public IEnumerable <T> GetResources <T>(ResourceQuery query, bool inferenceEnabled = false, ITransaction transaction = null) where T : Resource
{
IEnumerable <T> result = ExecuteQuery(query, inferenceEnabled, transaction).GetResources <T>();
// TODO: Could be done in the SparqlQueryResult for increased performance.
if (result != null)
{
foreach (object r in result)
{
T t = r as T;
// NOTE: This safeguard is required because of a bug in ExecuteQuery where
// it returns null objects when a rdf:type triple is missing..
if (t == null)
{
continue;
}
t.SetModel(this);
t.IsNew = false;
t.IsSynchronized = true;
t.IsReadOnly = true;
yield return(t);
}
}
}
public ResourceQueryResult(IModel model, ResourceQuery query, bool inferenceEnabled, ITransaction transaction)
{
_model = model;
_query = query;
_inferenceEnabled = inferenceEnabled;
_transaction = transaction;
}
/// <summary>
/// Returns a enumeration of all resources that match the given type.
/// </summary>
/// <param name="inferenceEnabled">Indicate that this query should work with enabled inferencing.</param>
/// <param name="transaction">transaction associated with this action.</param>
/// <returns>An enumeration of resources that match the given query.</returns>
public IEnumerable <T> GetResources <T>(bool inferenceEnabled = false, ITransaction transaction = null) where T : Resource
{
T temp = (T)Activator.CreateInstance(typeof(T), new Uri("semio:desk"));
ResourceQuery query = new ResourceQuery(temp.GetTypes());
query.InferencingEnabled = inferenceEnabled;
return(GetResources <T>(query, inferenceEnabled, transaction));
}
/// <summary>
/// Serialize a ResourceQuery from certain model. Can also only deliver the Uris of the result resources.
/// </summary>
/// <param name="model"></param>
/// <param name="query"></param>
/// <param name="onlyUris"></param>
/// <returns></returns>
public static string Serialize(IModel model, ResourceQuery query, bool onlyUris = false)
{
StringBuilder result = new StringBuilder();
StringBuilder whereBlock = new StringBuilder();
StringBuilder modifierBlock = new StringBuilder();
SortedList <int, string> orderModifiers = new SortedList <int, string>();
Serialize(model, query, whereBlock, orderModifiers, new List <ResourceQuery>());
if (orderModifiers.Count > 0)
{
modifierBlock.Append("ORDER BY ");
foreach (string value in orderModifiers.Values)
{
modifierBlock.Append(value);
}
}
if (query.Offset != -1)
{
modifierBlock.Append(" OFFSET ");
modifierBlock.Append(query.Offset);
}
if (query.Limit != -1)
{
modifierBlock.Append(" LIMIT ");
modifierBlock.Append(query.Limit);
}
if (onlyUris)
{
string q = "SELECT ?s0 {0} WHERE {{ ?s0 ?p0 ?o0 . {{ SELECT DISTINCT ?s0 WHERE {{{1}}} {2} }}}}";
result.Append(string.Format(q, GenerateDatasetClause(model), whereBlock.ToString(), modifierBlock.ToString()));
}
else
{
if (whereBlock.Length > 0)
{
// Because of a bug in OpenLink Virtuoso where it ignores ORDER BY expressions in
// DESCRIBE queries we have to emulate the describe query by a nested SELECT query.
string q = "SELECT ?s0 ?p0 ?o0 {0} WHERE {{ ?s0 ?p0 ?o0 . {{ SELECT DISTINCT ?s0 WHERE {{{1}}} {2} }}}}";
result.Append(string.Format(q, GenerateDatasetClause(model), whereBlock.ToString(), modifierBlock.ToString()));
}
else
{
string q = "DESCRIBE ?s0 {0} WHERE {{ ?s0 ?p0 ?o0 . }} {1}";
result.Append(string.Format(q, GenerateDatasetClause(model), modifierBlock.ToString()));
}
}
return(result.ToString());
}
/// <summary>
/// Executes a resource query and provides an enumeration of matching resources.
/// </summary>
/// <param name="query">A ResourceQuery object containing the query that should be executed.</param>
/// <param name="inferenceEnabled">Indicate that this query should work with enabled inferencing.</param>
/// <param name="transaction">transaction associated with this action.</param>
/// <returns>An enumeration of resources that match the given query.</returns>
public IEnumerable <Resource> GetResources(ResourceQuery query, bool inferenceEnabled = false, ITransaction transaction = null)
{
IEnumerable <Resource> result = ExecuteQuery(query, inferenceEnabled, transaction).GetResources <Resource>();
if (result != null)
{
// TODO: Should be done in the SparqlQueryResult for increased performance.
foreach (Resource r in result)
{
r.SetModel(this);
r.IsNew = false;
r.IsSynchronized = true;
}
}
return(result);
}
private bool Clone(out ResourceQuery result, IList <ResourceQuery> processed, IList <ResourceQuery> generated)
{
if (!processed.Contains(this))
{
result = new ResourceQuery();
result.Offset = Offset;
result.Limit = Limit;
processed.Add(this);
generated.Add(result);
foreach (ResourceQuery query in DependentQueries)
{
ResourceQuery q;
if (query.Clone(out q, processed, generated))
{
q.DependentQueries.Add(result);
result.DependentQueries.Add(q);
}
}
foreach (StatementPattern pattern in WhereStatements)
{
if (pattern.Object is ResourceQuery && processed.Contains(pattern.Object as ResourceQuery))
{
result.WhereStatements.Add(new StatementPattern(pattern.Subject, pattern.Predicate, generated[processed.IndexOf(pattern.Object as ResourceQuery)]));
}
else
{
result.WhereStatements.Add(pattern);
}
}
return(true);
}
else
{
result = null;
return(false);
}
}
/// <summary>
/// Serialize a count query for the given ResourceQuery
/// </summary>
/// <param name="model"></param>
/// <param name="query"></param>
/// <returns></returns>
public static string SerializeCount(IModel model, ResourceQuery query)
{
StringBuilder result = new StringBuilder();
StringBuilder where = new StringBuilder();
Serialize(model, query, where, new SortedList <int, string>(), new List <ResourceQuery>());
if (query.Uri == null)
{
result.Append(string.Format("SELECT (COUNT(DISTINCT ?s0) AS ?count) {0} WHERE {{{1}}}", GenerateDatasetClause(model), where.ToString()));
}
else
{
result.Append(string.Format("SELECT (COUNT(DISTINCT <{2}>) AS ?count) {0} WHERE {{{1}}}", GenerateDatasetClause(model), where.ToString(), query.Uri));
}
return(result.ToString());
}
public StatementPattern Where(Property property, object value = null)
{
if (value is ResourceQuery)
{
ResourceQuery query = value as ResourceQuery;
query.DependentQueries.Add(this);
this.DependentQueries.Add(query);
}
StatementPattern pattern;
if (property != null)
{
if (value != null)
{
pattern = new StatementPattern(this.Uri, property.Uri, value);
}
else
{
pattern = new StatementPattern(this.Uri, property.Uri, null);
}
}
else
{
if (value != null)
{
pattern = new StatementPattern(this.Uri, null, value);
}
else
{
throw new ArgumentException(string.Format("Error: Invalid arguments {0} {1}.", property, value));
}
}
WhereStatements.Add(pattern);
return(pattern);
}
public IResourceQueryResult ExecuteQuery(ResourceQuery query, bool inferenceEnabled = false, ITransaction transaction = null)
{
return(new ResourceQueryResult(this, query, inferenceEnabled, transaction));
}
/// <summary>
/// Serialize a query from the given parameters
/// </summary>
/// <param name="model"></param>
/// <param name="query"></param>
/// <param name="whereBlock"></param>
/// <param name="solutionModifiers"></param>
/// <param name="processed"></param>
public static void Serialize(IModel model, ResourceQuery query, StringBuilder whereBlock, SortedList <int, string> solutionModifiers, IList <ResourceQuery> processed)
{
// The index of the currently processed resource query used for generating variable names.
int i = processed.Count;
// Prevent endless loops for cyclic references.
processed.Add(query);
// Recursively serialize all the queries which reference to this query.
foreach (ResourceQuery dependentQuery in query.DependentQueries)
{
if (!processed.Contains(dependentQuery))
{
Serialize(model, dependentQuery, whereBlock, solutionModifiers, processed);
whereBlock.Append(" ");
}
}
if (query.WhereStatements.Count > 0)
{
// Counts the variables used for this resource.
string s = "?s" + i;
string p = "?p" + i;
string o = "?o" + i;
int pCount = 0;
int oCount = 0;
// We iterate over the asserted properties and generate SPARQL statements.
foreach (StatementPattern pattern in query.WhereStatements)
{
if (pattern.Object is ResourceQuery && !processed.Contains(pattern.Object as ResourceQuery))
{
continue;
}
if (pattern.Subject == null)
{
pattern.SubjectName = s;
whereBlock.Append(pattern.SubjectName + " ");
}
else
{
whereBlock.Append(SerializeUri(pattern.Subject) + " ");
}
// PREDICATE
if (pattern.Predicate is Uri)
{
// If there is a property we write the absolute URI..
whereBlock.Append(SerializeUri(pattern.Predicate) + " ");
}
else
{
pattern.PredicateName = p + pCount++;
whereBlock.Append(pattern.PredicateName + " ");
}
// OBJECT
if (pattern.Object is ResourceQuery)
{
ResourceQuery q = pattern.Object as ResourceQuery;
if (q.Uri != null)
{
// If the value is a reference to another query we write its variable name and close the statement.
whereBlock.Append(SerializeUri(q.Uri) + " . ");
}
else
{
// If the value is a reference to another query we write its variable name and close the statement.
whereBlock.Append("?s" + processed.IndexOf(q) + " . ");
}
}
else if (pattern.FilterOperation != FilterOperation.None)
{
pattern.ObjectName = o + oCount++;
switch (pattern.FilterOperation)
{
case FilterOperation.None:
break;
case FilterOperation.Equal:
whereBlock.Append(string.Format("{0} . FILTER({0} == {1}) . ", pattern.ObjectName, SerializeValue(pattern.Object)));
break;
case FilterOperation.NotEqual:
whereBlock.Append(string.Format("{0} . FILTER({0} != {1}) . ", pattern.ObjectName, SerializeValue(pattern.Object)));
break;
case FilterOperation.LessThan:
whereBlock.Append(string.Format("{0} . FILTER({0} < {1}) . ", pattern.ObjectName, SerializeValue(pattern.Object)));
break;
case FilterOperation.LessOrEqual:
whereBlock.Append(string.Format("{0} . FILTER({0} <= {1}) . ", pattern.ObjectName, SerializeValue(pattern.Object)));
break;
case FilterOperation.GreaterThan:
whereBlock.Append(string.Format("{0} . FILTER({0} > {1}) . ", pattern.ObjectName, SerializeValue(pattern.Object)));
break;
case FilterOperation.GreaterOrEqual:
whereBlock.Append(string.Format("{0} . FILTER({0} >= {1}) . ", pattern.ObjectName, SerializeValue(pattern.Object)));
break;
case FilterOperation.Contains:
whereBlock.Append(string.Format("{0} . FILTER ISLITERAL({0}) . FILTER REGEX(STR({0}), \"{1}\", \"i\") . ", pattern.ObjectName, pattern.Object));
break;
}
}
else if (pattern.Object != null)
{
// If a literal value was specified we append it and close the statement.
whereBlock.Append(SerializeValue(pattern.Object) + " . ");
}
else
{
// Save the current variable for later processing the sort descriptions..
pattern.ObjectName = o + oCount++;
// If the value is null we append a variable to the statement.
whereBlock.Append(pattern.ObjectName + " . ");
}
if (!string.IsNullOrEmpty(pattern.ObjectName))
{
if (pattern.SortDirection == SortDirection.Ascending)
{
solutionModifiers.Add(pattern.SortPriority, " ASC(" + pattern.ObjectName + ")");
}
else if (pattern.SortDirection == SortDirection.Descending)
{
solutionModifiers.Add(pattern.SortPriority, " DESC(" + pattern.ObjectName + ")");
}
}
}
}
else if (query.Uri != null)
{
whereBlock.Append(SerializeUri(query.Uri) + " ?p" + i + " ?o" + i + " . ");
}
else
{
whereBlock.Append("?s" + i + " ?p" + i + " ?o" + i + " . ");
}
}
public ResourceProvider(string name, ResourceQuery query)
{
}
public ResourceQueryItemsProvider(IModel model, ResourceQuery query, bool inferenceEnabled = true)
{
_queryResult = model.ExecuteQuery(query, inferenceEnabled);
}
/// <summary>
/// Initializes a new instance of the <see cref="VirtualizingResourceCollection{T}"/> class.
/// </summary>
public VirtualizingResourceCollection(IModel model, ResourceQuery query, bool inferenceEnabled = false)
: base(new ResourceQueryItemsProvider <T>(model, query, inferenceEnabled))
{
}
/// <summary>
/// Initializes a new instance of the <see cref="VirtualizingResourceCollection{T}"/> class.
/// </summary>
public VirtualizingResourceCollection(IModel model, ResourceQuery query, int pageSize, bool inferenceEnabled = true)
: base(new ResourceQueryItemsProvider <T>(model, query, inferenceEnabled), pageSize)
{
}