How to check jquery already loaded or not?can we replace older version with new version programmatically?

Question

I want to know that when i add jquery in page i want to check before i add that does that jquery already added or not if not added then only add else not.

for example i have added jquery jquery-1.4.1.min

<script type="text/javascript" src="<?php echo SITE_JS;?>jquery-1.4.1.min"></script>

after that when i am trying to add jquery jquery-1.7.1.min

in case i didnt know that i have already added or not so i tried to add it but before that i want to check the version if the jquery with the old version or same then i dont want it to add else add new jquery and disable older one.

<script type="text/javascript" src="<?php echo SITE_JS;?>jquery-1.7.1.min"></script>

before adding this i want to check does jquery already exist with higher version or not. how is it possible?

window.jQuery but not just global variable jQuery which if undefined returns error — A. Wolff, May 30 '13 at 11:10
You're solving dependency issues in the wrong way. This isn't a code problem, it's a dependency problem. Fix the root cause, not just the symptoms. — Cory Danielson, Jan 17 '14 at 19:38

score 10 · Answer 1 · answered May 30 '13 at 11:10

10

Try it like,

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script>
    window.jQuery || document.write('<script src="<?php echo SITE_JS;?>/jquery-1.9.1.min.js"><\/script>');
 // you should have jquery-1.9.1.min.js on the site url
</script>

answered May 30 '13 at 11:10

Rohan Kumar

40,431
11
76
106

nice answer +1 fr this and in this case.. how to check higher version – Yadav Chetan May 30 '13 at 11:19
@RohanKumar how can i disable previous version of jquery that already loaded – Yadav Chetan May 30 '13 at 11:42
1

Look at this for your problem http://stackoverflow.com/questions/10915263/how-to-include-the-latest-jquery-file-without-affecting-old-plugins-in-drupal – Rohan Kumar May 30 '13 at 11:49

score 3 · Answer 2 · answered May 30 '13 at 11:12

try this method to check if jquery is loaded or not...if loaded print the version...

if (typeof jQuery != 'undefined') {  
        // jQuery is loaded => print the version
          alert(jQuery.fn.jquery);}

based on the version write a logic to load your version of jquery...

score 3 · Answer 3 · edited May 23 '17 at 10:34

3

use "window.load" event

(function() {
if (window.addEventListener) {
    // Standard
    window.addEventListener('load', jQueryCheck, false);
}
else if (window.attachEvent) {
    // Microsoft
    window.attachEvent('onload', jQueryCheck);
}
function jQueryCheck() {
    if (typeof jQuery === "undefined") {
        // No one's loaded it; either load it or do without
    }
}
})();

Ref

edited May 23 '17 at 10:34

Community

1
1

answered May 30 '13 at 11:12

Mayank Awasthi

337
3
14

How to check jquery already loaded or not?can we replace older version with new version programmatically?

3 Answers3