How to get user details using remote event receiver SharePoint?

Question

I m working on SharePoint Add-ins using remote event receiver. I have created an add-in for my SharePoint site to get log of item added, item updated and item deleted details. I am getting item id which provides detail about the item on which operation is performed. How can I get details of user who has modified the file?

Here is my code for item adding:

if (clientContext != null)
{
    //Get reference to the host web list with name Feedback
    var documentsList = 
    clientContext.Web.Lists.GetByTitle("DemoRemoteEventReceiverList");
    clientContext.Load(documentsList);
    clientContext.ExecuteQuery();
    string remoteUrl = 
    "https://myApp.azurewebsites.net/Services/RemoteEventReceiver.svc";
    //Create the remote event receiver definition
    EventReceiverDefinitionCreationInformation newEventReceiver = new 
    EventReceiverDefinitionCreationInformation()
    {
        EventType = EventReceiverType.ItemAdded,
        ReceiverAssembly = Assembly.GetExecutingAssembly().FullName,
        ReceiverName = "RemoteEventReceiver1",
        ReceiverClass = "RemoteEventReceiver1",
        ReceiverUrl = remoteUrl,
        SequenceNumber = 15001
    };
    //Add the remote event receiver to the host web list
    documentsList.EventReceivers.Add(newEventReceiver);
    clientContext.ExecuteQuery();
}

Answer 1

Try

using (ClientContext clientContext = TokenHelper.CreateRemoteEventReceiverClientContext(properties))
            {
                if (clientContext != null)
                {
                    var user = clientContext.Web.CurrentUser;
                    clientContext.Load(user);
                    clientContext.ExecuteQuery();