protected override Expression VisitMemberInit(MemberInitExpression memberInitExpression)
{
var visitedNew = Visit(memberInitExpression.NewExpression);
var(visitedBindings, entityReferenceInfo) = VisitMemberBindings(memberInitExpression.Bindings);
var visitedMemberInit = memberInitExpression.Update((NewExpression)Unwrap(visitedNew), visitedBindings);
return(entityReferenceInfo == null
? (Expression)visitedMemberInit
: new EntityReferenceExpression(visitedMemberInit, entityReferenceInfo));
// Visits member bindings, unwrapping expressions and surfacing entity reference information via the dictionary
(IEnumerable <MemberBinding>, Dictionary <string, EntityOrDtoType>) VisitMemberBindings(ReadOnlyCollection <MemberBinding> bindings)
{
var newBindings = new MemberBinding[bindings.Count];
Dictionary <string, EntityOrDtoType> bindingEntityReferenceInfo = null;
for (var i = 0; i < bindings.Count; i++)
{
switch (bindings[i])
{
case MemberAssignment assignment:
var visitedAssignment = VisitMemberAssignment(assignment);
if (visitedAssignment.Expression is EntityReferenceExpression ere)
{
if (bindingEntityReferenceInfo == null)
{
bindingEntityReferenceInfo = new Dictionary <string, EntityOrDtoType>();
}
bindingEntityReferenceInfo[assignment.Member.Name] = EntityOrDtoType.FromEntityReferenceExpression(ere);
}
newBindings[i] = assignment.Update(Unwrap(visitedAssignment.Expression));
continue;
default:
newBindings[i] = VisitMemberBinding(bindings[i]);
continue;
}
}
return(newBindings, bindingEntityReferenceInfo);
}
}
protected override Expression VisitNew(NewExpression newExpression)
{
var visitedArgs = Visit(newExpression.Arguments);
var visitedExpression = newExpression.Update(visitedArgs.Select(Unwrap));
// NewExpression.Members is populated for anonymous types, mapping constructor arguments to the properties
// which receive their values. If not populated, a non-anonymous type is being constructed, and we have no idea where
// its constructor arguments will end up.
if (newExpression.Members == null)
{
return(visitedExpression);
}
var entityReferenceInfo = visitedArgs
.Select((a, i) => (Arg: a, Index: i))
.Where(ai => ai.Arg is EntityReferenceExpression)
.ToDictionary(
ai => visitedExpression.Members[ai.Index].Name,
ai => EntityOrDtoType.FromEntityReferenceExpression((EntityReferenceExpression)ai.Arg));
return(entityReferenceInfo.Count == 0
? (Expression)visitedExpression
: new EntityReferenceExpression(visitedExpression, entityReferenceInfo));
}