utility-functions.js

function $(elem) {
  return document.querySelector(elem);
}
// let getElement = $('#element');

function hasClass(el, className) {
    return el.classList ? el.classList.contains(className) : new RegExp('(^| )' + className + '( |$)', 'gi').test(el.className);
}
// if(hasClass($('#element'), '.element'))

function addClass(el, className) {
    if (el.classList) {
        el.classList.add(className);
    } else {
        el.className += ' ' + className
    }
}
function removeClass(el, className) {
    if (el.classList) {
        el.classList.remove(className);
    } else {
        el.className = el.className.replace(new RegExp('(^|\\b)' + className.split(' ').join('|') + '(\\b|$)', 'gi'), ' ');
    }
}

function $extendObj(_def, addons) {
    if (typeof addons !== "undefined") {
        for (var prop in _def) {
            if (addons[prop] != undefined) {
                _def[prop] = addons[prop];
            }
        }
    }
}

function addListenerMulti(el, s, fn) {
  s.split(' ').forEach(function(e) {
    return el.addEventListener(e, fn, false);
  });
}
// addListenerMulti('.element', 'mousedown touchstart', startSwipe)

function removeListenerMulti(el, s, fn) {
  s.split(' ').forEach(function(e) {
    return el.removeEventListener(e, fn, false);
  });
}