Developing for Apple Watch, 2nd Edition

Talking to the iPhone with WatchConnectivity

Talking to remote servers in a data center somewhere is an important task for any app, but sometimes on the watch it seems redundant. Why talk to a server on another continent when there’s a perfectly good iPhone just a Bluetooth connection away? That’s where the WatchConnectivity framework comes in. Often, we just want to send small bits of data back and forth between the two devices—preferences, small images, or user documents, for instance. WatchConnectivity serves as a bridge between the two apps—in fact, you’ll use the framework on both iOS and watchOS. There are several ways to transfer data back and forth using WatchConnectivity. As we go through them, you’ll implement TapALap’s ...