Adding a script to the page dynamically with jQuery never uses the cached file

Question

I am using jQuery to dynamically add a script to my page and it works, but jQuery appends \"_=TIMESTAMP\" to the URL causing the browser to never use the cache. With the fo

Answer 1

Here is something that works for me

// Backup the jquery ajax cache setting
var jQueryAjaxSettingsCache = jQuery.ajaxSettings.cache;

// Disable the ?_=TIMESTAMP addition
jQuery.ajaxSettings.cache = true;

// Do the cached script inserting ...
$("head").append('<script src="//ajax.googleapis.com/ajax/libs/jqueryui/1.8.15/jquery-ui.min.js"></scr' + 'ipt>');

// Restore the jquery ajax cache setting
jQuery.ajaxSettings.cache = jQueryAjaxSettingsCache;

Answer 2

To answer your original question, you see the timestamp appended because jQuery by default sets cache: false for script and jsonp calls which appends the timestamp to the URL.

To avoid the timestamp, you can do this:

$.ajaxPrefilter(function( options, originalOptions, jqXHR ) {
  if ( options.dataType == 'script' || originalOptions.dataType == 'script' ) {
      options.cache = true;
  }
});

This sets up a global prefilter for all $.ajax calls, including the ones made by jQuery while requesting the script.

We inspect the dataType to make sure we're not inadvertantly targetting other ajax calls and explicitly set cache to true. This will avoid the timestamp appending problem.

You can now use your original code and it'll pick it up from cache.

Answer 3

You can use $.ajax to get the script instead of appending script tag

$.ajax({
  url: "http://ajax.googleapis.com/ajax/libs/jquery/1.5/jquery.min.js",
  dataType: "script",
  cache: true,//This will decide whether to cache it or no so that it will not add the timestamp along with the request
  success: function(){}//In the success handler you can write your code which uses resources from this js file ensuring the script has loaded successfully before using it
});