How to pass/parse server data to objects in WatchKit table rows? - json

Question

My tutorial is a WhatsApp/SnapChat app. Naturally the avatar image, country flag, user name, gender symbol and conversation data all come from the server and host app.
These kinds of apps do not use Parse like APIs or other 3rd party dependencies because they use REST/JSON with their own servers.
How do I get this same data and UI elements onto the watch table row? Do we have to re-write the same HTTP GET methods in our watch extension as well as re-copy UI elements into watchOS cassettes folder? Can we not just call the same methods that already exist in the iOS host app? I'm not sure how the Connectivity Framework would be used.
Could you please give an example of GET and POST methods to assign an avatar or username to the watch table row view object? For example for a Node.js server.

Answer 1

Since your iOS host app has already downloaded and deserialized the data, it doesn't make any sense for the watch to duplicate that code or effort and GET the same data.
As for providing an example, you should show what you tried in code, and explain the specific problem you're having.
Documentation
You should use the Watch Connectivity framework to share data between your iOS and watchOS apps.
You'll find a good introduction in the watchOS 2 Transition Guide. See Communicating with Your Companion iOS App for details.
Apple also provides Lister sample code which demonstrates how to use WCSession to transfer both application context and files between iOS and watchOS.
Since the host app is written in Obj-C should WatchConnectivity / WCSessionDelegate be imported into every file header file that contains data that needs to be sent to the watch extension?
WCSession is a singleton that you configure at launch time, early in the life of both your iOS app and watch extension. See the transition guide's Activating the Session Object for more information.
If you don't understand how or where your apps should handle watch connectivity, there are plenty of tutorials and sample projects which you can easily find via Google.
So based on what you said I just need to use the Connectivity Framework. sendMessageToWatch and didReceiveMessage methods.
The exact methods you use depend on what you want to transfer -- application context, user info, files, or messages -- and whether it takes place in the foreground or background. See the transition guide's Choosing the Right Communication Option for more information.

Answer 2

If you check some chat app projects that are already on GitHub you will see how to use Connectivity Framework precisely. Obj-C and Swift.
Here's one that specifically shows you how to pass messages back and forth.
https://github.com/carbamide/MessagingTest
This is not my code. As you can see code is almost the same.
ViewController.swift
override func awakeWithContext(context: AnyObject?) {
super.awakeWithContext(context)
if (WCSession.isSupported()) {
let session = WCSession.defaultSession()
session.delegate = self
session.activateSession()
}
}
func session(session: WCSession, didReceiveApplicationContext applicationContext: [String : AnyObject]) {
print(applicationContext)
let okButton = UIAlertAction(title: "OK", style: .Default, handler: nil)
let alert = UIAlertController(title: "Application Context Received", message: applicationContext.description, preferredStyle: .Alert)
alert.addAction(okButton)
self.presentViewController(alert, animated: true, completion: nil)
}
watchOS InterfaceController.swift
func session(session: WCSession, didReceiveApplicationContext applicationContext: [String : AnyObject]) {
print(applicationContext)
let okButton = WKAlertAction(title: "OK", style: WKAlertActionStyle.Default, handler: { () -> Void in })
self.presentAlertControllerWithTitle("Application Context Received", message: applicationContext.description, preferredStyle: .Alert, actions: [okButton])
}