REST Angular Display Lookup Field

Question

<div ng-app="SharePointAngApp" class="row">
   <div ng-controller="spCustomerController" class="span10">
      <ul ng-repeat="file in files">
        <li><a href="SiteDomainUrl{{file.ServerRelativeUrl}}">{{file.Title}}</a> Category: {{file.Category.Title}} {{file.Category.Order}}</li>
      </ul>
   </div>
</div>


<script>
   var myAngApp = angular.module('SharePointAngApp', ['ngSanitize']);
   myAngApp.controller('spCustomerController', function ($scope, $http) {
     $http({
       method: 'GET',
       url: _spPageContextInfo.webAbsoluteUrl + "/_api/web/lists/getbytitle('Footer')/RootFolder/Files?$select=Title,CategoryId,Category/Title,Category/Order&$expand=Category&$orderBy=Title",
       headers: { "Accept": "application/json;odata=verbose" }
     }).success(function (data, status, headers, config) {
       $scope.files = data.d.results;
     }).error(function (data, status, headers, config) {
       console.log("REST Query Error!");
     });
  });
</script>

Why won't the lookup results show?

I don't see my Category lookup field within the results.

Results:

/ListItemsAllFields

<?xml version="1.0" encoding="utf-8" ?> 
- <entry xml:base="https://portal-qa.connect.te.com/sites/ehs/_api/" xmlns="http://www.w3.org/2005/Atom" xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices" xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" xmlns:georss="http://www.georss.org/georss" xmlns:gml="http://www.opengis.net/gml" m:etag=""3"">

<id>Web/Lists(guid'39a77f47-1e46-4796-a75f-ba1a94446515')/Items(15)</id> 


<category  term="SP.Data.FooterItem" scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme" /> 
<link  rel="edit" href="Web/Lists(guid'39a77f47-1e46-4796-a75f-ba1a94446515')/Items(15)" /> 
<link  rel="http://schemas.microsoft.com/ado/2007/08/dataservices/related/FirstUniqueAncestorSecurableObject" type="application/atom+xml;type=entry" title="FirstUniqueAncestorSecurableObject" href="Web/Lists(guid'39a77f47-1e46-4796-a75f-ba1a94446515')/Items(15)/FirstUniqueAncestorSecurableObject" /> 
<link  rel="http://schemas.microsoft.com/ado/2007/08/dataservices/related/RoleAssignments" type="application/atom+xml;type=feed" title="RoleAssignments" href="Web/Lists(guid'39a77f47-1e46-4796-a75f-ba1a94446515')/Items(15)/RoleAssignments" /> 
<link  rel="http://schemas.microsoft.com/ado/2007/08/dataservices/related/AttachmentFiles" type="application/atom+xml;type=feed" title="AttachmentFiles" href="Web/Lists(guid'39a77f47-1e46-4796-a75f-ba1a94446515')/Items(15)/AttachmentFiles" /> 
<link  rel="http://schemas.microsoft.com/ado/2007/08/dataservices/related/ContentType" type="application/atom+xml;type=entry" title="ContentType" href="Web/Lists(guid'39a77f47-1e46-4796-a75f-ba1a94446515')/Items(15)/ContentType" /> 
<link  rel="http://schemas.microsoft.com/ado/2007/08/dataservices/related/FieldValuesAsHtml" type="application/atom+xml;type=entry" title="FieldValuesAsHtml" href="Web/Lists(guid'39a77f47-1e46-4796-a75f-ba1a94446515')/Items(15)/FieldValuesAsHtml" /> 
<link  rel="http://schemas.microsoft.com/ado/2007/08/dataservices/related/FieldValuesAsText" type="application/atom+xml;type=entry" title="FieldValuesAsText" href="Web/Lists(guid'39a77f47-1e46-4796-a75f-ba1a94446515')/Items(15)/FieldValuesAsText" /> 
<link  rel="http://schemas.microsoft.com/ado/2007/08/dataservices/related/FieldValuesForEdit" type="application/atom+xml;type=entry" title="FieldValuesForEdit" href="Web/Lists(guid'39a77f47-1e46-4796-a75f-ba1a94446515')/Items(15)/FieldValuesForEdit" /> 
<link  rel="http://schemas.microsoft.com/ado/2007/08/dataservices/related/File" type="application/atom+xml;type=entry" title="File" href="Web/Lists(guid'39a77f47-1e46-4796-a75f-ba1a94446515')/Items(15)/File" /> 
<link  rel="http://schemas.microsoft.com/ado/2007/08/dataservices/related/Folder" type="application/atom+xml;type=entry" title="Folder" href="Web/Lists(guid'39a77f47-1e46-4796-a75f-ba1a94446515')/Items(15)/Folder" /> 
<link  rel="http://schemas.microsoft.com/ado/2007/08/dataservices/related/ParentList" type="application/atom+xml;type=entry" title="ParentList" href="Web/Lists(guid'39a77f47-1e46-4796-a75f-ba1a94446515')/Items(15)/ParentList" /> 
<title  /> 
<updated>2016-10-11T20:10:06Z</updated> 
- <author>
    <name  /> 
  </author>
- <content type="application/xml">
  - <m:properties>
      <d:FileSystemObjectType m:type="Edm.Int32">0</d:FileSystemObjectType> 
      <d:Id m:type="Edm.Int32">15</d:Id>
      <d:ContentTypeId>0x01010086299210AA67E44FA7FA832663E1BE6B</d:ContentTypeId> 
      <d:Title>HP_ULS_1-26-15</d:Title> 
      <d:URL  m:null="true" /> 
      <d:CategoryId m:type="Edm.Int32">2</d:CategoryId> 
      <d:ID m:type="Edm.Int32">15</d:ID> 
      <d:Created m:type="Edm.DateTime">2016-10-07T16:14:27</d:Created> 
      <d:AuthorId m:type="Edm.Int32">1</d:AuthorId> 
      <d:Modified m:type="Edm.DateTime">2016-10-07T16:14:37</d:Modified> 
      <d:EditorId m:type="Edm.Int32">1</d:EditorId> 
      <d:OData__CopySource  m:null="true" /> 
      <d:CheckoutUserId  m:null="true" /> 
      <d:OData__UIVersionString>1.0</d:OData__UIVersionString> 
      <d:GUID m:type="Edm.Guid">d365a0c3-66fd-4b60-9e1b-7f61c570801c</d:GUID> 
    </m:properties>
  </content>
</entry>

Answer 1

Thank you @DylanCristy for the push in the right direction. I was missing the '$' before select in the query.

url: _spPageContextInfo.webAbsoluteUrl + "/_api/web/lists/getbytitle('Footer')/items?$select=Title,Category/Title,Category/Order,Category/Column,File/Name,File/ServerRelativeUrl,ContentType/Name$expand=Category/Title,Category/Order,Category/Column,File,ContentType/Name"&$orderby=Category/Column,Category/Order",