public static NavigationExpansionExpression CreateNavigationExpansionRoot(
Expression operand,
IEntityType entityType,
INavigation materializeCollectionNavigation)
{
var sourceMapping = new SourceMapping
{
RootEntityType = entityType,
};
var navigationTreeRoot = NavigationTreeNode.CreateRoot(sourceMapping, fromMapping: new List <string>(), optional: false);
sourceMapping.NavigationTree = navigationTreeRoot;
var pendingSelectorParameter = Expression.Parameter(entityType.ClrType);
var pendingSelector = Expression.Lambda(
new NavigationBindingExpression(
pendingSelectorParameter,
navigationTreeRoot,
entityType,
sourceMapping,
pendingSelectorParameter.Type),
pendingSelectorParameter);
return(new NavigationExpansionExpression(
operand,
new NavigationExpansionExpressionState(
pendingSelectorParameter,
new List <SourceMapping> {
sourceMapping
},
pendingSelector,
applyPendingSelector: false,
new List <(MethodInfo method, LambdaExpression keySelector)>(),
pendingIncludeChain: null,
pendingCardinalityReducingOperator: null,
customRootMappings: new List <List <string> >(),
materializeCollectionNavigation),
materializeCollectionNavigation?.ClrType ?? operand.Type));
}
public static void CopyIncludeInformation(NavigationTreeNode originalNavigationTree, NavigationTreeNode newNavigationTree, SourceMapping newSourceMapping)
{
foreach (var child in originalNavigationTree.Children.Where(n => n.IncludeState == NavigationState.Pending))
{
var copy = NavigationTreeNode.Create(newSourceMapping, child.Navigation, newNavigationTree, true);
CopyIncludeInformation(child, copy, newSourceMapping);
}
}
public static (Expression Source, ParameterExpression Parameter) AddNavigationJoin(
Expression sourceExpression,
ParameterExpression parameterExpression,
SourceMapping sourceMapping,
NavigationTreeNode navigationTree,
NavigationExpansionExpressionState state,
List <INavigation> navigationPath,
bool include)
{
var joinNeeded = include
? navigationTree.IncludeState == NavigationState.Pending
: navigationTree.ExpansionState == NavigationState.Pending;
if (joinNeeded)
{
var navigation = navigationTree.Navigation;
var sourceType = sourceExpression.Type.GetSequenceType();
var navigationTargetEntityType = navigation.GetTargetType();
var entityQueryable = NullAsyncQueryProvider.Instance.CreateEntityQueryableExpression(navigationTargetEntityType.ClrType);
var resultType = typeof(TransparentIdentifier <,>).MakeGenericType(sourceType, navigationTargetEntityType.ClrType);
var outerParameter = Expression.Parameter(sourceType, parameterExpression.Name);
var outerKeySelectorParameter = outerParameter;
var transparentIdentifierAccessorExpression = outerParameter.BuildPropertyAccess(navigationTree.Parent.ToMapping);
var outerKeySelectorBody = CreateKeyAccessExpression(
transparentIdentifierAccessorExpression,
navigation.IsDependentToPrincipal()
? navigation.ForeignKey.Properties
: navigation.ForeignKey.PrincipalKey.Properties,
addNullCheck: navigationTree.Parent != null && navigationTree.Parent.Optional);
var innerKeySelectorParameterType = navigationTargetEntityType.ClrType;
var innerKeySelectorParameter = Expression.Parameter(
innerKeySelectorParameterType,
parameterExpression.Name + "." + navigationTree.Navigation.Name);
var innerKeySelectorBody = CreateKeyAccessExpression(
innerKeySelectorParameter,
navigation.IsDependentToPrincipal()
? navigation.ForeignKey.PrincipalKey.Properties
: navigation.ForeignKey.Properties);
if (outerKeySelectorBody.Type.IsNullableType() &&
!innerKeySelectorBody.Type.IsNullableType())
{
innerKeySelectorBody = Expression.Convert(innerKeySelectorBody, outerKeySelectorBody.Type);
}
else if (innerKeySelectorBody.Type.IsNullableType() &&
!outerKeySelectorBody.Type.IsNullableType())
{
outerKeySelectorBody = Expression.Convert(outerKeySelectorBody, innerKeySelectorBody.Type);
}
var outerKeySelector = Expression.Lambda(
outerKeySelectorBody,
outerKeySelectorParameter);
var innerKeySelector = Expression.Lambda(
innerKeySelectorBody,
innerKeySelectorParameter);
if (!sourceExpression.Type.IsQueryableType())
{
var asQueryableMethodInfo = LinqMethodHelpers.AsQueryable.MakeGenericMethod(sourceType);
sourceExpression = Expression.Call(asQueryableMethodInfo, sourceExpression);
}
var joinMethodInfo = navigationTree.Optional
? _leftJoinMethodInfo.MakeGenericMethod(
sourceType,
navigationTargetEntityType.ClrType,
outerKeySelector.Body.Type,
resultType)
: LinqMethodHelpers.QueryableJoinMethodInfo.MakeGenericMethod(
sourceType,
navigationTargetEntityType.ClrType,
outerKeySelector.Body.Type,
resultType);
var resultSelectorOuterParameterName = outerParameter.Name;
var resultSelectorOuterParameter = Expression.Parameter(sourceType, resultSelectorOuterParameterName);
var resultSelectorInnerParameterName = innerKeySelectorParameter.Name;
var resultSelectorInnerParameter = Expression.Parameter(navigationTargetEntityType.ClrType, resultSelectorInnerParameterName);
var transparentIdentifierCtorInfo
= resultType.GetTypeInfo().GetConstructors().Single();
var transparentIdentifierOuterMemberInfo = resultType.GetTypeInfo().GetDeclaredField("Outer");
var transparentIdentifierInnerMemberInfo = resultType.GetTypeInfo().GetDeclaredField("Inner");
var resultSelector = Expression.Lambda(
Expression.New(
transparentIdentifierCtorInfo,
new[] { resultSelectorOuterParameter, resultSelectorInnerParameter },
new[] { transparentIdentifierOuterMemberInfo, transparentIdentifierInnerMemberInfo }),
resultSelectorOuterParameter,
resultSelectorInnerParameter);
var joinMethodCall = Expression.Call(
joinMethodInfo,
sourceExpression,
entityQueryable,
outerKeySelector,
innerKeySelector,
resultSelector);
sourceExpression = joinMethodCall;
var transparentIdentifierParameterName = resultSelectorInnerParameterName;
var transparentIdentifierParameter = Expression.Parameter(resultSelector.ReturnType, transparentIdentifierParameterName);
parameterExpression = transparentIdentifierParameter;
// remap navigation 'To' paths -> for this navigation prepend "Inner", for every other (already expanded) navigation prepend "Outer"
navigationTree.ToMapping.Insert(0, nameof(TransparentIdentifier <object, object> .Inner));
foreach (var mapping in state.SourceMappings)
{
var nodes = include
? mapping.NavigationTree.Flatten().Where(n => (n.IncludeState == NavigationState.Complete ||
n.ExpansionState == NavigationState.Complete ||
n.Navigation.ForeignKey.IsOwnership) &&
n != navigationTree)
: mapping.NavigationTree.Flatten().Where(n => (n.ExpansionState == NavigationState.Complete ||
n.Navigation.ForeignKey.IsOwnership) &&
n != navigationTree);
foreach (var navigationTreeNode in nodes)
{
navigationTreeNode.ToMapping.Insert(0, nameof(TransparentIdentifier <object, object> .Outer));
}
}
foreach (var customRootMapping in state.CustomRootMappings)
{
customRootMapping.Insert(0, nameof(TransparentIdentifier <object, object> .Outer));
}
if (include)
{
navigationTree.IncludeState = NavigationState.Complete;
}
else
{
navigationTree.ExpansionState = NavigationState.Complete;
}
navigationPath.Add(navigation);
}
else
{
navigationPath.Add(navigationTree.Navigation);
}
var result = (Source : sourceExpression, Parameter : parameterExpression);
foreach (var child in navigationTree.Children.Where(n => !n.IsCollection))
{
result = AddNavigationJoin(
result.Source,
result.Parameter,
sourceMapping,
child,
state,
navigationPath.ToList(),
include);
}
return(result);
}
public static Expression CreateCollectionNavigationExpression(
NavigationTreeNode navigationTreeNode, ParameterExpression rootParameter, SourceMapping sourceMapping)
{
var collectionEntityType = navigationTreeNode.Navigation.ForeignKey.DeclaringEntityType;
Expression operand;
if (navigationTreeNode.IncludeState == NavigationState.Pending ||
navigationTreeNode.ExpansionState == NavigationState.Pending)
{
var entityQueryable = (Expression)NullAsyncQueryProvider.Instance.CreateEntityQueryableExpression(collectionEntityType.ClrType);
var outerBinding = new NavigationBindingExpression(
rootParameter,
navigationTreeNode.Parent,
navigationTreeNode.Navigation.DeclaringEntityType,
sourceMapping,
navigationTreeNode.Navigation.DeclaringEntityType.ClrType);
var outerKeyAccess = NavigationExpansionHelpers.CreateKeyAccessExpression(
outerBinding,
navigationTreeNode.Navigation.ForeignKey.PrincipalKey.Properties,
addNullCheck: outerBinding.NavigationTreeNode.Optional);
var collectionCurrentParameter = Expression.Parameter(
collectionEntityType.ClrType, collectionEntityType.ClrType.GenerateParameterName());
var innerKeyAccess = NavigationExpansionHelpers.CreateKeyAccessExpression(
collectionCurrentParameter,
navigationTreeNode.Navigation.ForeignKey.Properties);
var predicate = Expression.Lambda(
CreateKeyComparisonExpressionForCollectionNavigationSubquery(
outerKeyAccess,
innerKeyAccess,
outerBinding),
collectionCurrentParameter);
operand = Expression.Call(
LinqMethodHelpers.QueryableWhereMethodInfo.MakeGenericMethod(collectionEntityType.ClrType),
entityQueryable,
predicate);
}
else
{
operand = new NavigationBindingExpression(
rootParameter,
navigationTreeNode,
collectionEntityType,
sourceMapping,
collectionEntityType.ClrType);
}
var result = NavigationExpansionHelpers.CreateNavigationExpansionRoot(
operand, collectionEntityType, navigationTreeNode.Navigation);
// this is needed for cases like: root.Include(r => r.Collection).ThenInclude(c => c.Reference).Select(r => r.Collection)
// result should be elements of the collection navigation with their 'Reference' included
var newSourceMapping = result.State.SourceMappings.Single();
IncludeHelpers.CopyIncludeInformation(navigationTreeNode, newSourceMapping.NavigationTree, newSourceMapping);
return(result);
}
