Mimic Window. onerror in Opera using javascript

Question

I am currently working on a web application, I have a JS logging mechanism that Handles Javascript error that are not caught by the js code inside the page. I am using windo

Answer 1

This also happens on Safari, AFAIK.

What you could certainly do is create a global try/catch block for all JS code instead of text parsing - which could be tricky if you come into things like:

(function ($){
  $(function (){
  });
})(jQuery);

Answer 2

Opera 11.60+ supports window.onerror.

Opera's Dragonfly supports remote debugging. You might be able to hack it (it's all written in JavaScript) and log errors yourself (unfortunately the protocol isn't published yet).

Answer 3

you can replace Error.prototype.toString in Opera!

window.onerror = function (msg) {
  // send msg to http://errors.net/log.php, for example
  (new Image()).src = 'http://errors.net/log.php?msg=' + encodeURIComponent(msg);
};
if (({}).toString.call(window.opera) === '[object Opera]') {
 (function () {
   var x = Error.prototype.toString;
   Error.prototype.toString = function () {
     var msg = '';
     try {
       msg = x.apply(this, arguments);
       if (typeof (window.onerror) === "function") {
         window.onerror(msg, typeof (this) === 'object' ? this.stack : '', '');
       }
     } catch (e) {}
     return msg;
   };
 }());
}

seems, it doesn't work for Opera 11.50... only for early versions ...

Answer 4

there is a mention here that Opera now supports window.onerror:

http://my.opera.com/ODIN/blog/2011/11/07/what-s-new-in-opera-development-snapshots-4-november-2011-edition

but window.onerror does not seem to work in Opera Mini (e.g. user agent "Opera/9.80 (J2ME/MIDP; Opera Mini/7.1.32422/30.3214; U; en) Presto/2.8.119 Version/11.10"). This makes it really hard to debug javascript on mobiles with Opera Mini.