CoreService GetList() behaving differently to GetListXml()

Question

I am trying to use GetList to return all the users in a group, as below:

client.GetList(id, new GroupMembersFilterData())

However, I get the exception

{"Unexpected list type: Tridion.ContentManager.Data.Security.GroupMembersFilterData."}

When I use

client.GetListXml(id, new GroupMembersFilterData())

It works! Can anyone explain?

Normally I would probably use Xml anyway, but as I was doing a quick POC I thought I would make it easier and use objects.

Answer 1

The Content Manager Core Service API Reference Guide shows ICoreService2011.GetList takes two parameters:

1. TCM URI (or WebDAV URL) as a string
2. a Tridion.ContentManager.Data.SubjectRelatedListFilterData filter

However, there's a remark that "Currently only OrganizationalItemAncestorsFilterData filter is supported."

The SubjectRelatedListFilterData (abstract) class's inheritance includes:

• BluePrintChainFilterData
• CategoryRelatedFilterData
• ClassifiedItemsFilterData
• DeletedReferencesFilterData
• ItemsFilterData
• KeywordRelatedFilterData
• OrganizationalItemAncestorsFilterData
• OrganizationalItemsFilterData
• PathToCategoryFilterData
• RepositoryRelatedFilterData
• TaxonomiesFilterData
• VersionsFilterData
• GroupMembersFilterData
• WhereUsedFilterData

Long list short, use GetListXml() for any filter that isn't an OrganizationalItemAncestorsFilterData for SDL Tridion 2011.

Update: in at least SDL Tridion 2013, you should be able to get back objects on most filters.

ICoreService2012.GetList's updated remark notes that just TaxonomiesOwlFilterData is not supported.