streamer as separate application; working streamer monitor interface

assets/public/app.js

@@ -1,17 +1,53 @@
 import Vue from 'vue';
 
 
-export var app = null;
-export default app;
+export const appBaseConfig = {
+    el: '#app',
+    delimiters: ['[[', ']]'],
+}
 
-function loadApp() {
-    app = new Vue({
-      el: '#app',
-      delimiters: [ '[[', ']]' ],
+/**
+ * Application config for the main application instance
+ */
+var appConfig = {};
+
+export function setAppConfig(config) {
+    for(var member in appConfig) delete appConfig[member];
+    return Object.assign(appConfig, config)
+}
+
+export function getAppConfig(config) {
+    if(config instanceof Function)
+        config = config()
+    config = config == null ? appConfig : config;
+    return {...appBaseConfig, ...config}
+}
+
+
+/**
+ * Create Vue application at window 'load' event and return a Promise
+ * resolving to the created app.
+ *
+ * config: defaults to appConfig (checked when window is loaded)
+ */
+export function loadApp(config=null) {
+    return new Promise(function(resolve, reject) {
+        window.addEventListener('load', function() {
+            try {
+                config = getAppConfig(config)
+                const el = document.querySelector(config.el)
+                if(!el) {
+                    reject(`Error: missing element ${config.el}`);
+                    return;
+                }
+
+                resolve(new Vue(config))
+            }
+            catch(error) { reject(error) }
+        })
     })
 }
 
-window.addEventListener('load', loadApp);