fix issue with loader and refactoring

src/PageLoader.js

@@ -0,0 +1,20 @@
+const createElement = require('./lib/createElement')
+
+const PageLoader = () => {
+  const pageLoader = createElement('div', {id: 'side-menu-loader'})
+  const pageLoaderBar = createElement('div', {id: 'side-menu-loader-bar'})
+
+  pageLoader.appendChild(pageLoaderBar)
+  document.querySelector('body').appendChild(pageLoader)
+
+  let pageLoaderValue = 0
+
+  window.addEventListener('beforeunload', () => {
+    setInterval(() => {
+      pageLoaderBar.style.width = pageLoaderValue.toString() + '%'
+      pageLoaderValue = Math.min(pageLoaderValue + .2, 100)
+    }, 25)
+  })
+}
+
+module.exports = PageLoader

src/SideMenu.js

@@ -20,10 +20,15 @@ import AppMenu from './AppMenu.vue'
 import SideMenu from './SideMenu.vue'
 import SideMenuBig from './SideMenuBig.vue'
 import SideMenuWithCategories from './SideMenuWithCategories.vue'
+import PageLoader from './PageLoader'
+import SMcreateElement from './lib/createElement'
 
 Vue.prototype.OC = OC
 Vue.prototype.t = OC.L10N.translate
 
+window.SMcreateElement = SMcreateElement
+window.PageLoader = PageLoader
+
 const mountSideMenuComponent = () => {
   const container = document.querySelector('#side-menu')
 

src/lib/createElement.js

@@ -0,0 +1,11 @@
+module.exports = (tagName, attributes) => {
+  const element = document.createElement(tagName)
+
+  if (typeof attributes === 'object') {
+    for (let i in attributes) {
+      element.setAttribute(i, attributes[i])
+    }
+  }
+
+  return element
+}