Version 9.0: List<int> seems to always be nulled in transit

[rsemparnell]

Describe the bug
One of my business objects has a List property. It appears to always be lost by the serializer - while my Create() method is RunLocal, the call to Insert() results in a null reference exception when the property is encountered. Even explicitly initializing and optionally setting a test value still results in a null.

The upgrading to v9 document seems to imply that List is explicitly supported?

Version and Platform
CSLA version: 9.0.0
OS: Windows
Platform: ASP.NET Core MVC

Code that Fails

public static readonly PropertyInfo<List<int>> AllowedPurposeIdsProperty = 
    RegisterProperty<List<int>>(c => c.AllowedPurposeIds);

public List<int> AllowedPurposeIds
{
    get => GetProperty(AllowedPurposeIdsProperty);
    set => SetProperty(AllowedPurposeIdsProperty, value);
}

Then the code that sets it:

var NewFolderObj = dataPortalFactory.GetPortal<FileFolder>().Create();
NewFolderObj.FolderName = entry.Name;
NewFolderObj.ModuleID = ModuleID;
NewFolderObj.GroupID = GroupID;
NewFolderObj.Deleted = false;
NewFolderObj.FolderOwnerID = FolderOwnerID;
NewFolderObj.AllowedPurposeIds = AllowedPurposeIds.ToList(); // stored locally as an array for annoying reasons

if (NewFolderObj.IsSavable)
{
    await NewFolderObj.SaveAndMergeAsync();
...

Stack Trace or Exception Detail
When I replaced the object with a string property, it works, but this is not ideal for type safety.

Additional context
Add any other context about the problem here.

[StefanOssendorf]

Hi. List<T> is not serializable. You have to use MobileList<T> to get a list serialized. Same holds for MovileDictionary

[rsemparnell]

Hi. List<T> is not serializable. You have to use MobileList<T> to get a list serialized. Same holds for MovileDictionary

The documentation implies otherwise? A couple of my other objects use List<string> and List<int> and don't appear to be failing, but those are only being loaded up from the dal, not edited. This pitfall appears only to be on the client side when the client is setting or modifying the property. If it is not supported, but yet is implied that this type as a primitive should be, perhaps the v9 doc needs adjusted?

Also sorry for the lack of pleasantries, I tend to be very dry and emotionless when I'm working - so hello, all.

How you implement these methods is up to you, but you should be aware that the SerializationInfo class is a key/value store,
 so you can store any "primitive" data in it that can be normally serialized using MobileFormatter.

This includes:

All .NET primitive types
string
DateTime, TimeSpan, DateTimeOffset, DateOnly, TimeOnly
Guid
byte[]
char[]
List<int>

[StefanOssendorf]

You are correct. The docs suggest that but I think this is out of the box not possible. Maybe @rockfordlhotka can shed some light on it. He wrote the new doc section :D

Nevertheless with MobileList it should definitely work.

Anyway I'll try your code if there's a bug.
Could you please elaborate on the cases where it works? How's the object defined and which ways are the lists being sent?
Thanks in advance

[rsemparnell]

Ha! Yeah a documentation bug is what I have my money on.

No worries, I already fixed the issue using a MobileList and did the same to the others just in case. Many thanks though, but perhaps we need a point of clarification and perhaps a modification to the document.

Thanks!