Delay for localstorage to finished loading?

Hi, I’m trying to pass data through localstorage to next page and planning to use preloader to show around 2 second before webix.ui start. My problem now (what I think) is that the page load faster that localstorage and end up error because the data is null but if i refresh the page then all data will show correctly. Is my assumption correct? and what can I do with it. Thanks
(I’m new to these things so I’m not sure if webix have this cover or I have to do it using javascript and what I found is the settimeout which have to use in function and I dont know how to apply that to webix.ready/web.ui)