protected string GetSourceVarName(MemberExpression expression)
{
string sourceVarName = null;
if (expression.Expression is QuerySourceReferenceExpression)
{
var querySource = expression.Expression as QuerySourceReferenceExpression;
Expression mappedExpression;
if (QueryBuilder.TryGetQuerySourceMapping(querySource.ReferencedQuerySource, out mappedExpression) &&
mappedExpression is SelectVariableNameExpression)
{
sourceVarName = (mappedExpression as SelectVariableNameExpression).Name;
}
else
{
sourceVarName = querySource.ReferencedQuerySource.ItemName;
QueryBuilder.AddQuerySourceMapping(
querySource.ReferencedQuerySource,
new SelectVariableNameExpression(querySource.ReferencedQuerySource.ItemName, VariableBindingType.Resource, querySource.ReferencedQuerySource.ItemType));
}
}
else if (expression.Expression is MemberExpression)
{
var memberExpression = VisitExpression(expression.Expression);
if (memberExpression is SelectVariableNameExpression)
{
sourceVarName = (memberExpression as SelectVariableNameExpression).Name;
}
}
return(sourceVarName);
}
private string GetExpressionVariable(Expression expression)
{
if (expression is QuerySourceReferenceExpression)
{
var querySource = expression as QuerySourceReferenceExpression;
Expression mappedExpression;
_queryBuilder.TryGetQuerySourceMapping(querySource.ReferencedQuerySource, out mappedExpression);
if (mappedExpression is SelectVariableNameExpression)
return (mappedExpression as SelectVariableNameExpression).Name;
}
var selector = SparqlGeneratorWhereExpressionTreeVisitor.GetSparqlExpression(expression, _queryBuilder);
if (selector is SelectVariableNameExpression) return (selector as SelectVariableNameExpression).Name;
return null;
}
private string GetExpressionVariable(Expression expression)
{
if (expression is QuerySourceReferenceExpression)
{
var querySource = expression as QuerySourceReferenceExpression;
Expression mappedExpression;
_queryBuilder.TryGetQuerySourceMapping(querySource.ReferencedQuerySource, out mappedExpression);
if (mappedExpression is SelectVariableNameExpression)
{
return((mappedExpression as SelectVariableNameExpression).Name);
}
}
var selector = SparqlGeneratorWhereExpressionTreeVisitor.GetSparqlExpression(expression, _queryBuilder, _context.FilterOptimizationEnabled);
if (selector is SelectVariableNameExpression)
{
return((selector as SelectVariableNameExpression).Name);
}
return(null);
}
protected override Expression VisitMemberExpression(MemberExpression expression)
{
string sourceVarName = null;
if (expression.Expression is QuerySourceReferenceExpression)
{
var source = expression.Expression as QuerySourceReferenceExpression;
Expression mappedSourceExpression;
sourceVarName = source.ReferencedQuerySource.ItemName;
if (_queryBuilder.TryGetQuerySourceMapping(source.ReferencedQuerySource, out mappedSourceExpression) && mappedSourceExpression is SelectVariableNameExpression)
{
sourceVarName = (mappedSourceExpression as SelectVariableNameExpression).Name;
}
}
else if (expression.Expression is MemberExpression)
{
var memberExpression = VisitExpression(expression.Expression);
if (memberExpression is SelectVariableNameExpression)
{
sourceVarName = (memberExpression as SelectVariableNameExpression).Name;
}
}
else if (expression.Expression is UnaryExpression)
{
var unary = expression.Expression as UnaryExpression;
if (unary.NodeType == ExpressionType.TypeAs &&
unary.Operand is QuerySourceReferenceExpression)
{
var targetType = unary.Type;
var source = unary.Operand as QuerySourceReferenceExpression;
if (source != null)
{
var itemType = source.ReferencedQuerySource.ItemType;
if (targetType.IsAssignableFrom(itemType))
{
expression = Expression.MakeMemberAccess(unary.Operand, expression.Member);
return(VisitExpression(expression));
}
}
}
var updatedExpression = VisitExpression(expression.Expression) as UnaryExpression;
if (updatedExpression != null && updatedExpression.Operand is SelectVariableNameExpression)
{
#if WINDOWS_PHONE || PORTABLE
return(Expression.MakeMemberAccess(updatedExpression, expression.Member));
#else
return(expression.Update(updatedExpression));
#endif
}
}
if (!String.IsNullOrEmpty(sourceVarName))
{
#if PORTABLE
if (expression.Member is PropertyInfo)
#else
if (expression.Member.MemberType == MemberTypes.Property)
#endif
{
var propertyInfo = expression.Member as PropertyInfo;
var propertyHint = _queryBuilder.Context.GetPropertyHint(propertyInfo);
if (propertyHint != null)
{
switch (propertyHint.MappingType)
{
case PropertyMappingType.Arc:
{
var memberVarName = _queryBuilder.GetVariableForObject(
GraphNode.Variable, sourceVarName,
GraphNode.Iri, propertyHint.SchemaTypeUri);
if (memberVarName == null)
{
memberVarName = _queryBuilder.NextVariable();
_queryBuilder.AddTripleConstraint(
GraphNode.Variable, sourceVarName,
GraphNode.Iri, propertyHint.SchemaTypeUri,
GraphNode.Variable, memberVarName);
}
return(new SelectVariableNameExpression(memberVarName, VariableBindingType.Resource, propertyInfo.PropertyType));
}
case PropertyMappingType.InverseArc:
{
var memberVarName = _queryBuilder.GetVariableForSubject(
GraphNode.Iri, propertyHint.SchemaTypeUri,
GraphNode.Variable, sourceVarName);
if (memberVarName == null)
{
memberVarName = _queryBuilder.NextVariable();
_queryBuilder.AddTripleConstraint(
GraphNode.Variable, memberVarName,
GraphNode.Iri, propertyHint.SchemaTypeUri,
GraphNode.Variable, sourceVarName);
}
return(new SelectVariableNameExpression(memberVarName, VariableBindingType.Resource, propertyInfo.PropertyType));
}
case PropertyMappingType.Property:
{
var propertyValueVarName = _queryBuilder.GetVariableForObject(GraphNode.Variable,
sourceVarName,
GraphNode.Iri,
propertyHint.
SchemaTypeUri);
if (propertyValueVarName == null)
{
propertyValueVarName = _queryBuilder.NextVariable();
_queryBuilder.AddTripleConstraint(
GraphNode.Variable, sourceVarName,
GraphNode.Iri, propertyHint.SchemaTypeUri,
GraphNode.Variable, propertyValueVarName);
}
return(new SelectVariableNameExpression(propertyValueVarName,
VariableBindingType.Literal, propertyInfo.PropertyType));
}
case PropertyMappingType.Address:
{
return(new SelectVariableNameExpression(sourceVarName, VariableBindingType.Resource, propertyInfo.PropertyType));
}
case PropertyMappingType.Id:
{
var prefix = EntityMappingStore.GetIdentifierPrefix(propertyInfo.DeclaringType);
return(new SelectIdentifierVariableNameExpression(sourceVarName, prefix));
//return new SelectVariableNameExpression(sourceVarName, VariableBindingType.Resource, propertyInfo.PropertyType);
}
}
}
}
}
return(base.VisitMemberExpression(expression));
}
