dynamically linking to ajax.googleapis jquery

Hi
    I am using jquery and jqueryui in my application And in layout I use

<%= javascript_include_tag
"http://ajax.googleapis.com/ajax/libs/jquery/1.4.1/jquery.min.js"%>
<%= javascript_include_tag
"http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js" %>
<%= stylesheet_link_tag
"http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/redmond/jquery-ui.css"
%>

        My question is, there any problem by linking to css and js like
these. I am totally a newbie regarding this? Is this a performance issue
in production. And I have one more concern(Dont know I am right) suppose
if in any case those sights down then will it fail? What is the normal
procedure for doing this? Whether I have to download all the sources to
my application?

Thanks for your time
Tom

"Tom Mac" <lists@ruby-forum.com> wrote in message news:19b735ce38b38e739aa3674645d85cce@ruby-forum.com...

Hi
   I am using jquery and jqueryui in my application And in layout I use

<%= javascript_include_tag
"http://ajax.googleapis.com/ajax/libs/jquery/1.4.1/jquery.min.js"%>
<%= javascript_include_tag
"http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js" %>
<%= stylesheet_link_tag
"http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/redmond/jquery-ui.css"
%>

       My question is, there any problem by linking to css and js like
these. I am totally a newbie regarding this? Is this a performance issue
in production. And I have one more concern(Dont know I am right) suppose
if in any case those sights down then will it fail? What is the normal
procedure for doing this? Whether I have to download all the sources to
my application?

If Google is down (yes, it does happen on rare occasion!) the javascript files will fail to load. Any code that tries to use jquery would fail. In the best case, all remaining code will continue to work, and thus only some small part of the site will be broken. In the worst case, the browser will give up on running javascript for the page, and the page wil continue to work like javascript was not enabled. If your site is designed well it will work even when javascript is not enabled, but some non-essential fancy AJAX'y stuff might not work.

It is pretty easy to test out what would happen if they fail to load simply by changing the "/ajax/" part of each url to "/noajax/", which of course does not exist and will cause the downloads to fail. Just be sure to change them back when done testing.

As for performance, remote loading from Google may sometimes be faster or other times slower than storing the file on the server. You can get more consistant perforance by putting the files on your server, but more consistant might not be better.

Many people err on the side of caution and choose to keep local copies of jquery.min.js, jquery-ui.min.js and jquery-ui.css on their servers. If in doubt, I'd suggest that. It is easy to download the files and place them in public/javascripts and public/stylesheets.

Hi Joe

   Thanks for your elaborate answer. It was useful

Tom