C# MsGraph-SDK: Send a BatchRequest to get manager links using Microsoft Graph SDK - microsoft-graph-api

Question

First of all please share if there is any MSGraph SDK official documentation anywhere that I can use for reference.
I have a scenario, where I want to query all manager and member links from AAD without providing the user and group objectID respectively. This is currently supported in DQ channel, i.e. I can do something like this using MsGraphSDK:
MsGraphClient.Users.Delta().Request().Select("manager")
OR
MsGraphClient.Groups.Delta().Request().Select("members")
I don't want to use DQ for initial-sync due to performance problems, and other issues.
My fallback option is to query through Graph directly, so I want to do something like the following, but this doesn't return any result:
MsGraphClient.Users.Request().Select("manager")
OR
MsGraphClient.Groups.Request().Select("members")
It looks like this isn't even supported currently at the lower (AADGraph) layer. Please correct me if I am wrong, and provide a solution if any!
So my fallback approach is to pull all the user and group aadObjectIds, and explicitly query the manager and member links respectively.
In my case, there can potentially be 500K User-Objects in AAD, and I want to avoid making 500K separate GetManager calls to AAD. Instead, I want to batch the Graph requests as much as possible.
I wasn't able to find much help from the Internet on sending Batch requests through SDK.
Here's what I am doing:
I have this BatchRequestContent:
var batchRequestContent = new BatchRequestContent();
foreach (string aadObjectId in aadObjectIds)
{
batchRequestContent.AddBatchRequestStep(new BatchRequestStep(aadObjectId, Client.Users[aadObjectId].Manager.Request().GetHttpRequestMessage()));
}
and I am trying to send a BatchRequest through GraphSDK with this content to get a BatchResponse. Is this currently supported in SDK? If yes, then what's the procedure? Any documentation or example? How to read the batch-response back? Finally, is there any limit for the # of requests in a batch?
Thanks,

Answer 1

Here is a related post: $expand=manager does not expand manager
$expand is currently not supported on the manager and directReports relationships in the v1.0 endpoint. It is support in the beta endpoint but
the API returns way to much throw away information: https://graph.microsoft.com/beta/users?$expand=manager
The client library partially supports Batch at this time although we have a couple of pull requests to provide better support
with the next release (PR 1 and 2).
To use batch with the current library and your authenticated client, you'll do something like this:
var authProv = MsGraphClient.AuthenticationProvider;
var httpClient = GraphClientFactory.Create(authProv);
// Send batch request with BatchRequestContent.
HttpResponseMessage response = await httpClient.PostAsync("https://graph.microsoft.com/v1.0/$batch", batchRequestContent);
// Handle http responses using BatchResponseContent.
BatchResponseContent batchResponseContent = new BatchResponseContent(response);