private static Type GetNamedPropertyType(NamedPropertyExpression property, IList <Expression> expressions)
{
Type namedPropertyGenericType;
if (property.NullCheck != null)
{
namedPropertyGenericType = SingleExpandedPropertyTypes[expressions.Count];
}
else if (property.PageSize != null || property.CountOption != null)
{
namedPropertyGenericType = CollectionExpandedPropertyTypes[expressions.Count];
}
else if (property.AutoSelected)
{
namedPropertyGenericType = AutoSelectedNamedPropertyTypes[expressions.Count];
}
else
{
namedPropertyGenericType = NamedPropertyTypes[expressions.Count];
}
Type elementType = (property.PageSize == null && property.CountOption == null)
? property.Value.Type
: TypeHelper.GetInnerElementType(property.Value.Type);
return(namedPropertyGenericType.MakeGenericType(elementType));
}
private static Expression CreateNextNamedPropertyCreationExpression(NamedPropertyExpression property, Expression next)
{
Contract.Assert(property != null);
Contract.Assert(property.Value != null);
Type namedPropertyType = null;
if (next != null)
{
if (property.Value.Type == typeof(GroupByWrapper))
{
namedPropertyType = typeof(NestedProperty);
}
else
{
namedPropertyType = typeof(AggregationPropertyContainer);
}
}
else
{
if (property.Value.Type == typeof(GroupByWrapper))
{
namedPropertyType = typeof(NestedPropertyLastInChain);
}
else
{
namedPropertyType = typeof(LastInChain);
}
}
List <MemberBinding> memberBindings = new List <MemberBinding>();
memberBindings.Add(Expression.Bind(namedPropertyType.GetProperty("Name"), property.Name));
if (property.Value.Type == typeof(GroupByWrapper))
{
memberBindings.Add(Expression.Bind(namedPropertyType.GetProperty("NestedValue"), property.Value));
}
else
{
memberBindings.Add(Expression.Bind(namedPropertyType.GetProperty("Value"), property.Value));
}
if (next != null)
{
memberBindings.Add(Expression.Bind(namedPropertyType.GetProperty("Next"), next));
}
if (property.NullCheck != null)
{
memberBindings.Add(Expression.Bind(namedPropertyType.GetProperty("IsNull"), property.NullCheck));
}
return(Expression.MemberInit(Expression.New(namedPropertyType), memberBindings));
}
// Expression:
// new NamedProperty<T> { Name = property.Name, Value = property.Value, Next0 = next0, Next1 = next1, .... }.
private static Expression CreateNamedPropertyCreationExpression(NamedPropertyExpression property, IList <Expression> expressions)
{
Contract.Assert(property != null);
Contract.Assert(property.Value != null);
Type namedPropertyType = GetNamedPropertyType(property, expressions);
List <MemberBinding> memberBindings = new List <MemberBinding>();
memberBindings.Add(Expression.Bind(namedPropertyType.GetProperty("Name"), property.Name));
if (property.PageSize != null || property.CountOption != null)
{
memberBindings.Add(Expression.Bind(namedPropertyType.GetProperty("Collection"), property.Value));
if (property.PageSize != null)
{
memberBindings.Add(Expression.Bind(namedPropertyType.GetProperty("PageSize"),
Expression.Constant(property.PageSize)));
}
if (property.CountOption != null && property.CountOption.Value)
{
memberBindings.Add(Expression.Bind(namedPropertyType.GetProperty("TotalCount"), ExpressionHelpers.ToNullable(property.TotalCount)));
}
}
else
{
memberBindings.Add(Expression.Bind(namedPropertyType.GetProperty("Value"), property.Value));
}
for (int i = 0; i < expressions.Count; i++)
{
memberBindings.Add(Expression.Bind(namedPropertyType.GetProperty("Next" + i), expressions[i]));
}
if (property.NullCheck != null)
{
memberBindings.Add(Expression.Bind(namedPropertyType.GetProperty("IsNull"), property.NullCheck));
}
return(Expression.MemberInit(Expression.New(namedPropertyType), memberBindings));
}
// Expression:
// new NamedProperty<T>
// {
// Name = properties[0].Key,
// Value = properties[0].Value,
//
// Next0 = new NamedProperty<> { ..... }
// Next1 = new NamedProperty<> { ..... },
// ...
// }
public static Expression CreatePropertyContainer(IList <NamedPropertyExpression> properties)
{
Expression container = null;
// build the linked list of properties.
if (properties.Count >= 1)
{
NamedPropertyExpression property = properties.First();
int count = properties.Count - 1;
List <Expression> nextExpressions = new List <Expression>();
int parts = SingleExpandedPropertyTypes.Count - 1;
int offset = 0;
for (int step = parts; step > 0; step--)
{
int leftSize = GetLeftSize(count - offset, step);
nextExpressions.Add(CreatePropertyContainer(properties.Skip(1 + offset).Take(leftSize).ToList()));
offset += leftSize;
}
container = CreateNamedPropertyCreationExpression(property, nextExpressions.Where(e => e != null).ToList());
}
return(container);
}
/// <summary>
/// Pre flattens properties referenced in aggregate clause to avoid generation of nested queries by EF.
/// For query like groupby((A), aggregate(B/C with max as Alias1, B/D with max as Alias2)) we need to generate
/// .Select(
/// $it => new FlattenninWrapper () {
/// Source = $it, // Will used in groupby stage
/// Container = new {
/// Value = $it.B.C
/// Next = new {
/// Value = $it.B.D
/// }
/// }
/// }
/// )
/// Also we need to populate expressions to access B/C and B/D in aggregate stage. It will look like:
/// B/C : $it.Container.Value
/// B/D : $it.Container.Next.Value
/// </summary>
/// <param name="query"></param>
/// <returns>Query with Select that flattens properties</returns>
private IQueryable FlattenReferencedProperties(IQueryable query)
{
if (_aggregateExpressions != null &&
_aggregateExpressions.OfType <AggregateExpression>().Any(e => e.Method != AggregationMethod.VirtualPropertyCount) &&
_groupingProperties != null &&
_groupingProperties.Any() &&
(FlattenedPropertyContainer == null || !FlattenedPropertyContainer.Any()))
{
var wrapperType = typeof(FlatteningWrapper <>).MakeGenericType(this._elementType);
var sourceProperty = wrapperType.GetProperty("Source");
List <MemberAssignment> wta = new List <MemberAssignment>();
wta.Add(Expression.Bind(sourceProperty, this._lambdaParameter));
var aggrregatedPropertiesToFlatten = _aggregateExpressions.OfType <AggregateExpression>().Where(e => e.Method != AggregationMethod.VirtualPropertyCount).ToList();
// Generated Select will be stack like, meaning that first property in the list will be deepest one
// For example if we add $it.B.C, $it.B.D, select will look like
// new {
// Value = $it.B.C
// Next = new {
// Value = $it.B.D
// }
// }
// We are generated references (in currentContainerExpression) from the begining of the Select ($it.Value, then $it.Next.Value etc.)
// We have proper match we need insert properties in reverse order
// After this
// properties = { $it.B.D, $it.B.C}
// _preFlattendMAp = { {$it.B.C, $it.Value}, {$it.B.D, $it.Next.Value} }
var properties = new NamedPropertyExpression[aggrregatedPropertiesToFlatten.Count];
var aliasIdx = aggrregatedPropertiesToFlatten.Count - 1;
var aggParam = Expression.Parameter(wrapperType, "$it");
var currentContainerExpression = Expression.Property(aggParam, GroupByContainerProperty);
foreach (var aggExpression in aggrregatedPropertiesToFlatten)
{
var alias = "Property" + aliasIdx.ToString(CultureInfo.CurrentCulture); // We just need unique alias, we aren't going to use it
// Add Value = $it.B.C
var propAccessExpression = BindAccessor(aggExpression.Expression);
var type = propAccessExpression.Type;
propAccessExpression = WrapConvert(propAccessExpression);
properties[aliasIdx] = new NamedPropertyExpression(Expression.Constant(alias), propAccessExpression);
// Save $it.Container.Next.Value for future use
UnaryExpression flatAccessExpression = Expression.Convert(
Expression.Property(currentContainerExpression, "Value"),
type);
currentContainerExpression = Expression.Property(currentContainerExpression, "Next");
_preFlattenedMap.Add(aggExpression.Expression, flatAccessExpression);
aliasIdx--;
}
var wrapperProperty = ResultClrType.GetProperty(GroupByContainerProperty);
wta.Add(Expression.Bind(wrapperProperty, AggregationPropertyContainer.CreateNextNamedPropertyContainer(properties)));
var flatLambda = Expression.Lambda(Expression.MemberInit(Expression.New(wrapperType), wta), _lambdaParameter);
query = ExpressionHelpers.Select(query, flatLambda, this._elementType);
// We applied flattening let .GroupBy know about it.
this._lambdaParameter = aggParam;
this._elementType = wrapperType;
}
return(query);
}
private Expression BuildPropertyContainer(IEdmEntityType elementType, Expression source,
Dictionary <IEdmNavigationProperty, ExpandedReferenceSelectItem> propertiesToExpand,
ISet <IEdmStructuralProperty> propertiesToInclude, ISet <IEdmStructuralProperty> autoSelectedProperties, bool isSelectingOpenTypeSegments)
{
IList <NamedPropertyExpression> includedProperties = new List <NamedPropertyExpression>();
foreach (KeyValuePair <IEdmNavigationProperty, ExpandedReferenceSelectItem> kvp in propertiesToExpand)
{
IEdmNavigationProperty propertyToExpand = kvp.Key;
ExpandedReferenceSelectItem expandItem = kvp.Value;
SelectExpandClause projection = GetOrCreateSelectExpandClause(kvp);
ModelBoundQuerySettings querySettings = EdmLibHelpers.GetModelBoundQuerySettings(propertyToExpand,
propertyToExpand.ToEntityType(),
_context.Model);
Expression propertyName = CreatePropertyNameExpression(elementType, propertyToExpand, source);
Expression propertyValue = CreatePropertyValueExpressionWithFilter(elementType, propertyToExpand, source,
expandItem.FilterOption);
Expression nullCheck = GetNullCheckExpression(propertyToExpand, propertyValue, projection);
Expression countExpression = CreateTotalCountExpression(propertyValue, expandItem);
// projection can be null if the expanded navigation property is not further projected or expanded.
if (projection != null)
{
int?modelBoundPageSize = querySettings == null ? null : querySettings.PageSize;
propertyValue = ProjectAsWrapper(propertyValue, projection, propertyToExpand.ToEntityType(), expandItem.NavigationSource, expandItem, modelBoundPageSize);
}
NamedPropertyExpression propertyExpression = new NamedPropertyExpression(propertyName, propertyValue);
if (projection != null)
{
if (!propertyToExpand.Type.IsCollection())
{
propertyExpression.NullCheck = nullCheck;
}
else if (_settings.PageSize.HasValue)
{
propertyExpression.PageSize = _settings.PageSize.Value;
}
else
{
if (querySettings != null && querySettings.PageSize.HasValue)
{
propertyExpression.PageSize = querySettings.PageSize.Value;
}
}
propertyExpression.TotalCount = countExpression;
propertyExpression.CountOption = expandItem.CountOption;
}
includedProperties.Add(propertyExpression);
}
foreach (IEdmStructuralProperty propertyToInclude in propertiesToInclude)
{
Expression propertyName = CreatePropertyNameExpression(elementType, propertyToInclude, source);
Expression propertyValue = CreatePropertyValueExpression(elementType, propertyToInclude, source);
includedProperties.Add(new NamedPropertyExpression(propertyName, propertyValue));
}
foreach (IEdmStructuralProperty propertyToInclude in autoSelectedProperties)
{
Expression propertyName = CreatePropertyNameExpression(elementType, propertyToInclude, source);
Expression propertyValue = CreatePropertyValueExpression(elementType, propertyToInclude, source);
includedProperties.Add(new NamedPropertyExpression(propertyName, propertyValue)
{
AutoSelected = true
});
}
if (isSelectingOpenTypeSegments)
{
var dynamicPropertyDictionary = EdmLibHelpers.GetDynamicPropertyDictionary(elementType, _model);
if (dynamicPropertyDictionary != null)
{
Expression propertyName = Expression.Constant(dynamicPropertyDictionary.Name);
Expression propertyValue = Expression.Property(source, dynamicPropertyDictionary.Name);
Expression nullablePropertyValue = ExpressionHelpers.ToNullable(propertyValue);
if (_settings.HandleNullPropagation == HandleNullPropagationOption.True)
{
// source == null ? null : propertyValue
propertyValue = Expression.Condition(
test: Expression.Equal(source, Expression.Constant(value: null)),
ifTrue: Expression.Constant(value: null, type: TypeHelper.ToNullable(propertyValue.Type)),
ifFalse: nullablePropertyValue);
}
else
{
propertyValue = nullablePropertyValue;
}
includedProperties.Add(new NamedPropertyExpression(propertyName, propertyValue));
}
}
// create a property container that holds all these property names and values.
return(PropertyContainer.CreatePropertyContainer(includedProperties));
}
