How can I programmatically compose a message on Watch?

Question

How can I open the Messages app to the compose screen, with the message body preloaded with specific text?

Answer 1

Thanks to @Jatin for finding the openSystemURL(url: NSURL) function.

Here's the code:

let messageBody = "Hello World!"
let urlSafeBody = messageBody.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLQueryAllowedCharacterSet())!
WKExtension.sharedExtension().openSystemURL(NSURL(string: "sms:&body=\(urlSafeBody)")!)