Script to Inject a jQuery loader using ScriptTags for Shopify

jquery-loader.js

(function () {
 
  function loadScript(url, callback) {
    var script = document.createElement("script")
    script.type = "text/javascript";

    if (script.readyState) { //IE
      script.onreadystatechange = function () {
        if (script.readyState == "loaded" || script.readyState == "complete") {
          script.onreadystatechange = null;
          callback();
        }
      };
    } else { //Others
      script.onload = function () {
        callback();
      };
    }

    script.src = url;
    document.getElementsByTagName("head")[0].appendChild(script);
  }

  if(typeof jQuery == undefined || typeof jQuery == "undefined"){
    loadScript("//ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js", function () {
      jQuery.noConflict();
      console.log('jquery loaded');
      //Code to run after jQuery is loaded
    });
  } else {
    //Code to run after jQuery is loaded
  }
})();

preloader.js

(function(){
  var dynamic_loader_tag = document.createElement("script");
  dynamic_loader_tag.src = "/path/to/jquery-loader.js";
  dynamic_loader_tag.type = "text/javascript";
  dynamic_loader_tag.async = true;

  document.getElementsByTagName('body')[0].appendChild(dynamic_loader_tag);
})();