/// <summary>
/// Enlists the narrower/narrowerTransitive concepts of the given concept within the given scheme
/// </summary>
public static RDFSKOSConceptScheme GetNarrowerConceptsOf(this RDFSKOSConceptScheme conceptScheme,
RDFSKOSConcept concept)
{
var result = new RDFSKOSConceptScheme((RDFResource)conceptScheme.Value);
if (concept != null && conceptScheme != null)
{
//Get skos:narrower concepts
foreach (var narrowerConcept in conceptScheme.Relations.Narrower.SelectEntriesBySubject(concept))
{
result.AddConcept((RDFSKOSConcept)narrowerConcept.TaxonomyObject);
}
//Get skos:narrowerTransitive concepts
result = result.UnionWith(conceptScheme.GetNarrowerConceptsOfInternal(concept, null))
.RemoveConcept(concept); //Safety deletion
}
return(result);
}
/// <summary>
/// Subsumes the "skos:narrowerTransitive" taxonomy to discover direct and indirect narrower concepts of the given scheme
/// </summary>
internal static RDFSKOSConceptScheme GetNarrowerConceptsOfInternal(this RDFSKOSConceptScheme conceptScheme,
RDFSKOSConcept concept,
Dictionary <long, RDFSKOSConcept> visitContext)
{
var result = new RDFSKOSConceptScheme((RDFResource)conceptScheme.Value);
#region visitContext
if (visitContext == null)
{
visitContext = new Dictionary <long, RDFSKOSConcept>()
{
{ concept.PatternMemberID, concept }
};
}
else
{
if (!visitContext.ContainsKey(concept.PatternMemberID))
{
visitContext.Add(concept.PatternMemberID, concept);
}
else
{
return(result);
}
}
#endregion
//Transitivity of "skos:narrowerTransitive" taxonomy:
//((A SKOS:NARROWERTRANSITIVE B) && (B SKOS:NARROWERTRANSITIVE C)) => (A SKOS:NARROWERTRANSITIVE C)
foreach (var nt in conceptScheme.Relations.NarrowerTransitive.SelectEntriesBySubject(concept))
{
result.AddConcept((RDFSKOSConcept)nt.TaxonomyObject);
//Exploit skos:narrowerTransitive taxonomy
result = result.UnionWith(conceptScheme.GetNarrowerConceptsOfInternal((RDFSKOSConcept)nt.TaxonomyObject, visitContext));
}
return(result);
}