Dynamically loaded javascript executed twice

Question

OK, I've got a nasty situation where everything works fine in my custom written script loader except the fact the script being loaded is executed twice.

here is complete code:

window._appCommons=window._appCommons||{};
$.loadScr = function(path, name, exportParam){
  var df = $.Deferred();
  if (! $( ['script[data-mname="', name, '"]'].join('') ).length ) {
    window._appCommons[name] = {};
    this.get(path).done(function(data){
        for (var prop in exportParam) {
            window._appCommons[name][prop] = exportParam[prop];
        }
        var scr = ['<script data-mname="' , name , '">' , data, '<\/script>'].join('');
        $(document.getElementsByTagName('head')[0]).append( scr );
        setTimeout(function(){ df.resolve(); },16);
    });
  }
  return df;
}

$.loadScr('one.js', 'onejs', {'someKey':'someValue'}).done(function(){});

The loaded script - one.js only contain console.log('something...') statement and I get this twice.

I can confirm:

that script appending - .append( scr ); happened only once
that script is "physically" loaded only once (confirmed from network panel)

and still, the same one.js, loaded once, appended once is executed twice.

So, does anyone have an idea what's happening?

UPDATE

I can now confirm that script is executed immediately after ajax loading, no matter of being appended or not. That means pure loading of javascript file, simple like $.get('one.js') executes containing javascript code. I do not know if this should happen and is there workaround or not...

Miloš Đakonović · Accepted Answer · 2015-12-06 13:07:08Z

2

For sake of completeness I have to respond to my own question - it's jQuery.get() default settings to blame - there is dataType field, which, if not set explicitly, becomes subject to what's called Intelligent Guess - and in case of loading script jQuery actually bothers to recognize javascript code and execute it.

My problem was solved by changing this.get(path).done... to:

    this.ajax({
      url: path,
      dataType: 'text'
    })
    .done//...

which doesn't execute received code, as it should be at first place.

answered Dec 6, 2015 at 13:07

Miloš Đakonović

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Praveen Kumar Purushothaman · Accepted Answer · 2015-12-06 11:10:47Z

1

Can you try using this? Personally tested and used script:

function loadjscssfile (filename, filetype){
    if (filetype=="js") { //if filename is a external JavaScript file
        var fileref=document.createElement('script')
        fileref.setAttribute("type","text/javascript")
        fileref.setAttribute("src", filename)
    }
    else if (filetype=="css") { //if filename is an external CSS file
        var fileref=document.createElement("link")
        fileref.setAttribute("rel", "stylesheet")
        fileref.setAttribute("type", "text/css")
        fileref.setAttribute("href", filename)
    }
    if (typeof fileref!="undefined")
        document.getElementsByTagName("head")[0].appendChild(fileref)
}

loadjscssfile("myscript.js", "js") //dynamically load and add this .js file
loadjscssfile("javascript.php", "js") //dynamically load "javascript.php" as a JavaScript file
loadjscssfile("mystyle.css", "css") ////dynamically load and add this .css file

answered Dec 6, 2015 at 11:10

Praveen Kumar Purushothaman

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2 Comments

Miloš Đakonović Over a year ago

Thanks Praveen, I'll check it out, but I have to fix this.

AamirR Over a year ago

it works and the script executes once

AamirR · Accepted Answer · 2022-01-13 08:19:40Z

0

Replacing jQuery.append to native Node.appendChild fixed the issue in my case

document.head.appendChild(scriptEl);

answered Jan 13, 2022 at 8:19

AamirR

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