Case 7 :
Web Developer declared only footer in page
but need to add back button dynamically
select footer and call barlayout("addBackBtn") API
<div data-role="page" data-add-back-btn="none">
<div data-role="header" data-position="fixed">
<h1>back button sample</h1>
</div>
<div data-role="content">
</div>
<div data-role="footer">
</div>
</div>
<script>
var $elFooter = $(".ui-page-active").find(".ui-footer");
$elFooter.barlayout("addBackBtn");
</script>