Logging full NSException stack traces to your server

*UPDATE* I am using Crashlytics instead now and it’s awesome, go check it out!

Recently in You Doodle I discovered a couple of nasty crashes happening to users by looking in my Flurry Analytics error logs. Unfortunately flurry decides to truncate errors so you don’t get much useful out of it.

I decided I would write a logger to my own server and pass the full exception details. Here’s how I did it:

In my AppDelegate didFinishLaunching, I call this:

NSSetUncaughtExceptionHandler(&uncaughtExceptionHandler);

At the top of my AppDelegate.m file I have this function:

static void uncaughtExceptionHandler(NSException* exception)
{

#ifdef APP_STORE

NSArray* backtrace = [exception callStackSymbols];
NSString* platform = [[UIDevice currentDevice] getHardwareName];
NSString* version = [[UIDevice currentDevice] systemVersion];
NSString* message = [NSString stringWithFormat:@"Device: %@. OS: %@. Backtrace:\n%@", platform, version, backtrace];

DeviceLogRequest* req = [[DeviceLogRequest alloc] initWithText:message];
[req makeRequestWithBlock:nil];

[FlurryAnalytics logError:@"Uncaught" message:message exception:exception];

// give everything 2 seconds to fire off
[[NSRunLoop currentRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:2.0f]];

#endif

}

The logging to my server happens in DeviceLogRequest. Basically it does some magic and sends an http post request to a secure end point where the error details, including the full stack trace, are logged into my database for troubleshooting. You’ll still need to de-symbolicate crash addresses manually, but at least you will have the crash log!

Hopefully someone else finds this useful too!