/// <summary>Visits a select clause.</summary>
/// <param name="selectClause">Select clause to be visited.</param>
/// <param name="queryModel">Query model containing given select clause.</param>
public override void VisitSelectClause(SelectClause selectClause, Remotion.Linq.QueryModel queryModel)
{
QuerySourceReferenceExpression querySource = FindQuerySource(selectClause.Selector);
_visitor.VisitExpression(selectClause.Selector);
QueryComponent component = _visitor.RetrieveComponent();
_query = _visitor.Query;
_mainFromComponent = _query.FindAllComponents<StrongEntityAccessor>().Where(item => item.SourceExpression == querySource.ReferencedQuerySource).First();
if (_query.Subject == null)
{
_query.Subject = _mainFromComponent.About;
UnboundConstrain genericConstrain = new UnboundConstrain(new Identifier("s"), new Identifier("p"), new Identifier("o"), _mainFromComponent.SourceExpression.FromExpression);
_mainFromComponent.Elements.Insert(0, genericConstrain);
_query.Select.Add(genericConstrain);
}
_subject = _query.Subject;
queryModel.MainFromClause.Accept(this, queryModel);
_query.Select.Add(_mainFromComponent);
VisitBodyClauses(queryModel.BodyClauses, queryModel);
VisitResultOperators(queryModel.ResultOperators, queryModel);
OverrideSelector(component, selectClause.Selector);
}
private void ProcessSelectableConditionalConstrainSelector(ConditionalConstrainSelector expression, bool isSubQuery, Func <string, string> createVariableName, StrongEntityAccessor mainEntityAccessor)
{
if (!isSubQuery)
{
if (mainEntityAccessor != null)
{
_currentStrongEntityAccessorVisitDelegate = entityAccessor =>
{
if (_metaGraphVariableName == null)
{
_commandText.AppendFormat("?G{0}", entityAccessor.About.Name);
}
else
{
_commandText.Append("IF(ISBLANK(");
VisitComponent(entityAccessor.About);
_commandText.Append("),");
VisitComponent(mainEntityAccessor.About);
_commandText.Append(",");
VisitComponent(entityAccessor.About);
_commandText.AppendFormat(") AS ?{0} ?{1}", _ownerVariableName, _entityVariableName);
}
};
_ownerVariableName = "entity";
}
_commandText.Append("DISTINCT ");
int index = 0;
foreach (IExpression selectable in ((ISelectableQueryComponent)expression).Expressions)
{
switch (index)
{
case 0:
_subjectVariableName = (selectable is Alias ? ((Alias)selectable).Name.Name : (selectable is Identifier ? ((Identifier)selectable).Name : null));
break;
case 1:
_predicateVariableName = (selectable is Alias ? ((Alias)selectable).Name.Name : (selectable is Identifier ? ((Identifier)selectable).Name : null));
break;
case 2:
_objectVariableName = (selectable is Alias ? ((Alias)selectable).Name.Name : (selectable is Identifier ? ((Identifier)selectable).Name : null));
break;
}
index++;
}
}
}
private void ProcessSelectableIdentifier(Identifier expression, bool isSubQuery, Func <string, string> createVariableName, StrongEntityAccessor mainEntityAccessor)
{
if (!isSubQuery)
{
if (_subjectVariableName == null)
{
_subjectVariableName = expression.Name;
}
else if (_predicateVariableName == null)
{
_predicateVariableName = expression.Name;
}
else if (_objectVariableName == null)
{
_objectVariableName = expression.Name;
}
else if ((_entityVariableName == null) || (_entityVariableName == _ownerVariableName))
{
_entityVariableName = expression.Name;
}
}
}
private void ProcessSelectableAlias(Alias expression, bool isSubQuery, Func <string, string> createVariableName, StrongEntityAccessor mainEntityAccessor)
{
if ((!isSubQuery) && (_scalarVariableName == null) && (expression.Name != null))
{
_scalarVariableName = expression.Name.Name;
}
}
private void OverrideIdentifierSelector(StrongEntityAccessor entityAccessor)
{
IdentifierEntityAccessor identifierEntityAccessor = new IdentifierEntityAccessor(entityAccessor.About, entityAccessor);
int indexOf = -1;
if ((indexOf = _query.Elements.IndexOf(entityAccessor)) != -1)
{
_query.Elements.RemoveAt(indexOf);
_query.Elements.Insert(indexOf, identifierEntityAccessor);
}
_query.Select.Clear();
_query.Select.Add(identifierEntityAccessor);
_mainFromComponent = identifierEntityAccessor;
}
/// <summary>Visit a strong entity accessor.</summary>
/// <param name="entityAccessor">Strong entity accessor to be visited.</param>
protected override void VisitStrongEntityAccessor(StrongEntityAccessor entityAccessor)
{
int startIndex = _commandText.Length;
_currentEntityAccessor.Push(entityAccessor);
_commandText.AppendFormat("GRAPH ?G{0} {{ ", entityAccessor.About.Name);
foreach (QueryElement element in entityAccessor.Elements)
{
VisitComponent(element);
}
foreach (IQueryComponent element in _injectedComponents)
{
VisitComponent(element);
if (element is Call)
{
_commandText.Append(" ");
}
}
if ((_entityAccessorToExpand != null) && (_entityAccessorToExpand.Equals(entityAccessor)))
{
int currentStartIndex = _commandText.Length;
_entityAccessorToExpand.FindAllComponents<Identifier>().Select(item => _variableNameOverride[item] = item.Name + "_sub").ToList();
_commandText.Append("{ SELECT DISTINCT ");
VisitComponent(_entityAccessorToExpand.About);
_commandText.AppendFormat(" WHERE {{ GRAPH ?G{0} {{ ", _variableNameOverride[_entityAccessorToExpand.About]);
foreach (QueryElement element in entityAccessor.Elements.SkipWhile(item => item is UnboundConstrain))
{
VisitComponent(element);
}
_commandText.AppendFormat("}} GRAPH <{0}> {{ ?G{1} <{2}> ?{1} . }} }} ", MetaGraphUri, _variableNameOverride[_entityAccessorToExpand.About], Foaf.primaryTopic);
VisitQueryResultModifiers(_entityAccessorToExpand.OwnerQuery.OrderBy, _entityAccessorToExpand.OwnerQuery.Offset, _entityAccessorToExpand.OwnerQuery.Limit);
_commandText.Append("} FILTER (");
VisitComponent(_entityAccessorToExpand.About);
_variableNameOverride.Clear();
_commandText.Append("=");
VisitComponent(_entityAccessorToExpand.About);
_commandText.Append(") ");
int currentLength = _commandText.Length - currentStartIndex;
string expansionText = _commandText.ToString().Substring(currentStartIndex, currentLength);
_commandText = _commandText.Remove(currentStartIndex, currentLength).Insert(startIndex, expansionText);
_visitedComponents.Update(startIndex, currentLength);
}
_commandText.AppendFormat("}} GRAPH <{0}> {{ ?G{1} <{2}> ?{1} . }} ", MetaGraphUri, entityAccessor.About.Name, Foaf.primaryTopic);
_currentEntityAccessor.Pop();
}
/// <summary>Default constructor with aboutness assuming that a source is a variable.</summary>
/// <param name="about">Points to the primary topic of given entity accessor.</param>
/// <param name="entityAccessor">Strong entity accessor.</param>
internal UnspecifiedEntityAccessor(Identifier about, StrongEntityAccessor entityAccessor)
: base(about)
{
_entityAccessor = entityAccessor;
}
private System.Linq.Expressions.Expression VisitPredicateMethodCallUnsafe(System.Linq.Expressions.MethodCallExpression expression, Uri predicate, StrongEntityAccessor entityAccessor)
{
_query.AddEntityAccessor(entityAccessor);
Identifier memberIdentifier = new Identifier(_query.CreateVariableName(predicate.GetFragmentOrLastSegment()));
EntityConstrain constrain = new EntityConstrain();
constrain.Predicate = new Literal(predicate);
constrain.Value = memberIdentifier;
if (!entityAccessor.Elements.Contains(constrain))
{
entityAccessor.Elements.Add(constrain);
}
if (constrain.ShouldBeOptional(_currentComponent))
{
entityAccessor.Elements.Remove(constrain);
OptionalPattern optional = new OptionalPattern();
optional.Patterns.Add(constrain);
entityAccessor.Elements.Add(optional);
}
HandleComponent(memberIdentifier);
_lastComponent = memberIdentifier;
return(expression);
}
private void ProcessSelectable(bool isSubQuery, ISelectableQueryComponent expression, Func <string, string> createVariableName, StrongEntityAccessor mainEntityAccessor)
{
System.Reflection.MethodInfo processSelectable = typeof(GenericSparqlQueryVisitor).GetTypeInfo().GetMethod("ProcessSelectable" + expression.GetType().Name, System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
if (processSelectable != null)
{
processSelectable.Invoke(this, new object[] { expression, isSubQuery, createVariableName, mainEntityAccessor });
}
foreach (IExpression selectableExpression in expression.Expressions)
{
VisitComponent(selectableExpression);
_commandText.Append(" ");
}
}
private void ExpandEntityAccessor(StrongEntityAccessor entityAccessor, ref int startIndex)
{
int currentStartIndex = _commandText.Length;
_entityAccessorToExpand.FindAllComponents <Identifier>().Select(item => _variableNameOverride[item] = item.Name + "_sub").ToList();
bool indentationChanged = false;
if (Indentation.Length > 0)
{
Indentation = Indentation.Substring(0, Indentation.Length - 1);
indentationChanged = true;
}
_commandText.Append(Indentation);
_commandText.AppendLine("{ ");
Indentation += "\t";
_commandText.Append(Indentation);
_commandText.Append("SELECT DISTINCT ");
VisitComponent(_entityAccessorToExpand.About);
_commandText.AppendLine();
_commandText.Append(Indentation);
_commandText.AppendLine("WHERE { ");
Indentation += "\t";
_commandText.Append(Indentation);
_commandText.AppendFormat("GRAPH ?G{0} {{ ", _variableNameOverride[_entityAccessorToExpand.About]);
_commandText.AppendLine();
Indentation += "\t";
foreach (QueryElement element in entityAccessor.Elements.SkipWhile(item => item is UnboundConstrain))
{
VisitComponent(element);
}
if (_entityAccessorToExpand.UnboundGraphName == null)
{
Indentation = Indentation.Substring(0, Indentation.Length - 1);
_commandText.Append(Indentation);
_commandText.AppendLine("} ");
_commandText.Append(Indentation);
_commandText.AppendFormat("GRAPH <{0}> {{ ?G{1} <{2}> ?{1} . }} ", MetaGraphUri, _variableNameOverride[_entityAccessorToExpand.About], Foaf.primaryTopic);
_commandText.AppendLine();
Indentation = Indentation.Substring(0, Indentation.Length - 1);
_commandText.Append(Indentation);
_commandText.AppendLine("} ");
}
else
{
Indentation = Indentation.Substring(0, Indentation.Length - 1);
_commandText.Append(Indentation);
_commandText.AppendLine("} ");
Indentation = Indentation.Substring(0, Indentation.Length - 1);
_commandText.Append(Indentation);
_commandText.AppendLine("} ");
}
VisitQueryResultModifiers(_entityAccessorToExpand.OwnerQuery.OrderBy, _entityAccessorToExpand.OwnerQuery.Offset, _entityAccessorToExpand.OwnerQuery.Limit);
Indentation = Indentation.Substring(0, Indentation.Length - 1);
_commandText.Append(Indentation);
_commandText.AppendLine("} ");
_commandText.Append(Indentation);
_commandText.Append("FILTER (");
VisitComponent(_entityAccessorToExpand.About);
_variableNameOverride.Clear();
_commandText.Append("=");
VisitComponent(_entityAccessorToExpand.About);
_commandText.AppendLine(") ");
int currentLength = _commandText.Length - currentStartIndex;
string expansionText = _commandText.ToString().Substring(currentStartIndex, currentLength);
_commandText = _commandText.Remove(currentStartIndex, currentLength).Insert(startIndex, expansionText);
_visitedComponents.Update(startIndex, currentLength);
if (indentationChanged)
{
Indentation += "\t";
}
}
private void VisitStrongEntityAccessorInternalQuick(StrongEntityAccessor entityAccessor)
{
VisitComponent(entityAccessor.About);
}
/// <summary>Visit a strong entity accessor.</summary>
/// <param name="entityAccessor">Strong entity accessor to be visited.</param>
protected override void VisitStrongEntityAccessor(StrongEntityAccessor entityAccessor)
{
_currentStrongEntityAccessorVisitDelegate(entityAccessor);
}
private void BeginQuery(bool isSubQuery, QueryForms queryForm, IList <ISelectableQueryComponent> select, Func <string, string> createVariableName, StrongEntityAccessor mainEntityAccessor)
{
if ((_commandText.Length > 0) && (_commandText[_commandText.Length - 1] != '\n'))
{
_commandText.AppendLine();
}
if (isSubQuery)
{
Indentation += "\t";
}
_commandText.Append(Indentation);
_commandText.AppendFormat("{0} ", queryForm.ToString().ToUpper());
if (queryForm == QueryForms.Select)
{
if (select.Count > 0)
{
Action <StrongEntityAccessor> temp = _currentStrongEntityAccessorVisitDelegate;
foreach (ISelectableQueryComponent expression in select)
{
ProcessSelectable(isSubQuery, expression, createVariableName, mainEntityAccessor);
}
_currentStrongEntityAccessorVisitDelegate = temp;
}
else
{
_commandText.Append("* ");
}
}
_commandText.AppendLine();
if (queryForm != QueryForms.Ask)
{
_commandText.Append(Indentation);
_commandText.Append("WHERE ");
}
_commandText.Append("{ ");
_commandText.AppendLine();
Indentation += "\t";
}
/// <summary>Default constructor with nagivated entity accessor.</summary>
/// <param name="entityAccessor">Nagivated entity accessor.</param>
internal StrongEntityAccessorNavigator(StrongEntityAccessor entityAccessor)
: base(entityAccessor)
{
}
private void ProcessSelectableIdentifierEntityAccessor(IdentifierEntityAccessor expression, bool isSubQuery, Func <string, string> createVariableName, StrongEntityAccessor mainEntityAccessor)
{
if (_currentStrongEntityAccessorVisitDelegate == VisitStrongEntityAccessorInternal)
{
_currentStrongEntityAccessorVisitDelegate = VisitStrongEntityAccessorInternalQuick;
}
if (!isSubQuery)
{
if ((_metaGraphVariableName == null) && (_entityVariableName == null))
{
_metaGraphVariableName = String.Format("G{0}", expression.About.Name);
_entityVariableName = _ownerVariableName = expression.About.Name + "_Distinct";
}
_subjectVariableName = expression.About.Name;
_predicateVariableName = expression.About.Name + "_Predicate";
_objectVariableName = expression.About.Name + "_Object";
_commandText.AppendFormat(
"DISTINCT(?{2}) AS ?{1} ?{0} ?{3} ?{4} ?{5} ",
_metaGraphVariableName,
_entityVariableName,
expression.About.Name,
_predicateVariableName,
_objectVariableName,
_ownerVariableName);
}
}
private System.Linq.Expressions.Expression VisitPredicateMethodCallInternal(System.Linq.Expressions.MethodCallExpression expression, Uri predicate, StrongEntityAccessor entityAccessor)
{
Type type = null;
string name = null;
if (predicate == Rdf.subject)
{
name = "Id";
type = typeof(IEntity);
}
else
{
IEntityMapping entityMapping = _entityContext.Mappings.MappingFor(expression.Arguments[0].Type);
if (entityMapping == null)
{
return(VisitPredicateMethodCallUnsafe(expression, predicate, entityAccessor));
}
IPropertyMapping propertyMapping = entityMapping.Properties.FirstOrDefault(item => item.Uri.AbsoluteUri == predicate.AbsoluteUri);
if (propertyMapping == null)
{
ExceptionHelper.ThrowMappingException(predicate);
}
if (propertyMapping.DeclaringType != expression.Arguments[0].Type)
{
propertyMapping = _entityContext.Mappings.MappingFor(propertyMapping.DeclaringType).Properties.FirstOrDefault(item => item.Uri.AbsoluteUri == predicate.AbsoluteUri);
if (propertyMapping == null)
{
ExceptionHelper.ThrowMappingException(predicate);
}
}
type = propertyMapping.EntityMapping.EntityType;
name = propertyMapping.Name;
}
System.Linq.Expressions.MemberExpression propertyExpression = System.Linq.Expressions.Expression.Property(expression.Arguments[0], type, name);
return(VisitMember(propertyExpression));
}
private void ProcessSelectableStrongEntityAccessor(StrongEntityAccessor expression, bool isSubQuery, Func <string, string> createVariableName, StrongEntityAccessor mainEntityAccessor)
{
if (_currentStrongEntityAccessorVisitDelegate == VisitStrongEntityAccessorInternal)
{
_currentStrongEntityAccessorVisitDelegate = VisitStrongEntityAccessorInternalQuick;
}
if (!isSubQuery)
{
if ((expression.UnboundGraphName != null) && (expression.UnboundGraphName != expression.About))
{
_metaGraphVariableName = (_metaGraphVariableName ?? "graph");
_entityVariableName = (_entityVariableName ?? expression.About.Name);
_ownerVariableName = (_ownerVariableName ?? expression.About.Name);
_commandText.AppendFormat("IF(BOUND(?G{0}),?G{0},?G{1}) AS ?{2} ", expression.About.Name, expression.UnboundGraphName.Name, _metaGraphVariableName);
}
else
{
_entityVariableName = (_entityVariableName ?? expression.About.Name);
_metaGraphVariableName = (_metaGraphVariableName ?? String.Format("G{0}", _entityVariableName));
_ownerVariableName = (_ownerVariableName ?? expression.About.Name);
_commandText.AppendFormat("?{0} ?{1} ", _metaGraphVariableName, _entityVariableName);
}
}
}
/// <summary>Visit a strong entity accessor.</summary> /// <param name="entityAccessor">Strong entity accessor to be visited.</param> protected abstract void VisitStrongEntityAccessor(StrongEntityAccessor entityAccessor);
private void ProcessSelectableUnboundConstrain(UnboundConstrain expression, bool isSubQuery, Func <string, string> createVariableName, StrongEntityAccessor mainEntityAccessor)
{
if ((!isSubQuery) && (expression.Subject is Identifier) && (expression.Predicate is Identifier) && (expression.Value is Identifier))
{
_subjectVariableName = ((Identifier)expression.Subject).Name;
_predicateVariableName = ((Identifier)expression.Predicate).Name;
_objectVariableName = ((Identifier)expression.Value).Name;
}
}
/// <summary>Default constructor with aboutness and its source passed.</summary>
/// <param name="about">Specifies an entity identifier given accesor uses.</param>
/// <param name="sourceExpression">Source of this entity accessor.</param>
/// <param name="entityAccessor">Strong entity accessor.</param>
internal UnspecifiedEntityAccessor(Identifier about, Remotion.Linq.Clauses.FromClauseBase sourceExpression, StrongEntityAccessor entityAccessor)
: base(about, sourceExpression)
{
_entityAccessor = entityAccessor;
}
private void ProcessSelectableCall(Call expression, bool isSubQuery, Func <string, string> createVariableName, StrongEntityAccessor mainEntityAccessor)
{
if ((!isSubQuery) && (_scalarVariableName == null))
{
_scalarVariableName = createVariableName(expression.Member.ToString());
}
}
/// <summary>Visit a query.</summary>
/// <param name="query">Query to be visited.</param>
public override void VisitQuery(Query query)
{
InitQuery(query.IsSubQuery ? null : query.Prefixes);
BeginQuery(query.IsSubQuery, query.QueryForm, query.Select, query.CreateVariableName);
_entityAccessorToExpand = ((query.Limit >= 0) || (query.Offset >= 0) || (query.OrderBy.Count > 0) ? (StrongEntityAccessor)query.Elements.LastOrDefault(item => item is StrongEntityAccessor) : null);
foreach (QueryElement element in query.Elements)
{
VisitComponent(element);
}
EndQuery(query.IsSubQuery, (_entityAccessorToExpand != null ? query.OrderBy : null));
}
private void OverrideLiteralSelector(StrongEntityAccessor entityAccessor)
{
if (_mainFromComponent.Elements[0] is UnboundConstrain)
{
entityAccessor.Elements.Add(new Filter(new BinaryOperator(MethodNames.Equal, ((UnboundConstrain)_mainFromComponent.Elements[0]).Predicate, new Literal(_propertyMapping.Uri))));
}
}
