How to force a script reload and re-execute?

Question

I have a page that is loading a script from a third party (news feed). The src url for the script is assigned dynamically on load up (per third party code).

<div id="div1287">
    <!-- dynamically-generated elements will go here. -->
</div>

<script id="script0348710783" type="javascript/text">
</script>

<script type="javascript/text">
    document.getElementById('script0348710783').src='http://oneBigHairyURL';
</script>

The script loaded from http://oneBigHairyURL then creates and loads elements with the various stuff from the news feed, with pretty formatting, etc. into div1287 (the Id "div1287" is passed in http://oneBigHairyURL so the script knows where to load the content).

The only problem is, it only loads it once. I'd like it to reload (and thus display new content) every n seconds.

So, I thought I'd try this:

<div id="div1287">
    <!-- dynamically-generated elements will go here. -->
</div>

<script id="script0348710783" type="javascript/text">
</script>

<script type="javascript/text">
    loadItUp=function() {
        alert('loading...');
        var divElement = document.getElementById('div1287');
        var scrElement = document.getElementById('script0348710783');

        divElement.innerHTML='';
        scrElement.innerHTML='';
        scrElement.src='';
        scrElement.src='http://oneBigHairyURL';
        setTimeout(loadItUp, 10000);
    };
    loadItUp();
</script>

I get the alert, the div clears, but no dynamically-generated HTML is reloaded to it.

Any idea what I'm doing wrong?

I don't know if the browser understands that you want it to download the js again, since you're trying to load the same url over and over. it probably sees it as the same and doesn't bother. try a caching technique when you change the src: `scrElement.src='http://oneBigHairyURL?v=2'; //auto-increment this value` — Matt K, Mar 09 '12 at 23:22
@Matt K. Yes, I should have posted that I've tried this, but to no avail. Sorry it wasn't part of the original post. — Jonathan M, Mar 12 '12 at 19:51
@JonathanM I'm stuck at the same thing, did you find a solution? Adding version doesn't work. — Parth, Oct 02 '15 at 06:38
@JonathanM that by generating new script tag, it does work. How about loading the same tag but just changing the value of 'src' attribute? — Parth, Oct 02 '15 at 15:05
@Dr..Net, the selected answer was the only thing I got to work. Tried changing `src` to no avail. To trim down the DOM, I remove old ` — Jonathan M, Oct 02 '15 at 16:44
I´ve also a reload/refresh problem, may you can help me by fix it? https://stackoverflow.com/a/48916962/9392215 — Daniel Stappenbeck, Feb 21 '18 at 23:23

score 91 · Accepted Answer · edited May 08 '18 at 11:12

91

How about adding a new script tag to <head> with the script to (re)load? Something like below:

<script>
   function load_js()
   {
      var head= document.getElementsByTagName('head')[0];
      var script= document.createElement('script');
      script.src= 'source_file.js';
      head.appendChild(script);
   }
   load_js();
</script>

The main point is inserting a new script tag -- you can remove the old one without consequence. You may need to add a timestamp to the query string if you have caching issues.

edited May 08 '18 at 11:12

Chuck Le Butt

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answered Mar 09 '12 at 23:30

Kelly

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For cache problems, the best thing is to add a timestamp to the url `'hello.js?cachebuster='+ new Date().getTime() ` – Juan Mendes Mar 09 '12 at 23:36
@Juan Mendes, thats correct because a news feed has to be loaded again. Skip it only when cache is wanted in case only rerun is needed and a new unnessecary load would be a slow down, for example a script that doesnt change. – Aug 04 '19 at 21:54

score 44 · Answer 2 · answered May 15 '13 at 19:42

44

Here's a method which is similar to Kelly's but will remove any pre-existing script with the same source, and uses jQuery.

<script>
    function reload_js(src) {
        $('script[src="' + src + '"]').remove();
        $('<script>').attr('src', src).appendTo('head');
    }
    reload_js('source_file.js');
</script>

Note that the 'type' attribute is no longer needed for scripts as of HTML5. (http://www.w3.org/html/wg/drafts/html/master/scripting-1.html#the-script-element)

answered May 15 '13 at 19:42

Luke

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Great!! It helps me a lot after a lot of searching. Thanks. – Md. Salahuddin Oct 30 '14 at 11:35
4

You can add new JS, but you can't get rid of the old. Any listeners, etc. from the original script will still be live even if you remove its script tag. – user984003 Aug 23 '16 at 12:09

Juan Mendes · Answer 3 · 2022-05-19T19:38:18.317

Creating a new script tag and copying the contents of the existing script tag, and then adding it, works well.

var scriptTag = document.createElement('script');
scriptTag.innerText = "document.body.innerHTML += 'Here again ---<BR>';";
var head = document.getElementsByTagName('head')[0];
head.appendChild(scriptTag);

setInterval(function() {
    head.removeChild(scriptTag);
    var newScriptTag = document.createElement('script');
    newScriptTag.innerText = scriptTag.innerText;
    head.appendChild(newScriptTag);
    scriptTag = newScriptTag;    
}, 1000);

This won't work if you expect the script to change every time, which I believe is your case. You should follow Kelly's suggestion, just remove the old script tag (just to keep the DOM slim, it won't affect the outcome) and reinsert a new script tag with the same src, plus a cachebuster.

score 7 · Answer 4 · edited Jun 10 '19 at 09:29

7

Small tweak to Luke's answer,

 function reloadJs(src) {
    src = $('script[src$="' + src + '"]').attr("src");
    $('script[src$="' + src + '"]').remove();
    $('<script/>').attr('src', src).appendTo('head');
}

and call it like,

reloadJs("myFile.js");

This will not have any path related issues.

edited Jun 10 '19 at 09:29

fugu

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answered Sep 14 '15 at 16:44

Maleen Abewardana

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Shouldn't it `.appendTo('head')` instead of the body? – Jonathan M Mar 23 '16 at 23:06
@JonathanM We normally keep our script at the end of the body. When I was posting this, this worked for me. I think you can also append to head, if needed. – Maleen Abewardana Mar 24 '16 at 15:25
1

This is the one – Jun 13 '19 at 15:37

score 6 · Answer 5 · answered Nov 06 '18 at 00:30

Use this function to find all script elements containing some word and refresh them.

function forceReloadJS(srcUrlContains) {
  $.each($('script:empty[src*="' + srcUrlContains + '"]'), function(index, el) {
    var oldSrc = $(el).attr('src');
    var t = +new Date();
    var newSrc = oldSrc + '?' + t;

    console.log(oldSrc, ' to ', newSrc);

    $(el).remove();
    $('<script/>').attr('src', newSrc).appendTo('head');
  });
}

forceReloadJS('/libs/');

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>

score -2 · Answer 6 · answered Dec 08 '19 at 10:00

I know that is to late, but I want to share my answer. What I did it's save de script's tags in a HTML file, locking up the scripts on my Index file in a div with an id, something like this.

<div id="ScriptsReload"><script src="js/script.js"></script></div>

and when I wanted to refresh I just used.

$("#ScriptsReload").load("html_with_scripts_tags.html", "", function(
    response,
    status,
    request
  ) {

  });

How to force a script reload and re-execute?

6 Answers6

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