private static string WriteLiteralNode(ILiteralNode literalnode, Triple t, BaseWriterContext context, bool collapseLiterals)
{
// Example output:
// "h" [label = "v", shape = box];
// where h is the hash of the triple containing the literal node
// and v is value of literal node
// Literal nodes are identified either by their value or by their containing triple.
// When identified by value, there will be a single node representing all literals with the same value.
// When identified by triple, there will be a separate node representing each triple that has an object with that value.
var idObject = collapseLiterals ? literalnode as object : t as object;
var nodeId = idObject.GetHashCode().ToString();
GraphVizWriter.Prettify(DOT.Tab, context);
GraphVizWriter.WriteQuoted(nodeId, context);
GraphVizWriter.Prettify(DOT.Space, context);
context.Output.Write(DOT.OpenSquare);
context.Output.Write(DOT.Label);
GraphVizWriter.Prettify(DOT.Space, context);
context.Output.Write(DOT.Equal);
GraphVizWriter.Prettify(DOT.Space, context);
GraphVizWriter.WriteLiteralNodeLabel(literalnode, context);
context.Output.Write(DOT.Comma);
GraphVizWriter.Prettify(DOT.Space, context);
context.Output.Write(DOT.Shape);
GraphVizWriter.Prettify(DOT.Space, context);
context.Output.Write(DOT.Equal);
GraphVizWriter.Prettify(DOT.Space, context);
context.Output.Write(DOT.Box);
context.Output.Write(DOT.CloseSquare);
context.Output.Write(DOT.NewLine, context);
return(nodeId);
}
private static void WriteTriple(Triple triple, BaseWriterContext context, bool collapseLiterals)
{
// Output Node lines for Literal Node so we show them as Boxes
// This is in keeping with Standard Graph representation of RDF
// Literals are shown in Boxes, Uri Nodes in ellipses (GraphViz's default shape)
var subjectId = GraphVizWriter.ProcessNode(triple, TripleSegment.Subject, context, collapseLiterals);
var objectId = GraphVizWriter.ProcessNode(triple, TripleSegment.Object, context, collapseLiterals);
// Output the actual lines that state the relationship between the Nodes
// We use the Predicate as the Label on the relationship
var predicateLabel = GraphVizWriter.ReduceToQName((triple.Predicate as IUriNode).Uri, context);
GraphVizWriter.Prettify(DOT.Tab, context);
GraphVizWriter.WriteQuoted(subjectId, context);
GraphVizWriter.Prettify(DOT.Space, context);
context.Output.Write(DOT.Arrow);
GraphVizWriter.Prettify(DOT.Space, context);
GraphVizWriter.WriteQuoted(objectId, context);
GraphVizWriter.Prettify(DOT.Space, context);
context.Output.Write(DOT.OpenSquare);
context.Output.Write(DOT.Label);
GraphVizWriter.Prettify(DOT.Space, context);
context.Output.Write(DOT.Equal);
GraphVizWriter.Prettify(DOT.Space, context);
GraphVizWriter.WriteQuoted(predicateLabel, context);
context.Output.Write(DOT.CloseSquare);
context.Output.Write(DOT.Semicolon);
GraphVizWriter.Prettify(DOT.NewLine, context);
}
private static void WriteGraph(BaseWriterContext context, bool collapseLiterals)
{
context.Output.Write(DOT.Digraph);
if (context.Graph.BaseUri != null)
{
var graphId = GraphVizWriter.ReduceToQName(context.Graph.BaseUri, context);
GraphVizWriter.Prettify(DOT.Space, context);
GraphVizWriter.WriteQuoted(graphId, context);
}
GraphVizWriter.Prettify(DOT.Space, context);
context.Output.Write(DOT.OpenCurly);
GraphVizWriter.Prettify(DOT.NewLine, context);
foreach (var t in context.Graph.Triples)
{
GraphVizWriter.WriteTriple(t, context, collapseLiterals);
}
context.Output.Write(DOT.CloseCurly);
}