drect.js

function DRect() {
    this.serverEl = document.getElementById('server');
    this.progressEl = document.getElementById('progress');

    this.init()
}

DRect.prototype.init = function () {
    var id = this.getID();

    if (id === undefined) {
        this.serverEl.classList.add('visible');
    } else {
        this.getData(id, this.populate);
    }

    if ('serviceWorker' in navigator) {
        navigator.serviceWorker.register('sw.js', {scope: '/'}).then(function () {
            console.log("Service Worker Registered");
        });
    }
};

DRect.prototype.getID = function () {
    return location.hash.slice(1) || undefined;
};

DRect.prototype.getData = function (id, callback) {
    var myself = this;

    var url = 'https://discordapp.com/api/guilds/' + id.toString() + '/widget.json';

    var xhr = new XMLHttpRequest();
    xhr.onreadystatechange = function () {
        if (this.readyState === 4) {
            var responseJSON = JSON.parse(this.responseText);

            if (this.status === 200) {
                callback.call(myself, responseJSON);
            } else {
                callback.call(myself, {name: responseJSON.message || 'Invalid ID', instant_invite: null})
            }
        }
    };
    xhr.onerror = function () {
        callback.call(myself, {name: "Connection Error", instant_invite: null});
    };
    xhr.open('GET', url, true);
    xhr.send();
};

DRect.prototype.populate = function (data) {
    this.serverEl.innerText = data.name;
    this.serverEl.classList.add('visible');

    if (data.instant_invite) {
        this.progressEl.classList.add('full');
        setTimeout(function () {
            location.href = data.instant_invite;
        }, 3e3);
    }
};

drect = new DRect();