How to get email from identityref

Question

I've looked at the UserHttpClient, ProfileHttpClient and GraphHttpClient.

I cannot figure out how I can retrieve the email address from any of those when I have an IdentityRef from a work item (the "AssignedTo" field).

Earlier I assumed that the uniquename field always where the email address, but that seems not to be the case for premise installations?

Answer 1

I finally figured it out.

The identityRef contains a field called Descriptor which corresponds to the "user descriptor" in the ProfileHttpClient (Rest api).

Thus, to get the email one have to do the following:

public static Task<string> GetEmailAddress(this VssConnection connection, SubjectDescriptor descriptor)
{
    var client = connection.GetClient<GraphHttpClient>();
    var user = await client.GetUserAsync(descriptor.ToString());
    return user?.MailAddress;
}

// .. and in your code (where assignedTo is an IdentityRef).
var email = await connection.GetEmailAddress(assignedTo.Descriptor);

Update

This doesn't work on Azure DevOps Server as the Graph is not available on it. So the question remains.

(Leaves this as an answer for the cloud version)