private static Expression ApplyInterceptors(Expression source, Type elementType, IServiceProvider serviceProvider)
{
var interceptorContainer = new InterceptorContainer(elementType, serviceProvider);
if (interceptorContainer.Any)
{
var parameterExpression = source as ParameterExpression;
if (parameterExpression != null)
{
source = ApplyInterceptorsToProperty(source, elementType, interceptorContainer);
}
var memberExpression = source as MemberExpression;
if (memberExpression != null)
{
var property = memberExpression.Member as PropertyInfo;
if (property == null)
{
var owningType = memberExpression.Type.DeclaringType;
var propertyName = memberExpression.Member.Name;
property = owningType.GetProperty(propertyName);
}
source = typeof(IEnumerable).IsAssignableFrom(property.PropertyType)
? ApplyInterceptorsToCollection(source, elementType, interceptorContainer)
: ApplyInterceptorsToProperty(source, elementType, interceptorContainer);
}
}
return(source);
}
private static Expression ApplyInterceptorsToCollection(Expression source, Type elementType,
InterceptorContainer interceptorContainer)
{
interceptorContainer.ForEach(source, (src, predicate) =>
{
var filterResult = Expression.Call(
ExpressionHelperMethods.EnumerableWhereGeneric.MakeGenericMethod(elementType),
src,
predicate);
source = filterResult;
});
return(source);
}
private static Expression ApplyInterceptorsToProperty(Expression source, Type elementType,
InterceptorContainer interceptorContainer)
{
//return source;
interceptorContainer.ForEach(source, (src, predicate) =>
{
//var m = source as MemberExpression;
//var p = m.Member as PropertyInfo;
////var newExp = PredicateRewriter.RewriteLambda(predicate, src.ToString());
//var methodCall = predicate.Body as MethodCallExpression;
//var n = predicate.Substitute(, source);
//var x = Expression.Lambda(predicate.Body, new[] { Expression.Parameter(m.Expression.Type) }.ToList());
var rewrittenExpression = new ParameterReplacerVisitor(predicate.Parameters[0].Name, src).Visit(predicate.Body);
var filterResult = Expression.Condition(
test: rewrittenExpression,
ifTrue: src,
ifFalse: Expression.Constant(elementType.GetDefault(), elementType),
type: elementType);
source = filterResult;
});
return(source);
}
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("TODO: " /*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 = propertyValue.Type.ToNullable();
Expression nullablePropertyValue = ExpressionHelpers.ToNullable(propertyValue);
Type clrElementType = EdmLibHelpers.GetClrType(elementType, _model);
Expression filterSource = null;
var interceptorContainer = new InterceptorContainer(clrElementType, _serviceProvider);
if ((filterClause != null || interceptorContainer.Any) && property.Type.IsCollection())
{
if (clrElementType == null)
{
throw new ODataException("TODO:" /*Error.Format(SRResources.MappingDoesNotContainResourceType,
* edmElementType.FullName())*/);
}
filterSource =
typeof(IEnumerable).IsAssignableFrom(source.Type.GetProperty(propertyName).PropertyType)
? Expression.Call(
ExpressionHelperMethods.QueryableAsQueryable.MakeGenericMethod(clrElementType),
nullablePropertyValue)
: nullablePropertyValue;
Expression filterPredicate = FilterBinder.Bind(filterClause, clrElementType, _serviceProvider);
MethodCallExpression filterResult = Expression.Call(
ExpressionHelperMethods.QueryableWhereGeneric.MakeGenericMethod(clrElementType),
filterSource,
filterPredicate);
nullablePropertyType = filterResult.Type;
if (_settings.HandleNullPropagation == HandleNullPropagationOption.True)
{
// 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 ((filterClause != null || interceptorContainer.Any) && property.Type.IsCollection())
{
filterSource =
typeof(IEnumerable).IsAssignableFrom(source.Type.GetProperty(propertyName).PropertyType)
? Expression.Call(
ExpressionHelperMethods.QueryableAsQueryable.MakeGenericMethod(clrElementType),
nullablePropertyValue)
: nullablePropertyValue;
}
// TODO: Fix possibly ambiguity resolution if the
// implementation class has multiple methods names
// "Intercept"
var handleNull = false;
source = ApplyInterceptors(source, clrElementType, _serviceProvider);
//interceptorContainer.ForEach(source, (src, predicate) =>
//{
// if (filterSource != null)
// {
// // We have a collection to intercept
// ApplyFilterToQuery(
// clrElementType,
// filterSource,
// predicate,
// ref nullablePropertyType,
// ref nullablePropertyValue);
// }
// else
// {
// handleNull = true;
// // Apply our predicate locally
// nullablePropertyValue = Expression.Condition(
// test: Expression.Invoke(predicate, nullablePropertyValue),
// ifTrue: propertyValue,
// ifFalse: Expression.Constant(value: null, type: nullablePropertyType)
// );
// //ApplyFilterToQuery(
// // clrElementType,
// // propertyValue,
// // predicate,
// // ref nullablePropertyType,
// // ref nullablePropertyValue);
// }
//});
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: 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);
}