Flutter - How to invoke channel in native Swift code? - ios

Question

I have written native Swift code in my AppDelegate, I am trying to invoke a third party sdk callback in my dart side of code, however the declaration of my method channel can only be done in application function. How do I invoke a channel in my delegate methods to make a dart callback?
import UIKit
import Flutter
#UIApplicationMain
#objc class AppDelegate: FlutterAppDelegate, TJPlacementDelegate {
public func requestDidSucceed(_ placement: TJPlacement!) {
//Need to invoke methodChannel here
}
public func requestDidFail(_ placement: TJPlacement!, error: Error!) {
//Need to invoke methodChannel here
}
public func contentIsReady(_ placement: TJPlacement!) {
//Need to invoke methodChannel here
}
override func application(
_ application: UIApplication,
didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
) -> Bool {
let channelName = "ios_native"
let rootViewController : FlutterViewController = window?.rootViewController as! FlutterViewController
let methodChannel = FlutterMethodChannel(name: channelName, binaryMessenger: rootViewController as! FlutterBinaryMessenger)
methodChannel.setMethodCallHandler {(call: FlutterMethodCall, result: FlutterResult) -> Void in
switch(call.method) {
case "setDebugEnabled":
let isDebug = call.arguments as! Bool
Tapjoy.setDebugEnabled(isDebug)
break;
default: result(FlutterMethodNotImplemented)
}
}
GeneratedPluginRegistrant.register(with: self)
return super.application(application, didFinishLaunchingWithOptions: launchOptions)
}
}
I can't declare my methodChannel outside my application as the window doesn't get recognised.

Answer 1

Define the method channel in the AppDelegate:
var methodChannel: FlutterMethodChannel!
Initialize it:
override func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
) -> Bool {
...
methodChannel = FlutterMethodChannel(name: channelName, binaryMessenger: rootViewController as! FlutterBinaryMessenger)
}
Now you can call invokeMethod:
public func requestDidSucceed(_ placement: TJPlacement!) {
methodChannel.invokeMethod()
}