/// <summary>
/// This is an internal API that supports the Entity Framework Core infrastructure and not subject to
/// the same compatibility standards as public APIs. It may be changed or removed without notice in
/// any release. You should only use it directly in your code with extreme caution and knowing that
/// doing so can result in application failures when updating to a new Entity Framework Core release.
/// </summary>
protected override Expression VisitExtension(Expression extensionExpression)
{
Check.NotNull(extensionExpression, nameof(extensionExpression));
switch (extensionExpression)
{
case EntityShaperExpression entityShaperExpression:
{
var projectionBindingExpression = (ProjectionBindingExpression)entityShaperExpression.ValueBufferExpression;
VerifySelectExpression(projectionBindingExpression);
if (_clientEval)
{
var entityProjection = (EntityProjectionExpression)_selectExpression.GetMappedProjection(
projectionBindingExpression.ProjectionMember);
return(entityShaperExpression.Update(
new ProjectionBindingExpression(
_selectExpression, _selectExpression.AddToProjection(entityProjection), typeof(ValueBuffer))));
}
_projectionMapping[_projectionMembers.Peek()]
= _selectExpression.GetMappedProjection(projectionBindingExpression.ProjectionMember);
return(entityShaperExpression.Update(
new ProjectionBindingExpression(_selectExpression, _projectionMembers.Peek(), typeof(ValueBuffer))));
}
case MaterializeCollectionNavigationExpression materializeCollectionNavigationExpression:
return(materializeCollectionNavigationExpression.Navigation is INavigation embeddableNavigation &&
embeddableNavigation.IsEmbedded()
? base.Visit(materializeCollectionNavigationExpression.Subquery)
: base.VisitExtension(materializeCollectionNavigationExpression));
case IncludeExpression includeExpression:
if (!_clientEval)
{
return(null);
}
if (!(includeExpression.Navigation is INavigation includableNavigation &&
includableNavigation.IsEmbedded()))
{
throw new InvalidOperationException(
CosmosStrings.NonEmbeddedIncludeNotSupported(includeExpression.Navigation));
}
_includedNavigations.Push(includableNavigation);
var newIncludeExpression = base.VisitExtension(includeExpression);
_includedNavigations.Pop();
return(newIncludeExpression);
default:
throw new InvalidOperationException(CoreStrings.TranslationFailed(extensionExpression.Print()));
}
}
protected override Expression VisitMethodCall(MethodCallExpression methodCallExpression)
{
Check.NotNull(methodCallExpression, nameof(methodCallExpression));
var method = methodCallExpression.Method;
var genericMethod = method.IsGenericMethod ? method.GetGenericMethodDefinition() : null;
if (genericMethod == EntityFrameworkCore.Infrastructure.ExpressionExtensions.ValueBufferTryReadValueMethod)
{
var property = methodCallExpression.Arguments[2].GetConstantValue <IProperty>();
Expression innerExpression;
if (methodCallExpression.Arguments[0] is ProjectionBindingExpression projectionBindingExpression)
{
var projection = GetProjection(projectionBindingExpression);
innerExpression = Expression.Convert(
CreateReadJTokenExpression(_jObjectParameter, projection.Alias),
typeof(JObject));
}
else
{
innerExpression = _materializationContextBindings[
(ParameterExpression)((MethodCallExpression)methodCallExpression.Arguments[0]).Object];
}
return(CreateGetValueExpression(innerExpression, property, methodCallExpression.Type));
}
if (method.DeclaringType == typeof(Enumerable) &&
method.Name == nameof(Enumerable.Select) &&
genericMethod == EnumerableMethods.Select)
{
var lambda = (LambdaExpression)methodCallExpression.Arguments[1];
if (lambda.Body is IncludeExpression includeExpression)
{
if (!(includeExpression.Navigation is INavigation navigation) ||
navigation.IsOnDependent ||
navigation.ForeignKey.DeclaringEntityType.IsDocumentRoot())
{
throw new InvalidOperationException(
CosmosStrings.NonEmbeddedIncludeNotSupported(includeExpression.Navigation));
}
_pendingIncludes.Add(includeExpression);
Visit(includeExpression.EntityExpression);
// Includes on collections are processed when visiting CollectionShaperExpression
return(Visit(methodCallExpression.Arguments[0]));
}
}
return(base.VisitMethodCall(methodCallExpression));
}
protected override Expression VisitExtension(Expression extensionExpression)
{
Check.NotNull(extensionExpression, nameof(extensionExpression));
switch (extensionExpression)
{
case ProjectionBindingExpression projectionBindingExpression:
{
var projection = GetProjection(projectionBindingExpression);
return(CreateGetValueExpression(
_jObjectParameter,
projection.Alias,
projectionBindingExpression.Type, (projection.Expression as SqlExpression)?.TypeMapping));
}
case CollectionShaperExpression collectionShaperExpression:
{
ObjectArrayProjectionExpression objectArrayProjection;
switch (collectionShaperExpression.Projection)
{
case ProjectionBindingExpression projectionBindingExpression:
var projection = GetProjection(projectionBindingExpression);
objectArrayProjection = (ObjectArrayProjectionExpression)projection.Expression;
break;
case ObjectArrayProjectionExpression objectArrayProjectionExpression:
objectArrayProjection = objectArrayProjectionExpression;
break;
default:
throw new InvalidOperationException(CoreStrings.TranslationFailed(extensionExpression.Print()));
}
var jArray = _projectionBindings[objectArrayProjection];
var jObjectParameter = Expression.Parameter(typeof(JObject), jArray.Name + "Object");
var ordinalParameter = Expression.Parameter(typeof(int), jArray.Name + "Ordinal");
var accessExpression = objectArrayProjection.InnerProjection.AccessExpression;
_projectionBindings[accessExpression] = jObjectParameter;
_ownerMappings[accessExpression] =
(objectArrayProjection.Navigation.DeclaringEntityType, objectArrayProjection.AccessExpression);
_ordinalParameterBindings[accessExpression] = Expression.Add(
ordinalParameter, Expression.Constant(1, typeof(int)));
var innerShaper = (BlockExpression)Visit(collectionShaperExpression.InnerShaper);
innerShaper = AddIncludes(innerShaper);
var entities = Expression.Call(
EnumerableMethods.SelectWithOrdinal.MakeGenericMethod(typeof(JObject), innerShaper.Type),
Expression.Call(
EnumerableMethods.Cast.MakeGenericMethod(typeof(JObject)),
jArray),
Expression.Lambda(innerShaper, jObjectParameter, ordinalParameter));
var navigation = collectionShaperExpression.Navigation;
return(Expression.Call(
_populateCollectionMethodInfo.MakeGenericMethod(navigation.TargetEntityType.ClrType, navigation.ClrType),
Expression.Constant(navigation.GetCollectionAccessor()),
entities));
}
case IncludeExpression includeExpression:
{
if (!(includeExpression.Navigation is INavigation navigation) ||
navigation.IsOnDependent ||
navigation.ForeignKey.DeclaringEntityType.IsDocumentRoot())
{
throw new InvalidOperationException(
CosmosStrings.NonEmbeddedIncludeNotSupported(includeExpression.Navigation));
}
var isFirstInclude = _pendingIncludes.Count == 0;
_pendingIncludes.Add(includeExpression);
var jObjectBlock = Visit(includeExpression.EntityExpression) as BlockExpression;
if (!isFirstInclude)
{
return(jObjectBlock);
}
Check.DebugAssert(jObjectBlock != null, "The first include must end up on a valid shaper block");
// These are the expressions added by JObjectInjectingExpressionVisitor
var jObjectCondition = (ConditionalExpression)jObjectBlock.Expressions[^ 1];