From e3823803aadce7902d3bd68a75ca20f662b69ee5 Mon Sep 17 00:00:00 2001
From: Pavel Djundik <github@xpaw.me>
Date: Fri, 1 Dec 2017 20:04:50 +0200
Subject: [PATCH] Handle javascript errors while loading

---
 client/index.html               |  2 +-
 client/js/loading-slow-alert.js | 15 +++++++++++++++
 client/js/socket-events/init.js |  5 +++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/client/index.html b/client/index.html
index 78051d25..e51999d7 100644
--- a/client/index.html
+++ b/client/index.html
@@ -48,7 +48,7 @@
 					<div class="container">
 						<div class="row">
 							<div class="col-xs-12">
-								<h1 class="title">The Lounge is loading…</h1>
+								<h1 class="title" id="loading-title">The Lounge is loading…</h1>
 							</div>
 							<div class="col-xs-12">
 								<p id="loading-page-message">Loading the app… <a href="http://enable-javascript.com/" target="_blank" rel="noopener">Make sure to have JavaScript enabled.</a></p>
diff --git a/client/js/loading-slow-alert.js b/client/js/loading-slow-alert.js
index debff175..1029004e 100644
--- a/client/js/loading-slow-alert.js
+++ b/client/js/loading-slow-alert.js
@@ -19,3 +19,18 @@ setTimeout(function() {
 document.getElementById("loading-slow-reload").addEventListener("click", function() {
 	location.reload();
 });
+
+window.g_LoungeErrorHandler = function LoungeErrorHandler(error) {
+	var title = document.getElementById("loading-title");
+	title.textContent = "An error has occured";
+
+	title = document.getElementById("loading-page-message");
+	title.textContent = "An error has occured that prevented the client from loading correctly.";
+
+	var element = document.createElement("p");
+	element.contentEditable = true;
+	element.textContent = error instanceof ErrorEvent ? error.message : error;
+	title.parentNode.insertBefore(element, title.nextSibling);
+};
+
+window.addEventListener("error", window.g_LoungeErrorHandler);
diff --git a/client/js/socket-events/init.js b/client/js/socket-events/init.js
index 19e82ef3..7dae4c94 100644
--- a/client/js/socket-events/init.js
+++ b/client/js/socket-events/init.js
@@ -44,6 +44,11 @@ socket.on("init", function(data) {
 		$("body").removeClass("signed-out");
 		$("#loading").remove();
 		$("#sign-in").remove();
+
+		if (window.g_LoungeErrorHandler) {
+			window.removeEventListener("error", window.g_LoungeErrorHandler);
+			window.g_LoungeErrorHandler = null;
+		}
 	}
 
 	openCorrectChannel(previousActive, data.active);