Get User via JavaScript Client Object Model

Question

Is there a way to get user information via the JavaScript Client OM? Something similar to the clientContext.Web.EnsureUser(userName) method. I am aware that there is the SPService JQuery library, but if I can do this via the Client Object Model, I would prefer that. And just to be clear: I am NOT talking about the current logged in user. I want to verify the existence of a user in a manner similar to the people picker control.

Edit: Here is some example code... It assumes JQuery is loaded. Just plug it into an HTML Form webpart.

<input type="text" id="user-name">&nbsp;<input type="button" id="myButton" value="check name" />
<script type="text/javascript">
   $(document).ready($('#myButton').click(function(){
     verifyUser($('#user-name').val());
    }));

    function verifyUser(userName){
       var context = new SP.ClientContext.get_current(); 
       var web = context.get_web();
       var user = web.ensureUser(userName);
       context.load(user); 

       context.executeQueryAsync( 
           function(sender, args) {showUserData(user);}, 
           function(sender, args) {alert("Error: " + args.get_message());} 
    );
    }
    function showUserData(user){
        $('#display-user-info').html('<tr><td>Name: '+user.get_title()+'</td><td>&nbsp;Email: '+user.get_email()+'</td></tr>'
        );
        $('#user-name').val(user.get_title());
    }
</script>
<table id="display-user-info">
</table>

Answer 1

There is an ensureUser Method in the JS Client Object Model:

http://msdn.microsoft.com/en-us/library/ff408786.aspx

Answer 2

How to retrieve UserInfo by UserName from UserInfo List via CSOM

function getUserInfo(userName,Success,Error)
{
   var context = new SP.ClientContext.get_current();
   var userInfoList = context.get_web().get_siteUserInfoList();
   var query = new SP.CamlQuery();
   var viewXml = "<View> \
                    <Query> \
                       <Where> \
                           <Eq><FieldRef Name='UserName' /><Value Type='Text'>" + userName + "</Value></Eq> \
                       </Where>  \
                    </Query> \
                    <RowLimit>1</RowLimit> \
                  </View>";
   query.set_viewXml(viewXml);
   var items = userInfoList.getItems(query);
   context.load(items,'Include(Deleted,Department,EMail,FirstName,ID,IsActive,IsSiteAdmin,JobTitle,LastName,MobilePhone,Name,Notes,Office,Picture,SipAddress,UserName,WebSite,WorkPhone)');
   context.executeQueryAsync(function(){
       if(items.get_count() > 0) {
          var item = items.itemAt(0);
          Success(item.get_fieldValues());
       }
       else {
          Success(null);
       }   
     },
     Error
   );
}




//Usage
getUserInfo('[email protected]',function(userInfo){
       console.log('User Id: ' + userInfo.ID);
    },
    function(sender,args){
       console.log(args.get_message());
});    

Answer 3

You could build a function using the SP.Web.siteUserInfoList.

And here is a link to an example

I'm not aware of a method like EnsureUser, there is a UserCollection with some methods for retrieving users, but looks like you have to get a site group first.