Auto-restart the draw socket on close

Signed-off-by: Emmy D'Anello <emmy.danello@animath.fr>

draw/static/draw.js

@@ -108,12 +108,6 @@ document.addEventListener('DOMContentLoaded', () => {
         elem => elem.addEventListener(
             'click', () => document.location.hash = '#' + elem.innerText.toLowerCase()))
 
-    // Open a global websocket
-    socket = new WebSocket(
-        (document.location.protocol === 'https:' ? 'wss' : 'ws') + '://' + window.location.host
-        + '/ws/draw/'
-    )
-
     /**
      * Add alert message on the top on the interface.
      * @param message The content of the alert.
@@ -750,6 +744,12 @@ document.addEventListener('DOMContentLoaded', () => {
         }
     }
 
+    function setupSocket() {
+        // Open a global websocket
+        socket = new WebSocket(
+            (document.location.protocol === 'https:' ? 'wss' : 'ws') + '://' + window.location.host + '/ws/draw/'
+        )
+
         // Listen on websockets and process messages from the server
         socket.addEventListener('message', e => {
             // Parse received data as JSON
@@ -760,7 +760,8 @@ document.addEventListener('DOMContentLoaded', () => {
 
         // Manage errors
         socket.addEventListener('close', e => {
-        console.error('Chat socket closed unexpectedly')
+            console.error('Chat socket closed unexpectedly, restarting…')
+            setupSocket()
         })
 
         // When the socket is opened, set the language in order to receive alerts in the good language
@@ -787,4 +788,7 @@ document.addEventListener('DOMContentLoaded', () => {
                 })
             }
         }
+    }
+
+    setupSocket()
 })