将 iOS 事件传递给 Ionic/Capacitor webview

Question

I am looking for a way to pass an event to the frontend of an Ionic/Capacitor app from iOS/Swift, The end goal is to retro-fit this code so that I can process a 3rd party push notification provider. The flow is that the app loads and passes the notification data to my Capacitor plugin so that I can make use of the bridge methods (maybe I can do this from AppDelegate directly ?) and in my plugin I have an observable ready to receive the notification which it then passes to a method that executes the events as per the Capacitor documentation, however no event every gets fired and no alert pops, potentially this is because the AppDelegate and plugin loads before the webview but in that care Im not sure how to process this.

AppDelegate.swift

  func applicationDidBecomeActive(_ application: UIApplication) {
    let nc = NotificationCenter.default
    nc.post(name: Notification.Name("TestingEvents"), object: nil)
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was
  }

MyPlugin.swift

    public override func load() {
        let nc = NotificationCenter.default
            nc.addObserver(self, selector: #selector(handleSignal), name: Notification.Name("TestingEvents"), object: nil)
    }

    @objc func handleSignal() {
        self.bridge.triggerWindowJSEvent(eventName: "myCustomEvent")
        self.notifyListeners("myPluginEvent", data: [:])
    }

and my app.component.ts

      window.addEventListener('myCustomEvent', () => {
        console.log("ATTEMPTILE PUSH")
        alert("myCustomEvent 2 ")
      });            
      Plugins.myPlugin.addListener("myPluginEvent", (info: any) => {
        console.log("myPluginEvent was fired");
        alert("myPluginEvent 2 ")
      });

Answer 1

What you can do to archive this (one Solution i used in a Plugin):

Your Plugin has a js File in the www Folder, which manages the Functions. In this File you can create Methods to create listener, remove listener, fireEvent:

exports._listener = {};

/**
 * Fire event with given arguments.
 *
 * @param [ String ] event The event's name.
 * @param [ Array<Object> ] The callback's arguments.
 *
 * @return [ Void ]
 */
exports.fireEvent = function (event)
{
    var args     = Array.apply(null, arguments).slice(1),
        listener = this._listener[event];

    if (!listener)
        return;

    for (var i = 0; i < listener.length; i++)
    {
        var fn    = listener[i][0],
            scope = listener[i][1];

        fn.apply(scope, args);
    }
};

/**
 * Register callback for given event.
 *
 * @param [ String ] event The event's name.
 * @param [ Function ] callback The function to be exec as callback.
 * @param [ Object ] scope The callback function's scope.
 *
 * @return [ Void ]
 */
exports.on = function (event, callback, scope)
{
    if (typeof callback !== "function")
        return;

    if (!this._listener[event])
    {
        this._listener[event] = [];
    }

    var item = [callback, scope || window];

    this._listener[event].push(item);
};

/**
 * Unregister callback for given event.
 *
 * @param [ String ] event The event's name.
 * @param [ Function ] callback The function to be exec as callback.
 *
 * @return [ Void ]
 */
exports.un = function (event, callback)
{
    var listener = this._listener[event];

    if (!listener)
        return;

    for (var i = 0; i < listener.length; i++)
    {
        var fn = listener[i][0];

        if (fn == callback)
        {
            listener.splice(i, 1);
            break;
        }
    }
};

Maybe you have to edit these a bit, to match for what you want. Then you need the Connection to your Native Code, this could be archived with calling a Methode on Plugin startup like this:

channel.onCordovaReady.subscribe(function () {
  cordova.exec(function(event) {
    // Callback from Native Code received. Fire to JS Listeners
    this.fireEvent(event);
  }, null, 'YourPluginName', 'init', []);
}

then you need a Function (Objective-C as i don't so Swift much) called init(), which just saves the CallbackId:

- (void) init:(CDVInvokedUrlCommand *)command
{
    self.eventCallbackId = command.callbackId;
    return;
}

Then you can emit something to the CallbackId via:

CDVPluginResult* result = [CDVPluginResult resultWithStatus:CDVCommandStatus_OK messageAsString:@"event"];
[self.commandDelegate sendPluginResult:result callbackId:self.eventCallbackId];