I’m unsure what errors 2-5 are. There’s no associated file, and the error message is simply “Script error”. The Analyzer gets an average of 90 visitors a day, so these account for a small percentage of users, though it is a little peculiar. Error 1 is definitely a real error though. I had been checking the stats every day, so when it popped up I actually got a little excited.
Usually when I discover an error, it stings. Users don’t often tell you about errors, unless they really like the app or are feeling unusually nice. Often times they may not even know something’s wrong. If the app wont work correctly, they just move on to another page without another thought.
This time, I caught it right after it happened, so I was actually a little happy. The error was pretty easy to pinpoint. Luckily it only occurred if AltGr keys were used, which doesn’t effect users unless they decide to add customizations for foreign layouts, which is why it didn’t show up until later in the week. I should have caught this while testing, but over sights are made sometimes.
So far I’m happy with this little experiment, and am thinking about possibly adding client side error logging to my other apps. For now the only draw backs I see are that this method of discovering errors can be a hassle if your scripts are minified and concatenated, and that users could abuse this if they knew you were doing it (though then again, they could abuse any kind of data saving request you were doing).