private static FilterBinder GetOrCreateFilterBinder(ODataQueryContext context, ODataQuerySettings querySettings)
{
FilterBinder binder = null;
if (context.RequestContainer != null)
{
binder = context.RequestContainer.GetRequiredService <FilterBinder>();
if (binder != null && binder.Model != context.Model && binder.Model == EdmCoreModel.Instance)
{
binder.Model = context.Model;
}
}
return(binder ?? new FilterBinder(querySettings, WebApiAssembliesResolver.Default, context.Model));
}
private static LambdaExpression BindFilterClause(FilterBinder binder, FilterClause filterClause, Type filterType)
{
LambdaExpression filter = binder.BindExpression(filterClause.Expression, filterClause.RangeVariable, filterType);
filter = Expression.Lambda(binder.ApplyNullPropagationForFilterBody(filter.Body), filter.Parameters);
Type expectedFilterType = typeof(Func <,>).MakeGenericType(filterType, typeof(bool));
if (filter.Type != expectedFilterType)
{
throw Error.Argument("filterType", SRResources.CannotCastFilter, filter.Type.FullName, expectedFilterType.FullName);
}
return(filter);
}
private Expression AddOrderByQueryForSource(Expression source, OrderByClause orderbyClause, Type elementType)
{
if (orderbyClause != null)
{
// TODO: Implement proper support for $select/$expand after $apply
ODataQuerySettings querySettings = new ODataQuerySettings()
{
HandleNullPropagation = HandleNullPropagationOption.True,
};
LambdaExpression orderByExpression =
FilterBinder.Bind(null, orderbyClause, elementType, _context, querySettings);
source = ExpressionHelpers.OrderBy(source, orderByExpression, elementType, orderbyClause.Direction);
}
return(source);
}
internal static LambdaExpression Bind(
IQueryable baseQuery,
OrderByClause orderBy,
Type elementType,
ODataQueryContext context,
ODataQuerySettings querySettings)
{
Contract.Assert(orderBy != null);
Contract.Assert(elementType != null);
Contract.Assert(context != null);
FilterBinder binder = GetOrCreateFilterBinder(context, querySettings);
binder._filterType = elementType;
binder.BaseQuery = baseQuery;
return(BindOrderByClause(binder, orderBy, elementType));
}
internal static Expression Bind(FilterClause filterClause, Type filterType, IEdmModel model,
IWebApiAssembliesResolver assembliesResolver, ODataQuerySettings querySettings)
{
if (filterClause == null)
{
throw Error.ArgumentNull("filterClause");
}
if (filterType == null)
{
throw Error.ArgumentNull("filterType");
}
if (model == null)
{
throw Error.ArgumentNull("model");
}
if (assembliesResolver == null)
{
throw Error.ArgumentNull("assembliesResolver");
}
FilterBinder binder = new FilterBinder(model, assembliesResolver, querySettings, filterType);
return(BindFilterClause(binder, filterClause, filterType));
}
internal Expression CreatePropertyValueExpressionWithFilter(IEdmEntityType elementType, IEdmProperty property,
Expression source, FilterClause filterClause)
{
Contract.Assert(elementType != null);
Contract.Assert(property != null);
Contract.Assert(source != null);
IEdmEntityType declaringType = property.DeclaringType as IEdmEntityType;
Contract.Assert(declaringType != null, "only entity types are projected.");
// derived property using cast
if (elementType != declaringType)
{
Type castType = EdmLibHelpers.GetClrType(declaringType, _model);
if (castType == null)
{
throw new ODataException(Error.Format(SRResources.MappingDoesNotContainResourceType,
declaringType.FullName()));
}
source = Expression.TypeAs(source, castType);
}
string propertyName = EdmLibHelpers.GetClrPropertyName(property, _model);
Expression propertyValue = Expression.Property(source, propertyName);
Type nullablePropertyType = TypeHelper.ToNullable(propertyValue.Type);
Expression nullablePropertyValue = ExpressionHelpers.ToNullable(propertyValue);
if (filterClause != null)
{
bool isCollection = property.Type.IsCollection();
IEdmTypeReference edmElementType = (isCollection ? property.Type.AsCollection().ElementType() : property.Type);
Type clrElementType = EdmLibHelpers.GetClrType(edmElementType, _model);
if (clrElementType == null)
{
throw new ODataException(Error.Format(SRResources.MappingDoesNotContainResourceType,
edmElementType.FullName()));
}
Expression filterResult = nullablePropertyValue;
ODataQuerySettings querySettings = new ODataQuerySettings()
{
HandleNullPropagation = HandleNullPropagationOption.True,
};
if (isCollection)
{
Expression filterSource =
typeof(IEnumerable).IsAssignableFrom(source.Type.GetProperty(propertyName).PropertyType)
? Expression.Call(
ExpressionHelperMethods.QueryableAsQueryable.MakeGenericMethod(clrElementType),
nullablePropertyValue)
: nullablePropertyValue;
// TODO: Implement proper support for $select/$expand after $apply
Expression filterPredicate = FilterBinder.Bind(null, filterClause, clrElementType, _context, querySettings);
filterResult = Expression.Call(
ExpressionHelperMethods.QueryableWhereGeneric.MakeGenericMethod(clrElementType),
filterSource,
filterPredicate);
nullablePropertyType = filterResult.Type;
}
else if (_settings.HandleReferenceNavigationPropertyExpandFilter)
{
LambdaExpression filterLambdaExpression = FilterBinder.Bind(null, filterClause, clrElementType, _context, querySettings) as LambdaExpression;
if (filterLambdaExpression == null)
{
throw new ODataException(Error.Format(SRResources.ExpandFilterExpressionNotLambdaExpression,
property.Name, "LambdaExpression"));
}
ParameterExpression filterParameter = filterLambdaExpression.Parameters.First();
Expression predicateExpression = new ReferenceNavigationPropertyExpandFilterVisitor(filterParameter, nullablePropertyValue).Visit(filterLambdaExpression.Body);
// create expression similar to: 'predicateExpression == true ? nullablePropertyValue : null'
filterResult = Expression.Condition(
test: predicateExpression,
ifTrue: nullablePropertyValue,
ifFalse: Expression.Constant(value: null, type: nullablePropertyType));
}
if (_settings.HandleNullPropagation == HandleNullPropagationOption.True)
{
// create expression similar to: 'nullablePropertyValue == null ? null : filterResult'
nullablePropertyValue = Expression.Condition(
test: Expression.Equal(nullablePropertyValue, Expression.Constant(value: null)),
ifTrue: Expression.Constant(value: null, type: nullablePropertyType),
ifFalse: filterResult);
}
else
{
nullablePropertyValue = filterResult;
}
}
if (_settings.HandleNullPropagation == HandleNullPropagationOption.True)
{
// create expression similar to: 'source == null ? null : propertyValue'
propertyValue = Expression.Condition(
test: Expression.Equal(source, Expression.Constant(value: null)),
ifTrue: Expression.Constant(value: null, type: nullablePropertyType),
ifFalse: nullablePropertyValue);
}
else
{
// need to cast this to nullable as EF would fail while materializing if the property is not nullable and source is null.
propertyValue = nullablePropertyValue;
}
return(propertyValue);
}
private Expression CreateEntitySetAggregateExpression(
ParameterExpression accum, EntitySetAggregateExpression expression, Type baseType)
{
// Should return following expression
// $it => $it.AsQueryable()
// .SelectMany($it => $it.SomeEntitySet)
// .GroupBy($gr => new Object())
// .Select($p => new DynamicTypeWrapper()
// {
// AliasOne = $p.AsQueryable().AggMethodOne($it => $it.SomePropertyOfSomeEntitySet),
// AliasTwo = $p.AsQueryable().AggMethodTwo($it => $it.AnotherPropertyOfSomeEntitySet),
// ...
// AliasN = ... , // A nested expression of this same format.
// ...
// })
List <MemberAssignment> wrapperTypeMemberAssignments = new List <MemberAssignment>();
var asQueryableMethod = ExpressionHelperMethods.QueryableAsQueryable.MakeGenericMethod(baseType);
Expression asQueryableExpression = Expression.Call(null, asQueryableMethod, accum);
// Create lambda to access the entity set from expression
var source = BindAccessor(expression.Expression.Source);
string propertyName = EdmLibHelpers.GetClrPropertyName(expression.Expression.NavigationProperty, Model);
var property = Expression.Property(source, propertyName);
var baseElementType = source.Type;
var selectedElementType = property.Type.GenericTypeArguments.Single();
// Create method to get property collections to aggregate
MethodInfo selectManyMethod
= ExpressionHelperMethods.EnumerableSelectManyGeneric.MakeGenericMethod(baseElementType, selectedElementType);
// Create the lambda that acceses the property in the selectMany clause.
var selectManyParam = Expression.Parameter(baseElementType, "$it");
var propertyExpression = Expression.Property(selectManyParam, expression.Expression.NavigationProperty.Name);
var selectManyLambda = Expression.Lambda(propertyExpression, selectManyParam);
// Get expression to get collection of entities
var entitySet = Expression.Call(null, selectManyMethod, asQueryableExpression, selectManyLambda);
// Do we have filter from expand to push down?
EnsurePushedDownFilters();
if (_filtersPushDown.TryGetValue(expression.Expression.NavigationSource.Path.Path, out FilterClause filterClause))
{
var filterExpression = FilterBinder.Bind(null, filterClause, selectedElementType, _context, QuerySettings);
var whereMethod = ExpressionHelperMethods.QueryableWhereGeneric.MakeGenericMethod(selectedElementType);
var asNestedQueryableMethod = ExpressionHelperMethods.QueryableAsQueryable.MakeGenericMethod(selectedElementType);
entitySet = Expression.Call(null, whereMethod, Expression.Call(null, asNestedQueryableMethod, entitySet), filterExpression);
}
// Getting method and lambda expression of groupBy
// TODO: We always aggregatin whole collection. Not sure that we really need it
// Using object caused an issue with Linq-to-objects (I replaced by bool )
var groupKeyType = typeof(bool);
MethodInfo groupByMethod =
ExpressionHelperMethods.EnumerableGroupByGeneric.MakeGenericMethod(selectedElementType, groupKeyType);
var groupByLambda = Expression.Lambda(
Expression.New(groupKeyType),
Expression.Parameter(selectedElementType, "$gr"));
// Group entities in a single group to apply select
var groupedEntitySet = Expression.Call(null, groupByMethod, entitySet, groupByLambda);
var groupingType = typeof(IGrouping <,>).MakeGenericType(groupKeyType, selectedElementType);
ParameterExpression innerAccum = Expression.Parameter(groupingType, "$p");
// Nested properties
// Create dynamicTypeWrapper to encapsulate the aggregate result
var properties = new List <NamedPropertyExpression>();
foreach (var aggExpression in expression.Children)
{
properties.Add(new NamedPropertyExpression(Expression.Constant(aggExpression.Alias), CreateAggregationExpression(innerAccum, aggExpression, selectedElementType)));
}
var nestedResultType = typeof(EntitySetAggregationWrapper);
var wrapperProperty = nestedResultType.GetProperty("Container");
wrapperTypeMemberAssignments.Add(Expression.Bind(wrapperProperty, AggregationPropertyContainer.CreateNextNamedPropertyContainer(properties)));
var initializedMember =
Expression.MemberInit(Expression.New(nestedResultType), wrapperTypeMemberAssignments);
var selectLambda = Expression.Lambda(initializedMember, innerAccum);
// Get select method
MethodInfo selectMethod =
ExpressionHelperMethods.EnumerableSelectGeneric.MakeGenericMethod(
groupingType,
selectLambda.Body.Type);
return(Expression.Call(null, selectMethod, groupedEntitySet, selectLambda));
}
private static LambdaExpression BindOrderByClause(FilterBinder binder, OrderByClause orderBy, Type elementType)
{
LambdaExpression orderByLambda = binder.BindExpression(orderBy.Expression, orderBy.RangeVariable, elementType);
return(orderByLambda);
}
internal Expression CreatePropertyValueExpressionWithFilter(IEdmStructuredType elementType, IEdmProperty property,
Expression source, ExpandedReferenceSelectItem expandItem)
{
Contract.Assert(elementType != null);
Contract.Assert(property != null);
Contract.Assert(source != null);
FilterClause filterClause = expandItem != null ? expandItem.FilterOption : null;
IEdmStructuredType declaringType;
IEdmStructuredType currentType = elementType;
if (expandItem != null)
{
foreach (ODataPathSegment segment in expandItem.PathToNavigationProperty)
{
string currentProperty = String.Empty;
PropertySegment propertyAccessPathSegment =
segment as PropertySegment;
if (propertyAccessPathSegment != null)
{
IEdmProperty propertyInPath = propertyAccessPathSegment.Property;
currentProperty = EdmLibHelpers.GetClrPropertyName(propertyInPath, _model);
declaringType = propertyInPath.DeclaringType;
Contract.Assert(!String.IsNullOrEmpty(currentProperty), "Property name could not be found on the model.");
if (_settings.HandleNullPropagation == HandleNullPropagationOption.True)
{
// create expression similar to: 'source == null ? null : propertyValue'
if (declaringType != currentType)
{
Type castType = EdmLibHelpers.GetClrType(property.DeclaringType, _model);
if (castType == null)
{
throw new ODataException(Error.Format(SRResources.MappingDoesNotContainResourceType,
property.DeclaringType.FullTypeName()));
}
source = Expression.TypeAs(source, castType);
}
Expression propertyExpression = Expression.Property(source, currentProperty);
Type nullablePropType = TypeHelper.ToNullable(propertyExpression.Type);
source = Expression.Condition(
test: Expression.Equal(propertyExpression, Expression.Constant(value: null)),
ifTrue: Expression.Constant(value: null, type: nullablePropType),
ifFalse: propertyExpression);
}
else
{
source = Expression.Property(source, currentProperty);
}
currentType = propertyInPath.Type.ToStructuredType();
}
else
{
TypeSegment typeSegment = segment as TypeSegment;
if (typeSegment != null)
{
Type castType = EdmLibHelpers.GetClrType(typeSegment.EdmType, _model);
source = Expression.TypeAs(source, castType);
currentType = typeSegment.EdmType as IEdmStructuredType;
}
}
}
}
// derived property using cast
if (currentType != property.DeclaringType)
{
Type castType = EdmLibHelpers.GetClrType(property.DeclaringType, _model);
if (castType == null)
{
throw new ODataException(Error.Format(SRResources.MappingDoesNotContainResourceType,
property.DeclaringType.FullTypeName()));
}
source = Expression.TypeAs(source, castType);
}
string propertyName = EdmLibHelpers.GetClrPropertyName(property, _model);
PropertyInfo propertyInfo = source.Type.GetProperty(propertyName);
Expression propertyValue = Expression.Property(source, propertyInfo);
Type nullablePropertyType = TypeHelper.ToNullable(propertyValue.Type);
Expression nullablePropertyValue = ExpressionHelpers.ToNullable(propertyValue);
if (filterClause != null)
{
bool isCollection = property.Type.IsCollection();
IEdmTypeReference edmElementType = (isCollection ? property.Type.AsCollection().ElementType() : property.Type);
Type clrElementType = EdmLibHelpers.GetClrType(edmElementType, _model);
if (clrElementType == null)
{
throw new ODataException(Error.Format(SRResources.MappingDoesNotContainResourceType,
edmElementType.FullName()));
}
Expression filterResult = nullablePropertyValue;
ODataQuerySettings querySettings = new ODataQuerySettings()
{
HandleNullPropagation = HandleNullPropagationOption.True,
};
if (isCollection)
{
Expression filterSource = nullablePropertyValue;
// TODO: Implement proper support for $select/$expand after $apply
Expression filterPredicate = FilterBinder.Bind(null, filterClause, clrElementType, _context, querySettings);
filterResult = Expression.Call(
ExpressionHelperMethods.EnumerableWhereGeneric.MakeGenericMethod(clrElementType),
filterSource,
filterPredicate);
nullablePropertyType = filterResult.Type;
}
else if (_settings.HandleReferenceNavigationPropertyExpandFilter)
{
LambdaExpression filterLambdaExpression = FilterBinder.Bind(null, filterClause, clrElementType, _context, querySettings) as LambdaExpression;
if (filterLambdaExpression == null)
{
throw new ODataException(Error.Format(SRResources.ExpandFilterExpressionNotLambdaExpression,
property.Name, "LambdaExpression"));
}
ParameterExpression filterParameter = filterLambdaExpression.Parameters.First();
Expression predicateExpression = new ReferenceNavigationPropertyExpandFilterVisitor(filterParameter, nullablePropertyValue).Visit(filterLambdaExpression.Body);
// create expression similar to: 'predicateExpression == true ? nullablePropertyValue : null'
filterResult = Expression.Condition(
test: predicateExpression,
ifTrue: nullablePropertyValue,
ifFalse: Expression.Constant(value: null, type: nullablePropertyType));
}
if (_settings.HandleNullPropagation == HandleNullPropagationOption.True)
{
// create expression similar to: 'nullablePropertyValue == null ? null : filterResult'
nullablePropertyValue = Expression.Condition(
test: Expression.Equal(nullablePropertyValue, Expression.Constant(value: null)),
ifTrue: Expression.Constant(value: null, type: nullablePropertyType),
ifFalse: filterResult);
}
else
{
nullablePropertyValue = filterResult;
}
}
if (_settings.HandleNullPropagation == HandleNullPropagationOption.True)
{
// create expression similar to: 'source == null ? null : propertyValue'
propertyValue = Expression.Condition(
test: Expression.Equal(source, Expression.Constant(value: null)),
ifTrue: Expression.Constant(value: null, type: nullablePropertyType),
ifFalse: nullablePropertyValue);
}
else
{
// need to cast this to nullable as EF would fail while materializing if the property is not nullable and source is null.
propertyValue = nullablePropertyValue;
}
return(propertyValue);
}
