public void WriteInFilter(Expression itemExpression, Expression fromExpression)
{
_filterExpressionBuilder.Append("(");
var expr = VisitExpression(itemExpression);
if (expr is SelectVariableNameExpression &&
((expr) as SelectVariableNameExpression).BindingType == VariableBindingType.Resource)
{
_castAsResourceType = true;
_identifierPrefix = EntityMappingStore.GetIdentifierPrefix(expr.Type);
//_identifierPrefix = EntityMappingStore.GetIdentifierPrefix(((SelectVariableNameExpression)expr).
}
_filterExpressionBuilder.Append(" IN (");
VisitExpression(fromExpression);
_filterExpressionBuilder.Append("))");
_castAsResourceType = false;
}
/// <summary>
/// Convert a "Compare" expression into a SPARQL greater than / less than
/// </summary>
/// <param name="compareExpression"></param>
/// <param name="nodeType"></param>
/// <remarks>The Compare expression is used by Microsoft WCF Data Services when a OData call is made with a $skiptoken query option. This token is used to find the starting point in a collection of entities</remarks>
private void HandleCompareExpression(MethodCallExpression compareExpression, ExpressionType nodeType)
{
var filter = nodeType == ExpressionType.GreaterThan
? "(?{0} > '{1}')"
: "(?{0} < '{1}')";
var expression = compareExpression.Arguments[0] as MemberExpression;
var sourceVarName = GetSourceVarName(expression);
var constantExpression = compareExpression.Arguments[1] as ConstantExpression;
var value = constantExpression.Value.ToString();
if (sourceVarName != null)
{
#if PORTABLE
if (expression.Member is PropertyInfo)
#else
if (expression.Member.MemberType == MemberTypes.Property)
#endif
{
var propertyInfo = expression.Member as PropertyInfo;
var hint = QueryBuilder.Context.GetPropertyHint(propertyInfo);
if (hint != null)
{
switch (hint.MappingType)
{
case PropertyMappingType.Id:
filter = nodeType == ExpressionType.GreaterThan
? "(str(?{0}) > '{1}')"
: "(str(?{0}) < '{1}')";
var prefix = EntityMappingStore.GetIdentifierPrefix(propertyInfo.DeclaringType);
_filterWriter.AppendFormat(filter, sourceVarName, prefix + value);
break;
case PropertyMappingType.Arc:
case PropertyMappingType.Property:
{
var existingVarName = QueryBuilder.GetVariableForObject(GraphNode.Variable,
sourceVarName,
GraphNode.Iri,
hint.SchemaTypeUri);
if (!String.IsNullOrEmpty(existingVarName))
{
_filterWriter.AppendFormat(filter, existingVarName, value);
}
else
{
var varName = QueryBuilder.NextVariable();
QueryBuilder.AddTripleConstraint(
GraphNode.Variable, sourceVarName,
GraphNode.Iri, hint.SchemaTypeUri,
GraphNode.Variable, varName);
_filterWriter.AppendFormat(filter, varName, value);
}
break;
}
case PropertyMappingType.InverseArc:
{
var existingVarName = QueryBuilder.GetVariableForSubject(GraphNode.Iri,
hint.SchemaTypeUri,
GraphNode.Variable,
sourceVarName);
if (!String.IsNullOrEmpty(existingVarName))
{
_filterWriter.AppendFormat(filter, existingVarName, value);
}
else
{
var varName = QueryBuilder.NextVariable();
QueryBuilder.AddTripleConstraint(GraphNode.Variable, varName,
GraphNode.Iri, hint.SchemaTypeUri,
GraphNode.Variable, sourceVarName);
_filterWriter.AppendFormat(filter, varName, value);
}
}
break;
case PropertyMappingType.Address:
_filterWriter.AppendFormat(filter, sourceVarName, value);
break;
}
}
}
}
}
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));
}