Using Tridion Core Services how to obtain Members of group in which Group memberships obtained from an external (LDAP) directory?

Question

My Idea is to get the list of users for particular project in Tridion Publication using Core Services. I tried to get it from GroupMembershipData. But unfortunatly it is not including Group memberships obtained from an external (LDAP) directory.

So I am trying to get the Group Id using below code. But I am getting Object Reference Null error in the following line :

GroupData group = (GroupData)_client.Read(id, new ReadOptions());             

I understood the ID which I am passing is not correct. Because GroupData is inheriting TrusteeData. So I can't assign the child to Parent. So please help me to get the Publication ID of Group Members and Users for specific project.

protected void UserProjectUserCheck_Click(object sender, EventArgs e)
{
    ICoreService _client = Utility.GetCoreServiceSettings();
    PublicationsFilterData filterData = new PublicationsFilterData();
    var publicationList = _client.GetSystemWideListXml(filterData);
    PopulateProjectSpecificUserList(publicationList);
}

private void PopulateProjectSpecificUserList(XElement publicationList)
{
    string PublicationID = "";
    XmlDocument xmlDoc = new XmlDocument();
    string results = string.Empty;
    IEnumerable<XElement> elementList = publicationList.Elements();
    foreach(XElement elem in elementList)
    {
        if (elem.Attribute("Title").Value.ToString().ToLower().Contains("polo") && elem.Attribute("Title").Value.ToString().Trim().StartsWith("05"))
        {
            PublicationID = elem.Attribute("ID").Value.ToString();
        }
    }
    ICoreService _client = Utility.GetCoreServiceSettings();
    PublicationData pub = (PublicationData)_client.Read(PublicationID, null);

    AccessControlListData t =  pub.AccessControlList;

    string id = string.Empty;       
    foreach(var usrGroups in t.AccessControlEntries)
    {
        id = usrGroups.Trustee.IdRef;
    }           

    GroupData group = (GroupData)_client.Read(id, new ReadOptions());

    var searchDn = ((DirectoryGroupMappingData)group.ClaimMappings.First()).SearchDN;
    var directoryServiceName = ((DirectoryGroupMappingData)group.ClaimMappings.FirstOrDefault()).DirectoryServiceName;
    var result = _client.GetListDirectoryServiceGroupMembers(directoryServiceName, searchDn);

    TridionItemList.DocumentContent = result.ToString();
    TridionItemList.TransformSource = Server.MapPath(@".\ProjectSpecificUserList.xslt"); 
}

Answer 1

The LDAP group memberships are not in Tridion, so why try to get them out of Tridion? You should query the LDAP server to get this information.

Of course, you'll also probably want to communicate with Tridion to get the information which is there.