bool Select(Entity[] subjects, Entity[] predicates, Resource[] objects, Entity[] metas, LiteralFilter[] litFilters, int limit, StatementSink sink, bool ask) {
// TODO: Change meta into named graphs. Anything but a null or DefaultMeta
// meta returns no statements immediately.
if (metas != null && (metas.Length != 1 || metas[0] != Statement.DefaultMeta))
return false;
string query;
bool nonull = false;
if (subjects != null && subjects.Length == 1
&& predicates != null && predicates.Length == 1
&& objects != null && objects.Length == 1) {
query = "ASK WHERE { " + S(subjects[0], null) + " " + S(predicates[0], null) + " " + S(objects[0], null) + "}";
nonull = true;
} else {
if (ask)
query = "ASK { ";
else
query = "SELECT * WHERE { ";
query += S(subjects, "?subject");
query += " ";
query += S(predicates, "?predicate");
query += " ";
query += S(objects, "?object");
query += " . ";
query += SL(subjects, "?subject", false);
query += SL(predicates, "?predicate", false);
query += SL(objects, "?object", false);
query += " }";
// TODO: Pass literal filters to server.
}
if (limit >= 1)
query += " LIMIT " + limit;
Statement d = new Statement(
(subjects != null && subjects.Length == 1) ? subjects[0] : null,
(predicates != null && predicates.Length == 1) ? predicates[0] : null,
(objects != null && objects.Length == 1) ? objects[0] : null);
if (ask || nonull) {
BooleanWrap bw = new BooleanWrap();
Load(query, bw);
if (ask)
return bw.value;
else if (bw.value)
sink.Add(new Statement(subjects[0], predicates[0], objects[0]));
return false;
} else {
Load(query, new QueryToStatements(sink, litFilters, d));
return true;
}
}
public void Select(SelectFilter filter, StatementSink result)
{
ResSet
s = filter.Subjects == null ? null : new ResSet(filter.Subjects),
p = filter.Predicates == null ? null : new ResSet(filter.Predicates),
o = filter.Objects == null ? null : new ResSet(filter.Objects),
m = filter.Metas == null ? null : new ResSet(filter.Metas);
foreach (Statement st in statements)
{
if (s != null && !s.Contains(st.Subject))
{
continue;
}
if (p != null && !p.Contains(st.Predicate))
{
continue;
}
if (o != null && !o.Contains(st.Object))
{
continue;
}
if (m != null && !m.Contains(st.Meta))
{
continue;
}
if (filter.LiteralFilters != null && !LiteralFilter.MatchesFilters(st.Object, filter.LiteralFilters, this))
{
continue;
}
if (!result.Add(st))
{
return;
}
}
}
private static bool MatchesFilters(Literal literal, LiteralFilter[] filters, SelectableSource targetModel) {
foreach (LiteralFilter filter in filters)
if (!filter.Filter(literal, targetModel))
return false;
return true;
}
public static bool MatchesFilters(Resource literal, LiteralFilter[] filters, SelectableSource targetModel) {
if (literal is Literal)
return MatchesFilters((Literal)literal, filters, targetModel);
return false;
}
public QueryToStatements(StatementSink sink, LiteralFilter[] litFilters, Statement d) {
this.sink = sink;
this.litFilters = litFilters;
this.d = d;
}
public void AddValueFilter(Entity entity, LiteralFilter filter) {
SetupValueFilter d = new SetupValueFilter();
d.a = entity;
d.b = filter;
setupValueFilters.Add(d);
}