Offline hits

Foreword

The AT Internet SDK enables you to store, on the user’s device, any hits that couldn’t be sent due to loss of Internet connection. For this, the SDK uses Apple’s CoreData technology.

Use of this feature is subject to the subscription to an option. This feature may increase the disk space that your application occupies on a user’s device.

Setting up the storage mode

You can set up the storage management mode directly within the Tag Composer interface, or via the Tracker’s setConfig method.

Three modes are available:

• required : Hits are only stored when a loss of connection is detected.
• always : Hits are never sent. They are directly stored on the device.
• never (by default) : Hits are never stored. If a loss of connection is detected at the same time as an attempt to send the hit, the hit will be lost.

To edit the hit storage mode, add the following code to the desired area:

Store hits during loss of connection:

tracker.setOfflineMode(OfflineModeKey.required, completionHandler: nil) // Notice that the function is async

[self.tracker setConfig:@"storage" value:@"required" completionHandler:nil];

This method sends all stored hits in an asynchronous manner, and deletes them if the send was successful. If the send failed, two new attempts will be made during the next hit send. If all attempts fail, the hit will be deleted from storage.

Thanks to this method, you may decide at which moment you want hits to be sent. By setting the storage mode to always, you can simply call the send method to trigger sending at the desired moment.

Sending hits in the background

You may trigger the sending of saved hits during time your application runs in the background. To do this, add the following code in your application delegate:

func applicationDidEnterBackground(_ application: UIApplication) {
    self.tracker.offline.dispatch()
}

- (void)applicationDidEnterBackground:(UIApplication *)application {
    [self.tracker.offline dispatch];
}