use apiLoad event

plugins/precise-volume/front.js

@@ -3,26 +3,15 @@ const { ipcRenderer, remote } = require("electron");
 const { setOptions } = require("../../config/plugins");
 
 function $(selector) { return document.querySelector(selector); }
-let api = $('#movie_player');
+let api;
 
 module.exports = (options) => {
-	if (api) {
+	document.addEventListener('apiLoaded', e => {
+		api = e.detail;
 		firstRun(options);
-		return;
-	}
-
-	const observer = new MutationObserver(() => {
-		api = $('#movie_player');
-		if (api) {
-			observer.disconnect();
-			firstRun(options);
-		}
 	})
-
-	observer.observe(document.documentElement, { childList: true, subtree: true });
 };
 
-
 /** Restore saved volume and setup tooltip */
 function firstRun(options) {
 	if (typeof options.savedVolume === "number") {
@@ -93,10 +82,6 @@ function setupVideoPlayerOnwheel(options) {
 	});
 }
 
-function toPercent(volume) {
-	return Math.round(Number.parseFloat(volume) * 100);
-}
-
 function saveVolume(volume, options) {
 	options.savedVolume = volume;
 	writeOptions(options);

preload.js

@@ -10,6 +10,8 @@ const setupSongInfo = require("./providers/song-info-front");
 
 const plugins = config.plugins.getEnabled();
 
+let api;
+
 plugins.forEach(([plugin, options]) => {
 	const preloadPath = path.join(__dirname, "plugins", plugin, "preload.js");
 	fileExists(preloadPath, () => {
@@ -38,6 +40,9 @@ document.addEventListener("DOMContentLoaded", () => {
 		});
 	});
 
+	// wait for complete load of youtube api
+	listenForApiLoad();
+
 	// inject song-info provider
 	setupSongInfo();
 
@@ -51,3 +56,25 @@ document.addEventListener("DOMContentLoaded", () => {
 	global.reload = () =>
 		remote.getCurrentWindow().webContents.loadURL(config.get("url"));
 });
+
+function listenForApiLoad() {
+	api = document.querySelector('#movie_player');
+	if (api) {
+		onApiLoaded();
+		return;
+	}
+
+	const observer = new MutationObserver(() => {
+		api = document.querySelector('#movie_player');
+		if (api) {
+			observer.disconnect();
+			onApiLoaded();
+		}
+	})
+
+	observer.observe(document.documentElement, { childList: true, subtree: true });
+}
+
+function onApiLoaded() {
+	document.dispatchEvent(new CustomEvent('apiLoaded', { detail: api }));
+}