javascript: how to display script errors in a popup alert?

Question

I want to display script errors in a popup alert instead of showing them in the browser console.

window.onerror = function() {
  var message = /* get error messages and put them here */;
  alert(message);
  return true;
};

Note that the `onerror` event is only supported by IE and Mozilla. — Christian C. Salvadó, Apr 09 '10 at 04:01
So is there a cross-browser solution? I mean, a similar function supported by webkit — powerboy, Apr 09 '10 at 04:05
You mean there are browsers other than IE and Mozilla??? Dang! I need to get out more :) — DVK, Apr 09 '10 at 04:10
Actually it'll be supported (hopefully soon) in WebKit - see http://www.phwinfo.com/forum/comp-lang-javascript/401318-window-onerror-chrome.html#post1867841 — DVK, Apr 09 '10 at 04:12
yep! But I got another problem. Seems that onerror only support those 3 parameters. There is no way to catch an error of a specific name. — powerboy, Apr 09 '10 at 04:30
`onerror` is useful for debugging. You should not be using it for production code. For catching errors the normal course of your scripts you should be using exceptions. — bobince, Apr 09 '10 at 09:11

DVK · Accepted Answer · 2010-04-09T03:56:01.010

Yes, that is the correct way.

See the reference here:

http://www.javascriptkit.com/javatutors/error2.shtml

And explanation of how to see more details of the error here:

http://www.javascriptkit.com/javatutors/error3.shtml

Their example:

window.onerror = function(msg, url, linenumber) {
    alert('Error message: '+msg+'\nURL: '+url+'\nLine Number: '+linenumber);
    return true;
}

If you wish to display a LIST of errors in a single pop-up, it's trickier.

Since the errors occue 1 by 1, you need to do the following:

have window.onerror handler store error details in some array
Check that array periodically - either via a timer, or on every N'th call of window.onerror handler, or both.

When the check happens, process entire array, display contents as desired, and empty out an array

Thx! So the answer is: window.onerror = function(message) { alert(message); return true; }; Just tested! — powerboy, Apr 09 '10 at 04:02

score 3 · Answer 2 · answered Aug 01 '14 at 07:13

Just in case someone would like to use it with jQuery:

$(window).on("error", function(evt) {

    console.log("jQuery error event:", evt);
    var e = evt.originalEvent; // get the javascript event
    console.log("original event:", e);
    if (e.message) { 
        alert("Error:\n\t" + e.message + "\nLine:\n\t" + e.lineno + "\nFile:\n\t" + e.filename);
    } else {
        alert("Error:\n\t" + e.type + "\nElement:\n\t" + (e.srcElement || e.target));
    }
});

score 0 · Answer 3 · answered Apr 09 '10 at 03:51

0

Have a look at The onerror event of the window object, specifically Getting additional details on an error

answered Apr 09 '10 at 03:51

Adriaan Stander

162,879
31
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score 0 · Answer 4 · answered Apr 09 '10 at 03:53

0

Check this out: http://www.javascriptkit.com/javatutors/error3.shtml. Looks like signature is function(message, url, linenumber).

answered Apr 09 '10 at 03:53

Bialecki

30,061
36
87
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score -1 · Answer 5 · edited Jun 20 '17 at 13:11

<script>$(window).on("error", function(evt) {

console.log("jQuery error event:", evt);
var e = evt.originalEvent; // get the javascript event
console.log("original event:", e);
if (e.message) { 
    alert("Error:\n\t" + e.message + "\nLine:\n\t" + e.lineno + "\nFile:\n\t" + e.filename);
} else {
    alert("Error:\n\t" + e.type + "\nElement:\n\t" + (e.srcElement || e.target));
}
});
</script>

javascript: how to display script errors in a popup alert?

5 Answers5

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