Pulling user/group field data from SharePoint list using REST, jQuery, Knockout.js Sharepoint 2013

Question

I'm trying to make an interactive task board based on the task list app in SharePoint 2013. The task lisk includes fields like "Title","Description","Status","% Complete","Due Date","Assigned To",
etc. I used knockout.js to bind "Title","Description", and "Status" to my HTML controls. Here is some of the code:
var ViewModal = function(items, listname){
var self = this;
self.sortBy = ko.observableArray(sortBy);
self.tasks = ko.observableArray(items);
self.listname = ko.observable(listname);
self.auto = ko.observable(false);
self.getTasks = function() {
clearTimeout(self.getTasks);
// server relative url to REST service endpoint
var ajaxurl = _spPageContextInfo.webServerRelativeUrl + "/_vti_bin/listdata.svc/" + self.listname() + "?$orderby=PriorityValue";
$.ajax({
type: "GET",
url: ajaxurl,
contentType: "application/json; charset=utf-8",
dataType: "json",
cache: false,
processData: true,
success: function (data, status, xhr) {
if (status == "success" && data) {
ko.mapping.fromJS(data.d.results, mapping, self.tasks)
$(".task-item").draggable();
error: alert
if (self.auto()) {
setTimeout(self.getTasks, 10000);
<div class="tasks-column">
<div class="column-header">Not Started</div>
<!-- ko foreach: tasksNotStarted -->
<div class="task-item">
<div class="view" data-bind="visible: !IsEditing()">
<button class="edit" data-bind="click: $root.editTask">edit</button>
<h2><span data-bind="text: Title"></span></h2>
<div data-bind="html: Description"></div>
<span data-bind="text: PriorityValue"></span>
</div>
<div class="edit" data-bind="visible: IsEditing">
<button class="save" data-bind="click: $root.saveTask">save</button>
<input type="text" data-bind="value: Title"></input>
</div>
</div>
I'm having trouble displaying the data from the "Assigned To" user/group field. I tried:
<span data-bind="text: AssignedTo"></span>
But it displays the field as [object Object]
I tried using $select/$expand
?$select=Title,AssignedTo/Id,Assignedto/Title&$expand=AssignedTo/Id,AssignedTo/T‌​itle";
But it still returns the [object Object]

Answer 1

Hi,
Please use the REST URI below:
/_api/lists/getbytitle('ListName')/items?$select=Title,AssignedTo/ID,AssignedTo/Title&$expand=AssignedTo/ID,AssignedTo/Title
More information for your reference:
How to get User Details and User Group Details in SharePoint 2013 REST API with Knockout for SharePoint Js (KoSpJs)
http://www.ashokraja.me/post/How-to-get-User-Details-and-User-Group-Details-in-SharePoint-2013-REST-API-with-Knockout-for-SharePoint-Js-(KoSpJs).aspx
How to Get Login Name and Display Name using SharePoint 2013 REST API
https://www.nothingbutsharepoint.com/sites/devwiki/articles/pages/how-to-get-login-name-and-display-name-using-sharepoint-2013-rest-api.aspx
Best Regards
Dennis Guo
TechNet Community Support