Using jQuery from Google CDN doesn't work

Question

I used drupal 6.22 and I enabled the jQuery Update and jQuery UI modules; I used the latest version (JQuery 1.6.4 and 1.8.16) in my libraries. When I added this code in template.php (my theme) all the page worked correctly in my web site.

drupal_add_js('sites/all/libraries/jqgrid/js/jquery.js');
drupal_add_js('sites/all/libraries/jqgrid/js/jquery-ui-custom.min.js');

When I decided to use a content delivery network (CDN) some of the pages don't work correctly.

drupal_set_html_head('<script type=text/javascript src="https://www.google.com/jsapi?key=my site"></script>'); 
drupal_add_js('google.load("jquery", "1.6.4"); google.load("jqueryui", "1.8.16");'

Why is this happening?

If I use the following code, some of the pages still don't work correctly.

drupal_set_html_head('<script type=text/javascript src="https://www.google.com/jsapi?key=my site"></script>'); 
drupal_add_js('google.load("jquery", "1.6.4"); google.load("jqueryui", "1.8.16");

Answer 1

In Drupal 6, you cannot use drupal_add_js to add external JS files. You need to use drupal_set_html_head. Thankfully, in D7 this has been fixed.

drupal_set_html_head('<script type="javascript" src="https://www.google.com/jsapi?key=my site"></script>');
drupal_add_js('google.load("jquery", "1.6.4"); google.load("jqueryui", "1.8.16");', 'inline');

Answer 2

Adding the markup to load a more recent version of jQuery from a CDN is not a good solution, it won't prevent the older version from being loaded. You will eventually run into issues when the wrong version of jQuery is used by a script expecting the other. The proper solution is to alter the path the jQuery (and jQuery UI) files before outputting the <script> markup as the jQuery update module does.

The Advanced CSS/JS Aggregation is probably an easier solution as it claims to be able to load jQuery and jQuery UI from CDNs.

Note that the Drupal 6 version of jQuery update only provides jQuery1.3.2 because some Drupal core's JavaScript scripts are not compatible with more recent versions of jQuery. For the same reason the Drupal 7 versions currently stops at jQuery 1.5.2 and jQuery UI 1.8.11. If you use more recent versions, you will eventually runs into incompatibility issues.

Answer 3

The jQuery CDN module upgrades Drupal's internal version of jQuery with one hosted on an external CDN.

Answer 4

The AdvAgg sub module "AdvAgg CDN Javascript" will use Google's CDN for jQuery & jQuery UI. Be sure to change version.txt in jquery_ui to the version you want to use & set the advagg_js_cdn_jquery_update_version variable to 1.6.4

Answer 5

If you are using Drupal 7 then you can add an external js file using drupal_add_js():

drupal_add_js('http://example.com/example.js', 'external');