Swiftgram/docs/HowTo-Handle-Crashes-On-Startup-template.md

Introduction

To catch and send crashes that occur while the app is starting up, the app has to get adjusted a little bit to make this work.

The challenges in this scenario are:

• Sending crash reports needs to be asynchronous, otherwise it would block the main thread or bad network conditions could make it even worse
• If the startup takes too long or the main thread is blocking too long, the watchdog process will kill the app
• The app might crash again before the crash report could have been send

HowTo

1. Setup the SDK
2. Check if the app crashed in the last session by checking [BITCrashManager didCrashInLastSession]
3. Check if [BITCrashManager timeintervalCrashInLastSessionOccured] is below a treshhold that you define. E.g. say your app usually requires 2 seconds for startup, and giving sending a crash report some time, you mighe choose 5 seconds as the treshhold
4. If the crash happened in that timeframe, delay your app initialization and show an intermediate screen
5. Implement the BITCrashManagerDelegate protocol methods - (void)crashManager:(BITCrashManager *)crashManager didFailWithError:(NSError *)error; and - (void)crashManagerDidFinishSendingCrashReport:(BITCrashManager *)crashManager; and continue app initialization

Example

@interface BITAppDelegate () <BITCrashManagerDelegate> {}
@end


@implementation BITAppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  [self.window makeKeyAndVisible];

  [[BITHockeyManager sharedHockeyManager] configureWithIdentifier:@"<>"
                                                         delegate:nil];
  
  // optionally enable logging to get more information about states.
  [BITHockeyManager sharedHockeyManager].debugLogEnabled = YES;

  [[BITHockeyManager sharedHockeyManager] startManager];
  
  if ([self didCrashInLastSessionOnStartup]) {
  	// show intermediate UI
  } else {
  	[self setupApplication];
  }
  
  return YES;
}

- (BOOL)didCrashInLastSessionOnStartup {
  return ([[BITHockeyManager sharedHockeyManager].crashmanager didCrashInLastSession] &&
  	[[BITHockeyManager sharedHockeyManager].crashmanager timeintervalCrashInLastSessionOccured] < 5);
}

- (void)setupApplication {
  // setup your app specific code
}

#pragma mark - BITCrashManagerDelegate

- (void)crashManager:(BITCrashManager *)crashManager didFailWithError:(NSError *)error {
  if ([self didCrashInLastSessionOnStartup) {
    [self setupApplication];
  }
}

- (void)crashManagerDidFinishSendingCrashReport:(BITCrashManager *)crashManager {
  if ([self didCrashInLastSessionOnStartup) {
    [self setupApplication];
  }
}

@end