Dynamically load locale for moment.js

moment.loadLocale.js

;(function(){
    if(window.moment === void 0)
        return console.error("Moment.js must be loaded first");

    var cdnLink = 'https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.24.0/locale/';
    var loaded = new Set();

    var available = ['af','ar-dz','ar-kw','ar-ly','ar-ma','ar-sa','ar-tn','ar','az','be','bg','bm','bn','bo','br','bs','ca','cs','cv','cy','da','de-at','de-ch','de','dv','el','en-au','en-ca','en-gb','en-ie','en-il','en-nz','en-SG','eo','es-do','es-us','es','et','eu','fa','fi','fo','fr-ca','fr-ch','fr','fy','ga','gd','gl','gom-latn','gu','he','hi','hr','hu','hy-am','id','is','it-ch','it','ja','jv','ka','kk','km','kn','ko','ku','ky','lb','lo','lt','lv','me','mi','mk','ml','mn','mr','ms-my','ms','mt','my','nb','ne','nl-be','nl','nn','pa-in','pl','pt-br','pt','ro','ru','sd','se','si','sk','sl','sq','sr-cyrl','sr','ss','sv','sw','ta','te','tet','tg','th','tl-ph','tlh','tr','tzl','tzm-latn','tzm','ug-cn','uk','ur','uz-latn','uz','vi','x-pseudo','yo','zh-cn','zh-hk','zh-tw'];
    
    moment.loadLocale = function(locale, callback){
        if(locale.length > 10)
            return; // Unexpected input

        if(locale.indexOf('_') !== -1)
            locale = locale.split('_');
        else
            locale = locale.split('-');

        var found = false;
        for(var i=0, n=locale.length; i<n; i++){
            var temp = locale.join('-');
            if(available.indexOf(temp) !== -1){
                found = temp;
                break;
            }

            locale.pop();
        }

        if(found !== false){
            if(loaded.has(found)){
                moment.locale(found);
                return callback && callback(found);
            }

            var xhr = new XMLHttpRequest();
            xhr.open("GET", cdnLink+found+'.js');

            xhr.onreadystatechange = function(){
                if(xhr.status === 200 && xhr.readyState === 4){
                    this.moment = window.moment;
                    loaded.add(found);
                    eval(xhr.responseText); // Because HTML5 doesn't execute dynamic script tag

                    moment.locale(found);
                    callback && callback(found);
                }
            };

            xhr.send();
            return;
        }

        callback && callback(false);
    }
})();

// Example
moment.loadLocale('id_ID', function(found){
    if(found === false)
        return console.error("Language not found");
    
    console.log(moment().format('LLLL'));
});