Create a gist so I can download it and use it later :P

BasicRestfulApi.js

'use strict';

function getTargetUrl() {
    return window.location.origin;
}

function to(url) {
    window.location.href = url;
}

async function getData(url = '', data = {}) {

    var params = new URLSearchParams();
    for (var key in data) {
        params.append(key, data[key]);
    }

    const final_url = getTargetUrl() + url + "?" + params.toString();

    const response = await fetch(final_url, {
        method: 'GET', // GET, POST, PUT, DELETE, etc.
        cache: 'no-cache', // default, no-cache, reload, force-cache, only-if-cached
        credentials: 'include', // include, same-origin, omit
        keepalive: true
    });
    return response;
}

async function sendData(method, url = '', data = {}) {

    var urlencoded = new URLSearchParams();
    for (var key in data) {
        urlencoded.append(key, data[key]);
    }

    const final_url = getTargetUrl() + url;

    const response = await fetch(final_url, {
        method,
        cache: 'no-cache',
        credentials: 'include', // include cookie
        headers: {
            // 'Content-Type': 'application/json'
            'Content-Type': 'application/x-www-form-urlencoded'
        },
        body: urlencoded,
        keepalive: true
    });
    return response;
}

async function postData(url = '', data = {}) {
    return await sendData('POST', url, data);
}

async function putData(url = '', data = {}) {
    return await sendData('PUT', url, data);
}