app/error-handler.js

   1 /*
   2  * noVNC: HTML5 VNC client
   3  * Copyright (C) 2019 The noVNC Authors
   4  * Licensed under MPL 2.0 (see LICENSE.txt)
   5  *
   6  * See README.md for usage and integration instructions.
   7  */
   8
   9 // NB: this should *not* be included as a module until we have
  10 // native support in the browsers, so that our error handler
  11 // can catch script-loading errors.
  12
  13 // No ES6 can be used in this file since it's used for the translation
  14 /* eslint-disable prefer-arrow-callback */
  15
  16 (function _scope() {
  17     "use strict";
  18
  19     // Fallback for all uncought errors
  20     function handleError(event, err) {
  21         try {
  22             const msg = document.getElementById('noVNC_fallback_errormsg');
  23
  24             // Only show the initial error
  25             if (msg.hasChildNodes()) {
  26                 return false;
  27             }
  28
  29             let div = document.createElement("div");
  30             div.classList.add('noVNC_message');
  31             div.appendChild(document.createTextNode(event.message));
  32             msg.appendChild(div);
  33
  34             if (event.filename) {
  35                 div = document.createElement("div");
  36                 div.className = 'noVNC_location';
  37                 let text = event.filename;
  38                 if (event.lineno !== undefined) {
  39                     text += ":" + event.lineno;
  40                     if (event.colno !== undefined) {
  41                         text += ":" + event.colno;
  42                     }
  43                 }
  44                 div.appendChild(document.createTextNode(text));
  45                 msg.appendChild(div);
  46             }
  47
  48             if (err && err.stack) {
  49                 div = document.createElement("div");
  50                 div.className = 'noVNC_stack';
  51                 div.appendChild(document.createTextNode(err.stack));
  52                 msg.appendChild(div);
  53             }
  54
  55             document.getElementById('noVNC_fallback_error')
  56                 .classList.add("noVNC_open");
  57         } catch (exc) {
  58             document.write("noVNC encountered an error.");
  59         }
  60         // Don't return true since this would prevent the error
  61         // from being printed to the browser console.
  62         return false;
  63     }
  64     window.addEventListener('error', function onerror(evt) { handleError(evt, evt.error); });
  65     window.addEventListener('unhandledrejection', function onreject(evt) { handleError(evt.reason, evt.reason); });
  66 })();