pulyaevskiy · December 14, 2018 05:20 · Dec 14, 2018 · Dec 14, 2018
diff --git a/main.dart b/main.dart
@@ -32,11 +32,9 @@ void main() {
     conv.ask('Your ssml goes here...');
   }));
 
-  // I'm not sure if you actually need to export a firebase function from this
-  // script. Actions documentation never mentioned this.
-  // I suspect you'd need separate build targets for actions and for functions
-  // which could simply be just separate files in your node/ folder.
-  // The below line likely won't compile because [app] has wrong type.
+  // This won't actually work currently as firebase_functions_interop expects a Dart function
+  // in onRequest. This can be easily fixed by updating the package to support actionssdk
+  // or expose native JS object to interact with directly.
   functions['sayNumber'] = functions.https.onRequest(app);
 }
 

diff --git a/main.dart b/main.dart
@@ -0,0 +1,112 @@
+/// This is pseudo-code which drafts possible way of using Google's `actions-on-google` Node.js package.
+/// This code has not been tested, compiled or ran anywhere.
+@JS()
+library actionssdk;
+
+import 'package:firebase_functions_interop/firebase_functions_interop.dart';
+import 'package:js/js.dart';
+import 'package:js/js_util.dart';
+import 'package:node_interop/node_interop.dart';
+
+void main() {
+  final app = actionssdk(ActionsSDKAppOptions(debug: true));
+  // Note that Dart functions cannot be passed to JS as-is and must be
+  // wrapped with allowInterop or allowInteropCaptureThis
+  app.intent('actions.intent.MAIN', allowInterop((ActionsSDKConversation conv,
+      [String input, Argument argument, GoogleRpcStatus status]) {
+    conv.ask('Your ssml goes here');
+    // If above call fails when deployed we might need to use callMethod:
+    callMethod(conv, 'ask', ['Your ssml goes here']);
+    // As you can see in firebase_admin_interop and functions interop
+    // I abstract away all these details from the user so that they only
+    // need to deal with pure Dart.
+  }));
+
+  app.intent('actions.intent.MAIN', allowInterop((ActionsSDKConversation conv,
+      [String input, Argument argument, GoogleRpcStatus status]) {
+    if (input == 'bye') {
+      // The `close` method is similar to `ask` method so might need the `callMethod`
+      // approach
+      conv.close('Goodbye!');
+    }
+    conv.ask('Your ssml goes here...');
+  }));
+
+  // I'm not sure if you actually need to export a firebase function from this
+  // script. Actions documentation never mentioned this.
+  // I suspect you'd need separate build targets for actions and for functions
+  // which could simply be just separate files in your node/ folder.
+  // The below line likely won't compile because [app] has wrong type.
+  functions['sayNumber'] = functions.https.onRequest(app);
+}
+
+// This loads Node.js package
+// Note that you need to have it in your package.json
+final ActionsSDKExports _actionsOnGoogleExports = require('actions-on-google');
+// This provides access to the actionssdk only
+final ActionsSDKAppFactory actionssdk = _actionsOnGoogleExports.actionssdk;
+
+/// Here we define interface of exports provided by Node.js package.
+@JS()
+@anonymous
+abstract class ActionsSDKExports {
+  // For this example we only declare the actionssdk binding, but can add more if needed.
+  external ActionsSDKApp actionssdk(ActionsSDKAppOptions options);
+}
+
+typedef ActionsSDKAppFactory = ActionsSDKApp Function(
+    ActionsSDKAppOptions options);
+
+/// Here we define interface that's expected for the actionssdk.
+@JS()
+@anonymous
+abstract class ActionsSDKApp {
+  // Rough approximation of method signature from here:
+  // https://actions-on-google.github.io/actions-on-google-nodejs/interfaces/actionssdk.actionssdkapp.html#intent
+  // [intent] here can be either single value or an array, so had to declare
+  // as dynamic
+  external ActionsSDKApp intent(
+      dynamic intent, ActionsSdkIntentHandler handler);
+}
+
+// This is how to declare basic JSON-like objects so that it's easy to use
+// On the Dart side. Mostly useful for things like options (this case)
+@JS()
+@anonymous
+abstract class ActionsSDKAppOptions {
+  external bool get debug;
+  // Must have external factory
+  external factory ActionsSDKAppOptions({bool debug});
+}
+
+/// All the bindings continued...
+/// You have to declare everything you're going to use.
+
+/// This is rough approximation of signature from here:
+/// https://actions-on-google.github.io/actions-on-google-nodejs/interfaces/actionssdk.actionssdkintenthandler.html
+typedef ActionsSdkIntentHandler = dynamic Function(ActionsSDKConversation conv,
+    [String input, Argument argument, GoogleRpcStatus status]);
+
+@JS()
+@anonymous
+abstract class ActionsSDKConversation {
+  // Type definition for ask seems like it could be a variadic function
+  // in which case we won't be able to just call `conv.ask('something')` and
+  // will have to invoke it using [callMethod].
+  external ActionsSDKConversation ask(dynamic responses);
+  // The same applies to this method.
+  external ActionsSDKConversation close(dynamic responses);
+  // ...
+}
+
+@JS()
+@anonymous
+abstract class Argument {
+  // ...
+}
+
+@JS()
+@anonymous
+abstract class GoogleRpcStatus {
+  // ...
+}