browser - Is there a way in JavaScript to listen console events?

Question

I'm trying to write handler for uncaught exceptions and browser warnings in Javascript. All errors and warnings should be sent to server for later review.

Handled exceptions can be caught and easily logged with

console.error("Error: ...");

or

console.warn("Warning: ...");

So they are not problem if they are called from javascript code, even more, unhandled exceptions could be caught with this peace of code:

window.onerror = function(){
    // add to errors Stack trace etc.
   });
}

so exceptions are pretty covered but I've stuck with warnings which browser sends to console. For instance security or html validation warnings. Example below is taken from Google Chrome console

The page at https://domainname.com/ ran insecure content from http://domainname.com/javascripts/codex/MANIFEST.js.

It would be great if there is some event like window.onerror but for warnings. Any thoughts?

Answer 1

You could just wrap the console methods yourself. For example, to record each call in an array:

var logOfConsole = [];

var _log = console.log,
    _warn = console.warn,
    _error = console.error;

console.log = function() {
    logOfConsole.push({method: 'log', arguments: arguments});
    return _log.apply(console, arguments);
};

console.warn = function() {
    logOfConsole.push({method: 'warn', arguments: arguments});
    return _warn.apply(console, arguments);
};

console.error = function() {
    logOfConsole.push({method: 'error', arguments: arguments});
    return _error.apply(console, arguments);
};