04-13-2014 10:22 PM - last edited on 08-14-2016 10:38 AM by kathleen_jo
Flicker is typically removed by using synchronous scripting or creating A/B tests that do not replace default content on the page (this can be done async.) Synchronous scripting on web pages in general is not considered a best practice. I would recommend an asynchronous approach. For a very high-performance asynchronous implementation, I would recommend:
(1) Use the "Bundling" feature in Publish Settings
(2) Code your utag.js at the top of the HTML source (Tealium Code Center recommends top of body as the best practice.)
(3) Set your tag to "Wait = No" (in Advanced Settings for your Tag config)
(4) Use the latest utag.js (version 4.2x or later)
(5) Move your Visual Website Optimizer to the top of the list in the "Tags" tab so it will run first If you are willing to take on the risks of a synchronous Visual Website Optimizer tag, Tealium provides the option to use a "utag.sync.js" template. This is enabled in Publish Settings as well.
With the utag.sync.js in place (implemented synchronously in the "head" section of your HTML page) you can use document.write to insert a script block that will inject your Visual Website Optimizer script. The utag.sync.js is an editable Template where you can add synchronous JS code (document.write statements.) Again, be sure you understand the risks of using synchronous code and synchronous tag vendors on your site.