How to include multiple js files using jQuery $.getScript() method

user_1413598 0
Viewed 136013

I am trying to dynamically include javascript files into my js file. I did some research about it and find jQuery $.getScript() method would be a desired way to go.

// jQuery
$.getScript('/path/to/imported/script.js', function()
{
    // script is now loaded and executed.
    // put your dependent JS here.
    // what if the JS code is dependent on multiple JS files? 
});

But I am wondering whether this method can load multiple scripts at one time? Why I am asking this is because sometimes my javascript file is depending on more than one js files.

Thank you in advance.

promise html jquery javascript
19 Answers

Here is answer using Maciej Sawicki's one and implementing Promise as callback:

function loadScripts(urls, path) {
    return new Promise(function(resolve) {
        urls.forEach(function(src, i) {

            let script = document.createElement('script');        
            script.type = 'text/javascript';
            script.src = (path || "") + src;
            script.async = false;

            // If last script, bind the callback event to resolve
            if(i == urls.length-1) {                    
                // Multiple binding for browser compatibility
                script.onreadystatechange = resolve;
                script.onload = resolve;
            }

            // Fire the loading
            document.body.appendChild(script);
        });
    });
}

Use:

let JSDependencies = ["jquery.js",
                      "LibraryNeedingJquery.js",
                      "ParametersNeedingLibrary.js"];

loadScripts(JSDependencies,'JavaScript/').then(taskNeedingParameters);

All Javascript files are downloaded as soon as possible and executed in the given order. Then taskNeedingParameters is called.

user_87901020

You can give this a try using recursion. This will download them in sync, one after another until it completes downloading the whole list.

var queue = ['url/links/go/here'];

ProcessScripts(function() { // All done do what ever you want

}, 0);

function ProcessScripts(cb, index) {
    getScript(queue[index], function() {
        index++;
        if (index === queue.length) { // Reached the end
            cb();
        } else {
            return ProcessScripts(cb, index);
        }
    });
}

function getScript(script, callback) {
    $.getScript(script, function() {
        callback();
    });
}
user_18274240

I have improved @adeneo script so it will load all scripts in the specified order. It doesn't do chain loading, so it's very fast, but if you want even faster, change the 50 ms wait time.

$.getMultiScripts = function(arr, path) {

    function executeInOrder(scr, code, resolve) {
        // if its the first script that should be executed
        if (scr == arr[0]) {
            arr.shift();
            eval(code);
            resolve();
            console.log('executed', scr);
        } else {
            // waiting
            setTimeout(function(){
                executeInOrder(scr, code, resolve);
            }, 50);
        }
    }

    var _arr = $.map(arr, function(scr) {

        return new Promise((resolve) => {
            jQuery.ajax({
                type: "GET",
                url: (path || '') + scr,
                dataType: "text",
                success: function(code) {
                    console.log('loaded  ', scr);
                    executeInOrder(scr, code, resolve);
                },
                cache: true
            });
        });

    });
        
    _arr.push($.Deferred(function( deferred ){
        $( deferred.resolve );
    }));
        
    return $.when.apply($, _arr);
}

Usage is the same:

var script_arr = [
    'myscript1.js', 
    'myscript2.js', 
    'myscript3.js'
];

$.getMultiScripts(script_arr, '/mypath/').done(function() {
    // all scripts loaded
});
user_26996670
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