protected Expression ExpandNavigation(
Expression root, EntityReference entityReference, INavigation navigation, bool derivedTypeConversion)
{
if (entityReference.NavigationMap.TryGetValue(navigation, out var expansion))
{
return(expansion);
}
if (navigation.GetTargetType().IsOwned())
{
var ownedEntityReference = new EntityReference(navigation.GetTargetType());
ownedEntityReference.MarkAsOptional();
if (entityReference.IncludePaths.ContainsKey(navigation))
{
ownedEntityReference.SetIncludePaths(entityReference.IncludePaths[navigation]);
}
var ownedExpansion = new OwnedNavigationReference(root, navigation, ownedEntityReference);
if (navigation.IsCollection())
{
return(new MaterializeCollectionNavigationExpression(ownedExpansion, navigation));
}
else
{
entityReference.NavigationMap[navigation] = ownedExpansion;
return(ownedExpansion);
}
}
var innerQueryableType = navigation.GetTargetType().ClrType;
var innerQueryable = NullAsyncQueryProvider.Instance.CreateEntityQueryableExpression(innerQueryableType);
var innerSource = (NavigationExpansionExpression)_navigationExpandingExpressionVisitor.Visit(innerQueryable);
if (entityReference.IncludePaths.ContainsKey(navigation))
{
var innerIncludeTreeNode = entityReference.IncludePaths[navigation];
var innerEntityReference = (EntityReference)((NavigationTreeExpression)innerSource.PendingSelector).Value;
innerEntityReference.SetIncludePaths(innerIncludeTreeNode);
}
var innerParameter = Expression.Parameter(innerSource.SourceElementType, "i");
Expression outerKey;
if (root is NavigationExpansionExpression innerNavigationExpansionExpression &&
innerNavigationExpansionExpression.CardinalityReducingGenericMethodInfo != null)
{
// This is FirstOrDefault ending so we need to push down properties.
var temporaryParameter = Expression.Parameter(root.Type);
var temporaryKey = CreateKeyAccessExpression(temporaryParameter,
navigation.IsDependentToPrincipal()
? navigation.ForeignKey.Properties
: navigation.ForeignKey.PrincipalKey.Properties);
var newSelector = ReplacingExpressionVisitor.Replace(
temporaryParameter,
innerNavigationExpansionExpression.PendingSelector,
temporaryKey);
innerNavigationExpansionExpression.ApplySelector(newSelector);
outerKey = innerNavigationExpansionExpression;
}
protected Expression ExpandNavigation(
Expression root, EntityReference entityReference, INavigation navigation, bool derivedTypeConversion)
{
if (entityReference.NavigationMap.TryGetValue(navigation, out var expansion))
{
return(expansion);
}
var targetType = navigation.TargetEntityType;
if (targetType.HasDefiningNavigation() ||
targetType.IsOwned())
{
var ownedEntityReference = new EntityReference(targetType);
ownedEntityReference.MarkAsOptional();
if (entityReference.IncludePaths.ContainsKey(navigation))
{
ownedEntityReference.SetIncludePaths(entityReference.IncludePaths[navigation]);
}
var ownedExpansion = new OwnedNavigationReference(root, navigation, ownedEntityReference);
if (navigation.IsCollection)
{
var elementType = ownedExpansion.Type.TryGetSequenceType();
var subquery = Expression.Call(
QueryableMethods.AsQueryable.MakeGenericMethod(elementType),
ownedExpansion);
return(new MaterializeCollectionNavigationExpression(subquery, navigation));
}
entityReference.NavigationMap[navigation] = ownedExpansion;
return(ownedExpansion);
}
var innerQueryable = new QueryRootExpression(targetType);
var innerSource = (NavigationExpansionExpression)_navigationExpandingExpressionVisitor.Visit(innerQueryable);
if (entityReference.IncludePaths.ContainsKey(navigation))
{
var innerEntityReference = (EntityReference)((NavigationTreeExpression)innerSource.PendingSelector).Value;
innerEntityReference.SetIncludePaths(entityReference.IncludePaths[navigation]);
}
var innerSourceSequenceType = innerSource.Type.GetSequenceType();
var innerParameter = Expression.Parameter(innerSourceSequenceType, "i");
Expression outerKey;
if (root is NavigationExpansionExpression innerNavigationExpansionExpression &&
innerNavigationExpansionExpression.CardinalityReducingGenericMethodInfo != null)
{
// This is FirstOrDefault ending so we need to push down properties.
var temporaryParameter = Expression.Parameter(root.Type);
var temporaryKey = temporaryParameter.CreateKeyValuesExpression(
navigation.IsOnDependent
? navigation.ForeignKey.Properties
: navigation.ForeignKey.PrincipalKey.Properties,
makeNullable: true);
var newSelector = ReplacingExpressionVisitor.Replace(
temporaryParameter,
innerNavigationExpansionExpression.PendingSelector,
temporaryKey);
innerNavigationExpansionExpression.ApplySelector(newSelector);
outerKey = innerNavigationExpansionExpression;
}
