private Expression GetInnerSource(OeSelectItem navigationItem, ExpandedNavigationSelectItem item)
{
Type clrEntityType = _visitor.EdmModel.GetClrType(navigationItem.EdmProperty.DeclaringType);
PropertyInfo navigationClrProperty = OeEdmClrHelper.GetPropertyIgnoreCase(clrEntityType, navigationItem.EdmProperty);
Type itemType = OeExpressionHelper.GetCollectionItemType(navigationClrProperty.PropertyType);
if (itemType == null)
{
itemType = navigationClrProperty.PropertyType;
}
var visitor = new OeQueryNodeVisitor(_visitor, Expression.Parameter(itemType));
var expressionBuilder = new OeExpressionBuilder(_joinBuilder, visitor);
Expression innerSource = Expression.Constant(null, typeof(IEnumerable <>).MakeGenericType(itemType));
innerSource = expressionBuilder.ApplyFilter(innerSource, item.FilterOption);
if (item.SkipOption != null || item.TopOption != null)
{
Expression source = Expression.Constant(null, typeof(IEnumerable <>).MakeGenericType(navigationClrProperty.DeclaringType));
innerSource = OeCrossApplyBuilder.Build(source, innerSource, item, navigationItem.Path, expressionBuilder);
}
return(innerSource);
}
private MethodCallExpression CreateSelectExpression(Expression source, OeJoinBuilder joinBuilder)
{
if (_navigationItem.HasNavigationItems)
{
return((MethodCallExpression)source);
}
if (_navigationItem.SelectItems.Count == 0)
{
return((MethodCallExpression)source);
}
var expressions = new List <Expression>(_navigationItem.SelectItems.Count);
for (int i = 0; i < _navigationItem.SelectItems.Count; i++)
{
IEdmProperty edmProperty = _navigationItem.SelectItems[i].EdmProperty;
PropertyInfo clrProperty = OeEdmClrHelper.GetPropertyIgnoreCase(_visitor.Parameter.Type, edmProperty);
expressions.Add(Expression.MakeMemberAccess(_visitor.Parameter, clrProperty));
}
NewExpression newTupleExpression = OeExpressionHelper.CreateTupleExpression(expressions);
LambdaExpression lambda = Expression.Lambda(newTupleExpression, _visitor.Parameter);
MethodInfo selectMethodInfo = OeMethodInfoHelper.GetSelectMethodInfo(_visitor.Parameter.Type, newTupleExpression.Type);
return(Expression.Call(selectMethodInfo, source, lambda));
}
private Expression GetPropertyExpression(SingleValuePropertyAccessNode nodeIn)
{
Expression e = TranslateNode(nodeIn.Source);
PropertyInfo property = OeEdmClrHelper.GetPropertyIgnoreCase(e.Type, nodeIn.Property);
if (property == null)
{
if (!OeExpressionHelper.IsTupleType(e.Type))
{
throw new InvalidOperationException("must by Tuple " + e.Type.ToString());
}
IEdmNavigationSource navigationSource = ((ResourceRangeVariableReferenceNode)nodeIn.Source).NavigationSource;
property = GetTuplePropertyByEntityType(e.Type, navigationSource.EntityType());
}
return(Expression.Property(e, property));
}
private static Expression SelectStructuralProperties(Expression source, OeSelectItem root)
{
if (!root.HasNavigationItems)
{
return(source);
}
ParameterExpression parameter = Expression.Parameter(OeExpressionHelper.GetCollectionItemType(source.Type));
IReadOnlyList <MemberExpression> joins = OeExpressionHelper.GetPropertyExpressions(parameter);
var newJoins = new Expression[joins.Count];
List <OeSelectItem> navigationItems = FlattenNavigationItems(root, true);
for (int i = 0; i < navigationItems.Count; i++)
{
newJoins[i] = joins[i];
if (navigationItems[i].SelectItems.Count > 0)
{
var properties = new Expression[navigationItems[i].SelectItems.Count];
for (int j = 0; j < navigationItems[i].SelectItems.Count; j++)
{
if (navigationItems[i].SelectItems[j].EdmProperty is ComputeProperty computeProperty)
{
properties[j] = new ReplaceParameterVisitor(joins[i]).Visit(computeProperty.Expression);
}
else
{
PropertyInfo property = OeEdmClrHelper.GetPropertyIgnoreCase(joins[i].Type, navigationItems[i].SelectItems[j].EdmProperty);
properties[j] = Expression.Property(joins[i], property);
}
}
Expression newTupleExpression = OeExpressionHelper.CreateTupleExpression(properties);
if (i > 0 && navigationItems[i].EdmProperty.Type.IsNullable)
{
UnaryExpression nullConstant = Expression.Convert(OeConstantToVariableVisitor.NullConstantExpression, newTupleExpression.Type);
newTupleExpression = Expression.Condition(Expression.Equal(joins[i], OeConstantToVariableVisitor.NullConstantExpression), nullConstant, newTupleExpression);
}
newJoins[i] = newTupleExpression;
}
}
NewExpression newSelectorBody = OeExpressionHelper.CreateTupleExpression(newJoins);
MethodInfo selectMethodInfo = OeMethodInfoHelper.GetSelectMethodInfo(parameter.Type, newSelectorBody.Type);
LambdaExpression newSelector = Expression.Lambda(newSelectorBody, parameter);
//Quirk EF Core 2.1.1 bug Take/Skip must be last in expression tree
var skipTakeExpressions = new List <MethodCallExpression>();
while (source is MethodCallExpression callExpression && (callExpression.Method.Name == nameof(Enumerable.Skip) || callExpression.Method.Name == nameof(Enumerable.Take)))
{
skipTakeExpressions.Add(callExpression);
source = callExpression.Arguments[0];
}
source = Expression.Call(selectMethodInfo, source, newSelector);
for (int i = skipTakeExpressions.Count - 1; i >= 0; i--)
{
MethodInfo skipTakeMethodInfo = skipTakeExpressions[i].Method.GetGenericMethodDefinition().MakeGenericMethod(newSelector.ReturnType);
source = Expression.Call(skipTakeMethodInfo, source, skipTakeExpressions[i].Arguments[1]);
}
return(source);
}