I have a VF page containing lightning component using ltng out. It is taking time to load(about 6 seconds) , and in that time I want to show spinner to user. How can this be implemented? My VF Page: <apex:page > <script src="https://MySSDDomain-dev-dev-ed.my.salesforce.com/lightning/lightning.out.js" /> <apex:includeLightning /> <div id="lightning" /> <script> $Lightning.use("c:UserPageApplication", function() { $Lightning.createComponent("c:UserPageComponent", {}, "lightning", function(cmp) { //do something }); }); </script> </apex:page>