Add(t);
}
//Check we haven't failed to output any collections
foreach (KeyValuePair <INode, OutputRdfCollection> pair in context.Collections)
{
if (!pair.Value.HasBeenWritten)
{
if (typerefs.ContainsKey(pair.Key))
{
String tref = typerefs[pair.Key];
String tprefix;
if (tref.StartsWith(":"))
{
tref = tref.Substring(1);
tprefix = String.Empty;
}
else if (tref.Contains(":"))
{
tprefix = tref.Substring(0, tref.IndexOf(':'));
}
else
{
tprefix = String.Empty;
}
subj = doc.CreateElement(tref, context.Graph.NamespaceMap.GetNamespaceUri(tprefix).ToString());
doc.DocumentElement.AppendChild(subj);
this.GenerateCollectionOutput(context, pair.Key, subj, ref nextNamespaceID, tempNamespaces, doc);
}
else
{
//Generate an rdf:Description Node with a rdf:nodeID on it
XmlElement colNode = doc.CreateElement("rdf:Description");
XmlAttribute nodeID = doc.CreateAttribute("rdf:nodeID");
nodeID.Value = ((IBlankNode)pair.Key).InternalID;
colNode.Attributes.Append(nodeID);
doc.DocumentElement.AppendChild(colNode);
this.GenerateCollectionOutput(context, pair.Key, colNode, ref nextNamespaceID, tempNamespaces, doc);
//throw new RdfOutputException("Failed to output a Collection due to an unknown error");
}
}
}
//Save to the Output Stream
InternalXmlWriter writer = new InternalXmlWriter();
writer.Save(context.Output, doc);
//Get rid of the Temporary Namespace
foreach (String tempPrefix in tempNamespaces)
{
context.Graph.NamespaceMap.RemoveNamespace(tempPrefix);
}
}
/// <summary>
/// Internal method which generates the RDF/Json Output for a Graph
/// </summary>
/// <param name="context">Writer Context</param>
private void GenerateOutput(RdfXmlWriterContext context)
{
context.UseDtd = this._useDTD;
//Create required variables
int nextNamespaceID = 0;
List<String> tempNamespaces = new List<String>();
//Always force RDF Namespace to be correctly defined
context.Graph.NamespaceMap.AddNamespace("rdf", new Uri(NamespaceMapper.RDF));
//Create an XML Document
XmlDocument doc = new XmlDocument();
XmlDeclaration decl = doc.CreateXmlDeclaration("1.0", "UTF-8", null);
doc.AppendChild(decl);
//Create the DOCTYPE declaration and the rdf:RDF element
StringBuilder entities = new StringBuilder();
XmlElement rdf = doc.CreateElement("rdf:RDF", NamespaceMapper.RDF);
if (context.Graph.BaseUri != null)
{
XmlAttribute baseUri = doc.CreateAttribute("xml:base");
baseUri.Value = context.Graph.BaseUri.ToString();
rdf.Attributes.Append(baseUri);
}
XmlAttribute ns;
String uri;
entities.Append('\n');
foreach (String prefix in context.Graph.NamespaceMap.Prefixes)
{
uri = context.Graph.NamespaceMap.GetNamespaceUri(prefix).ToString();
if (!prefix.Equals(String.Empty))
{
entities.AppendLine("\t<!ENTITY " + prefix + " '" + uri + "'>");
ns = doc.CreateAttribute("xmlns:" + prefix);
ns.Value = uri.Replace("'", "'");
}
else
{
ns = doc.CreateAttribute("xmlns");
ns.Value = uri;
}
rdf.Attributes.Append(ns);
}
if (context.UseDtd)
{
XmlDocumentType doctype = doc.CreateDocumentType("rdf:RDF", null, null, entities.ToString());
doc.AppendChild(doctype);
}
doc.AppendChild(rdf);
//Find the Collections
if (this._compressionLevel >= WriterCompressionLevel.More)
{
WriterHelper.FindCollections(context);
}
//Find the Type References
Dictionary<INode, String> typerefs = this.FindTypeReferences(context, ref nextNamespaceID, tempNamespaces, doc);
//Get the Triples as a Sorted List
List<Triple> ts = context.Graph.Triples.Where(t => !context.TriplesDone.Contains(t)).ToList();
ts.Sort();
//Variables we need to track our writing
INode lastSubj, lastPred;
lastSubj = lastPred = null;
XmlElement subj, pred;
//Initialise stuff to keep the compiler happy
subj = doc.CreateElement("rdf:Description", NamespaceMapper.RDF);
pred = doc.CreateElement("temp");
for (int i = 0; i < ts.Count; i++)
{
Triple t = ts[i];
if (context.TriplesDone.Contains(t)) continue; //Skip if already done
if (lastSubj == null || !t.Subject.Equals(lastSubj))
{
//Start a new set of Triples
//Validate Subject
//Use a Type Reference if applicable
if (typerefs.ContainsKey(t.Subject))
{
String tref = typerefs[t.Subject];
String tprefix;
if (tref.StartsWith(":"))
{
tprefix = String.Empty;
}
else if (tref.Contains(":"))
{
tprefix = tref.Substring(0, tref.IndexOf(':'));
}
else
{
tprefix = String.Empty;
}
subj = doc.CreateElement(tref, context.Graph.NamespaceMap.GetNamespaceUri(tprefix).ToString());
}
else
{
subj = doc.CreateElement("rdf:Description", NamespaceMapper.RDF);
}
//Write out the Subject
doc.DocumentElement.AppendChild(subj);
lastSubj = t.Subject;
//Apply appropriate attributes
switch (t.Subject.NodeType)
{
case NodeType.GraphLiteral:
throw new RdfOutputException(WriterErrorMessages.GraphLiteralsUnserializable("RDF/XML"));
case NodeType.Literal:
throw new RdfOutputException(WriterErrorMessages.LiteralSubjectsUnserializable("RDF/XML"));
case NodeType.Blank:
if (context.Collections.ContainsKey(t.Subject))
{
this.GenerateCollectionOutput(context, t.Subject, subj, ref nextNamespaceID, tempNamespaces, doc);
}
else
{
XmlAttribute nodeID = doc.CreateAttribute("rdf:nodeID", NamespaceMapper.RDF);
nodeID.Value = ((IBlankNode)t.Subject).InternalID;
subj.Attributes.Append(nodeID);
}
break;
case NodeType.Uri:
this.GenerateUriOutput(context, (IUriNode)t.Subject, "rdf:about", tempNamespaces, subj, doc);
break;
default:
throw new RdfOutputException(WriterErrorMessages.UnknownNodeTypeUnserializable("RDF/XML"));
}
//Write the Predicate
pred = this.GeneratePredicateNode(context, t.Predicate, ref nextNamespaceID, tempNamespaces, doc, subj);
subj.AppendChild(pred);
lastPred = t.Predicate;
}
else if (lastPred == null || !t.Predicate.Equals(lastPred))
{
//Write the Predicate
pred = this.GeneratePredicateNode(context, t.Predicate, ref nextNamespaceID, tempNamespaces, doc, subj);
subj.AppendChild(pred);
lastPred = t.Predicate;
}
//Write the Object
//Create an Object for the Object
switch (t.Object.NodeType)
{
case NodeType.Blank:
if (pred.HasChildNodes || pred.HasAttributes)
{
//Require a new Predicate
pred = this.GeneratePredicateNode(context, t.Predicate, ref nextNamespaceID, tempNamespaces, doc, subj);
subj.AppendChild(pred);
}
if (context.Collections.ContainsKey(t.Object))
{
//Output a Collection
this.GenerateCollectionOutput(context, t.Object, pred, ref nextNamespaceID, tempNamespaces, doc);
}
else
{
//Terminate the Blank Node triple by adding a rdf:nodeID attribute
XmlAttribute nodeID = doc.CreateAttribute("rdf:nodeID", NamespaceMapper.RDF);
nodeID.Value = ((IBlankNode)t.Object).InternalID;
pred.Attributes.Append(nodeID);
}
//Force a new Predicate after Blank Nodes
lastPred = null;
break;
case NodeType.GraphLiteral:
throw new RdfOutputException(WriterErrorMessages.GraphLiteralsUnserializable("RDF/XML"));
case NodeType.Literal:
ILiteralNode lit = (ILiteralNode)t.Object;
if (pred.HasChildNodes || pred.HasAttributes)
{
//Require a new Predicate
pred = this.GeneratePredicateNode(context, t.Predicate, ref nextNamespaceID, tempNamespaces, doc, subj);
subj.AppendChild(pred);
}
this.GenerateLiteralOutput(context, lit, pred, doc);
//Force a new Predicate Node after Literals
lastPred = null;
break;
case NodeType.Uri:
this.GenerateUriOutput(context, (IUriNode)t.Object, "rdf:resource", tempNamespaces, pred, doc);
//Force a new Predicate Node after URIs
lastPred = null;
break;
default:
throw new RdfOutputException(WriterErrorMessages.UnknownNodeTypeUnserializable("RDF/XML"));
}
context.TriplesDone.Add(t);
}
//Check we haven't failed to output any collections
foreach (KeyValuePair<INode, OutputRdfCollection> pair in context.Collections)
{
if (!pair.Value.HasBeenWritten)
{
if (typerefs.ContainsKey(pair.Key))
{
String tref = typerefs[pair.Key];
String tprefix;
if (tref.StartsWith(":"))
{
tref = tref.Substring(1);
tprefix = String.Empty;
}
else if (tref.Contains(":"))
{
tprefix = tref.Substring(0, tref.IndexOf(':'));
}
else
{
tprefix = String.Empty;
}
subj = doc.CreateElement(tref, context.Graph.NamespaceMap.GetNamespaceUri(tprefix).ToString());
doc.DocumentElement.AppendChild(subj);
this.GenerateCollectionOutput(context, pair.Key, subj, ref nextNamespaceID, tempNamespaces, doc);
}
else
{
//Generate an rdf:Description Node with a rdf:nodeID on it
XmlElement colNode = doc.CreateElement("rdf:Description");
XmlAttribute nodeID = doc.CreateAttribute("rdf:nodeID");
nodeID.Value = ((IBlankNode)pair.Key).InternalID;
colNode.Attributes.Append(nodeID);
doc.DocumentElement.AppendChild(colNode);
this.GenerateCollectionOutput(context, pair.Key, colNode, ref nextNamespaceID, tempNamespaces, doc);
//throw new RdfOutputException("Failed to output a Collection due to an unknown error");
}
}
}
//Save to the Output Stream
InternalXmlWriter writer = new InternalXmlWriter();
writer.Save(context.Output, doc);
//Get rid of the Temporary Namespace
foreach (String tempPrefix in tempNamespaces)
{
context.Graph.NamespaceMap.RemoveNamespace(tempPrefix);
}
}
