fix #150: Active app is not visible has active in menu (except in default menu).

src/SideMenuBig.vue

@@ -60,6 +60,7 @@ import CloserButton from './CloserButton'
 import SettingsButton from './SettingsButton'
 import Loader from './Loader'
 import SideMenuBigApp from './SideMenuBigApp'
+import { loadState } from '@nextcloud/initial-state'
 
 export default {
   name: 'SideMenuBig',
@@ -100,8 +101,13 @@ export default {
     },
 
     retrieveActiveApp() {
-      let activeAppLink = document.querySelector('#appmenu a.active')
-      this.activeApp = activeAppLink ? activeAppLink.parentNode.getAttribute('data-id') : null
+      const ncApps = loadState('core', 'apps', {})
+
+      for (let id in ncApps) {
+        if (ncApps[id].active) {
+          this.activeApp = id
+        }
+      }
     },
 
     retrieveConfig() {