How to get users from SharePoint through CSOM?

Question

How can I effectively capture users (with my properties) from a SharePoint website using CSOM? The code below leads to several server calls (one for each user). It is ridiculously inefficient.

Also, is it possible to filter on the server?

    public static List<Contact> GetUsers(Uri requestUri, string Filter = "")
    {
        ClientContext context;
        var users = new List<Contact>();
        if (ClientContextUtilities.TryResolveClientContext(requestUri, out context, null))
        {
            using (context)
            {
                var web = context.Web;
                var peopleManager = new PeopleManager(context);

                context.Load(web, w => w.Title, w => w.Description, w => w.SiteUsers);
                var siteUsers = web.SiteUsers;
                context.ExecuteQuery();

                foreach (var user in siteUsers)
                    if (user.PrincipalType == Microsoft.SharePoint.Client.Utilities.PrincipalType.User)
                        if (user.Title.ToLower().Contains(Filter.ToLower()) && !users.Any(x => x.FullName == user.Title))
                        {
                            var userProfile = peopleManager.GetPropertiesFor(user.LoginName);
                            context.Load(userProfile);
                            context.ExecuteQuery();

                            var contact = new Contact() { FullName = user.Title, EmailAddress = user.Email };
                            if (userProfile.IsPropertyAvailable("Title"))
                                contact.Position = userProfile.Title;
                            if (userProfile.IsPropertyAvailable("UserProfileProperties") && userProfile.UserProfileProperties.ContainsKey("WorkPhone"))
                                contact.PhoneNumber = userProfile.UserProfileProperties["WorkPhone"];
                            users.Add(contact);
                        }
            }
        }
        return users;
    }

Answer 1

Major Improvements

Since SharePoint CSOM supports Request Batching , all user profiles can be obtained using a single request, for example, instead of:

foreach (var user in siteUsers)
{
   var userProfile = peopleManager.GetPropertiesFor(user.LoginName);
   context.Load(userProfile);
   context.ExecuteQuery();
}

User profiles can be obtained as:

var userProfilesResult = new List<PersonProperties>(); //for storing user profiles
foreach (var user in siteUsers)
{
   var userProfile = peopleManager.GetPropertiesFor(user.LoginName);
   context.Load(userProfile);
   userProfilesResult.Add(userProfile);
}
context.ExecuteQuery();  //submit a single request 

Minor improvements

1) SharePoint CSOM CAML, , :

var siteUsers = from user in web.SiteUsers
                    where user.PrincipalType == Microsoft.SharePoint.Client.Utilities.PrincipalType.User
                    select user;
var usersResult = context.LoadQuery(siteUsers);
context.ExecuteQuery();

2) , , :

var hasUserProfile = userProfile.ServerObjectIsNull != null && userProfile.ServerObjectIsNull.Value != true;

public static List<Contact> GetUsers(Uri requestUri, ICredentials credentials, string filter = "")
{
        ClientContext context;
        var users = new List<Contact>();
        if (ClientContextUtilities.TryResolveClientContext(requestUri, out context, credentials))
        {
            var userProfilesResult = new List<PersonProperties>();
            using (context)
            {
                var web = context.Web;
                var peopleManager = new PeopleManager(context);


                var siteUsers = from user in web.SiteUsers
                    where user.PrincipalType == Microsoft.SharePoint.Client.Utilities.PrincipalType.User
                    select user;
                var usersResult = context.LoadQuery(siteUsers);
                context.ExecuteQuery();

                foreach (var user in usersResult)
                {
                    if (user.Title.ToLower().Contains(filter.ToLower()) && !users.Any(x => x.FullName == user.Title))
                    {
                        var userProfile = peopleManager.GetPropertiesFor(user.LoginName);
                        context.Load(userProfile);
                        userProfilesResult.Add(userProfile);
                    }
                }
                context.ExecuteQuery();


                var result = from userProfile in userProfilesResult 
                             where userProfile.ServerObjectIsNull != null && userProfile.ServerObjectIsNull.Value != true
                        select new Contact() {
                            FullName = userProfile.Title,
                            EmailAddress = userProfile.Email,
                            Position = userProfile.IsPropertyAvailable("Title") ? userProfile.Title : string.Empty,
                            PhoneNumber = userProfile.IsPropertyAvailable("UserProfileProperties") && userProfile.UserProfileProperties.ContainsKey("WorkPhone") ? userProfile.UserProfileProperties["WorkPhone"] : string.Empty
                        };
                users = result.ToList();
            }
        }
        return users;
 }

Answer 2

-, :

using (var ctx = new ClientContext("http://theWebsite"))
{
    var list = ctx.Web.SiteUserInfoList;
    var users = list.GetItems(new CamlQuery());
    ctx.Load(users);
    ctx.ExecuteQuery();

    // do what you want with the users
}