public IEnumerable <T> GetResources <T>(int offset = -1, int limit = -1) where T : Resource
{
if (!_query.ProvidesStatements())
{
throw new ArgumentException("Error: The given SELECT query cannot be resolved into statements.");
}
if (!_query.IsInferenceEnabled)
{
String queryString = SparqlSerializer.SerializeOffsetLimit(_model, _query, offset, limit);
SparqlQuery query = new SparqlQuery(queryString);
using (DataTable queryResults = _store.ExecuteQuery(_store.CreateQuery(query), _transaction))
{
foreach (T t in GenerateResources <T>(queryResults))
{
yield return(t);
}
}
}
else
{
// TODO: Make resources which are returned from a inferenced query read-only in order to improve query performance.
// NOTE: When inferencing is enabled, we are unable to determine which triples were inferred and
// which not. Therefore we need to issue a query to get the URIs of all the resources the original
// query would return and issue another query to describe those resources withoud inference.
List <UriRef> uris = FetchUris(offset, limit).ToList();
if (!uris.Count.Equals(0))
{
StringBuilder queryBuilder = new StringBuilder();
foreach (Uri uri in uris)
{
queryBuilder.Append(SparqlSerializer.SerializeUri(uri));
}
SparqlQuery query = new SparqlQuery(string.Format("DESCRIBE {0}", queryBuilder.ToString()));
ISparqlQueryResult queryResult = _model.ExecuteQuery(query);
if (_isOrdered)
{
foreach (T t in queryResult.GetResources <T>().OrderBy(o => uris.IndexOf(o.Uri)))
{
yield return(t);
}
}
else
{
foreach (T t in queryResult.GetResources <T>())
{
yield return(t);
}
}
}
}
}
/// <summary>
/// Retrieves a resource from the model.
/// </summary>
/// <param name="uri">A Uniform Resource Identifier.</param>
/// <param name="transaction">Transaction associated with this action.</param>
/// <returns>A resource with all asserted properties.</returns>
public IResource GetResource(Uri uri, ITransaction transaction = null)
{
ISparqlQuery query = new SparqlQuery("SELECT DISTINCT ?s ?p ?o " + DatasetClause + " WHERE { ?s ?p ?o. FILTER (?s = @subject) }");
query.Bind("@subject", uri);
ISparqlQueryResult result = ExecuteQuery(query, transaction: transaction);
IList resources = result.GetResources().ToList();
if (resources.Count > 0)
{
Resource r = resources[0] as Resource;
r.IsNew = false;
r.IsReadOnly = true;
r.IsSynchronized = true;
r.SetModel(this);
return((IResource)resources[0]);
}
else
{
throw new ResourceNotFoundException(uri);
}
}
/// <summary>
/// Retrieves a resource from the model. Provides a resource object of the given type.
/// </summary>
/// <param name="uri">A Uniform Resource Identifier.</param>
/// <param name="transaction">ransaction associated with this action.</param>
/// <returns>A resource with all asserted properties.</returns>
public T GetResource <T>(Uri uri, ITransaction transaction = null) where T : Resource
{
ISparqlQuery query = new SparqlQuery("SELECT ?s ?p ?o FROM @model WHERE { ?s ?p ?o. FILTER (?s = @subject) }");
query.Bind("@model", this.Uri);
query.Bind("@subject", uri);
ISparqlQueryResult result = ExecuteQuery(query, transaction: transaction);
IEnumerable <T> resources = result.GetResources <T>();
if (resources.Any())
{
T r = resources.First();
r.IsNew = false;
r.IsSynchronized = true;
r.SetModel(this);
return(r);
}
else
{
string msg = "Error: Could not find resource <{0}>.";
throw new ArgumentException(string.Format(msg, uri));
}
}
public IEnumerable <T> GetResources <T>(int offset = -1, int limit = -1) where T : Resource
{
_query.Offset = offset;
_query.Limit = limit;
if (_inferenceEnabled)
{
SparqlQuery uriQuery = new SparqlQuery(SparqlSerializer.Serialize(_model, _query, true));
StringBuilder uris = new StringBuilder();
var uriList = FetchUris(uriQuery).ToList();
foreach (Uri u in uriList)
{
if (u != null)
{
uris.Append(SparqlSerializer.SerializeUri(u));
}
}
if (!uriList.Any())
{
return(new List <T>());
}
SparqlQuery query = new SparqlQuery(string.Format("DESCRIBE {0} {1}", uris, SparqlSerializer.GenerateDatasetClause(_model)));
ISparqlQueryResult res = _model.ExecuteQuery(query);
if (IsSorted)
{
return(res.GetResources <T>().OrderBy(o => { return (o != null) ? uriList.IndexOf(o.Uri) : -1; }));
}
else
{
return(res.GetResources <T>());
}
}
else
{
SparqlQuery query = new SparqlQuery(SparqlSerializer.Serialize(_model, _query));
return(_model.ExecuteQuery(query, _inferenceEnabled).GetResources <T>());
}
}
public void TestSelect()
{
// Retrieving bound variables using the SELECT query form.
SparqlQuery query = new SparqlQuery("SELECT ?name ?birthday WHERE { ?x nco:fullname ?name. ?x nco:birthDate ?birthday. }");
ISparqlQueryResult result = Model.ExecuteQuery(query);
Assert.AreEqual(1, result.GetBindings().Count());
// Retrieving resoures using the SELECT or DESCRIBE query form.
query = new SparqlQuery("SELECT ?s ?p ?o WHERE { ?s ?p ?o. ?s nco:fullname 'Hans Wurscht'. }");
result = Model.ExecuteQuery(query);
Assert.AreEqual(1, result.GetResources().Count());
// Test SELECT with custom defined PREFIXes
query = new SparqlQuery("PREFIX nco: <http://www.semanticdesktop.org/ontologies/2007/03/22/nco#> SELECT ?s ?p ?o WHERE { ?s ?p ?o. ?s nco:fullname 'Hans Wurscht'. }");
result = Model.ExecuteQuery(query);
Assert.AreEqual(1, result.GetResources().Count());
// Check if the select statement only works on the given model.
query = new SparqlQuery("SELECT * WHERE { ?s ?p ?o. }");
result = Model.ExecuteQuery(query);
Assert.AreEqual(5, result.GetResources().Count());
// Check that resource creation is done correctly for Resources containing dashes.
IResource r0 = Model.CreateResource(new Uri("http://example.org/Something#0"));
r0.AddProperty(new Property(new Uri("http://example.org/fullName")), "Something");
r0.Commit();
IResource r1 = Model.CreateResource(new Uri("http://example.org/Something#1"));
r1.AddProperty(new Property(new Uri("http://example.org/fullName")), "Anotherthing");
r1.Commit();
query = new SparqlQuery("SELECT * WHERE { ?s ?p ?o. }");
result = Model.ExecuteQuery(query);
Assert.AreEqual(7, result.GetResources().Count());
}
public void TestDescribe()
{
SparqlQuery query = new SparqlQuery("DESCRIBE <http://example.org/Hans>");
ISparqlQueryResult result = Model.ExecuteQuery(query);
IList resources = result.GetResources().ToList();
Assert.AreEqual(1, resources.Count);
query = new SparqlQuery("DESCRIBE ?s WHERE { ?s nco:fullname 'Hans Wurscht'. }");
result = Model.ExecuteQuery(query);
resources = result.GetResources <PersonContact>().ToList();
Assert.AreEqual(1, resources.Count);
foreach (Contact c in resources)
{
Assert.AreEqual(c.GetType(), typeof(PersonContact));
}
}
public void TestConstruct()
{
SparqlQuery query = new SparqlQuery(@"
CONSTRUCT
{
?x vcard:N _:v .
_:v vcard:givenName ?name .
}
WHERE
{
?x nco:fullname ?name .
}");
ISparqlQueryResult result = Model.ExecuteQuery(query);
IList resources = result.GetResources().ToList();
Assert.AreEqual(2, resources.Count);
}
public void TestConstruct()
{
Assert.Inconclusive("Blank nodes are currently problematic.");
SparqlQuery query = new SparqlQuery(@"
CONSTRUCT
{
?x vcard:N _:v .
_:v vcard:givenName ?name .
}
WHERE
{
?x nco:fullname ?name .
}");
ISparqlQueryResult result = Model.ExecuteQuery(query);
IList resources = result.GetResources().ToList();
Assert.AreEqual(2, resources.Count);
}
public T GetResource <T>(Uri uri, ITransaction transaction = null) where T : Resource
{
SparqlQuery query = new SparqlQuery(String.Format("DESCRIBE {0} {1}", SparqlSerializer.SerializeUri(uri), DatasetClause));
ISparqlQueryResult result = ExecuteQuery(query, transaction: transaction);
IList resources = result.GetResources <T>().ToList();
if (resources.Count > 0)
{
T res = resources[0] as T;
res.IsNew = false;
res.IsSynchronized = true;
res.IsReadOnly = true;
res.SetModel(this);
return(res);
}
else
{
string msg = "Error: Could not find resource <{0}>.";
throw new ArgumentException(string.Format(msg, uri));
}
}
/// <summary>
/// Retrieves a resource from the model.
/// </summary>
/// <param name="uri">A Uniform Resource Identifier.</param>
/// <param name="transaction">Transaction associated with this action.</param>
/// <returns>A resource with all asserted properties.</returns>
public IResource GetResource(Uri uri, ITransaction transaction = null)
{
ISparqlQuery query = new SparqlQuery("SELECT DISTINCT ?s ?p ?o FROM @model WHERE { ?s ?p ?o. FILTER (?s = @subject) }");
query.Bind("@model", this.Uri);
query.Bind("@subject", uri);
ISparqlQueryResult result = ExecuteQuery(query, transaction: transaction);
IEnumerable <Resource> resources = result.GetResources();
foreach (Resource r in resources)
{
r.IsNew = false;
r.IsSynchronized = true;
r.SetModel(this);
return(r);
}
throw new ResourceNotFoundException(uri);
}
public void TestSetLimit()
{
SparqlQuery query = new SparqlQuery(@"
SELECT ?s0 ?p0 ?o0 WHERE
{
?s0 ?p0 ?o0 .
{
SELECT DISTINCT ?s0 WHERE
{
?s ?p ?o.
?s @type @class .
{
?s ?p1 ?o1 .
FILTER ISLITERAL(?o1) . FILTER REGEX(STR(?o1), '', 'i') .
}
UNION
{
?s ?p1 ?s1 .
?s1 ?p2 ?o2 .
FILTER ISLITERAL(?o2) . FILTER REGEX(STR(?o2), '', 'i') .
}
}
ORDER BY ?o
}
}");
query.Bind("@type", rdf.type);
query.Bind("@class", tmo.Task);
MethodInfo method = query.GetType().GetMethod("SetLimit", BindingFlags.NonPublic | BindingFlags.Instance);
method.Invoke(query, new object[] { 10 });
ISparqlQueryResult result = Model.ExecuteQuery(query);
List <Resource> resources = result.GetResources().ToList();
}
/// <summary>
/// Enumerator of the items. Should be narrowed with offset and limit.
/// </summary>
/// <param name="offset">Offset of the element where to start.</param>
/// <param name="limit">Number of elements.</param>
/// <returns></returns>
public IEnumerable <T> GetItems(int offset, int limit)
{
return(_queryResult.GetResources <T>(offset, limit));
}
