How to create community service with flet v0.7?

[SamYuan1990]

Hi here, I am try to build my own flet extension as server at github repo:
https://github.com/SamYuan1990/flet_sherpa_onnx

For my self study on code, a flet extension needs:

1. a python library as bridge
2. a dart impl across platform

But I got issue when test it, my test app may blank at the 1st and appears at second.
From Debug log, I can see it did_mount and mount to service reg.

Even if the test app is not broken, I tried to test with function invoke, but with a timeout at python side as result.

I make the python class extend from ft.Service as

import flet as ft
import logging
from typing import Optional

__all__ = ["FletSherpaOnnx"] 
# this will mapping my python code to dart

@ft.control("FletSherpaOnnx")
class FletSherpaOnnx(ft.Service):
    """
    FletSherpaOnnx Control description.
    """
    print("we are here")

    async def test(self, timeout: Optional[float] = 10) -> Optional[str]:
        print("method testing")
        return await self._invoke_method(
            method_name="test_method",
            arguments={},
            timeout=timeout,
        )

and my dart as

library flet_sherpa_onnx;

export "src/extension.dart" show Extension;

with

import 'package:flet/flet.dart';

import 'fletsherpaonnx.dart';

class Extension extends FletExtension {
  @override
  FletService? createService(Control control) {
    switch (control.type) {
      // here is the mapping on dart part.
      case "FletSherpaOnnx":
        return FletSherpaOnnxService(control: control);
      default:
        return null;
    }
  }
}

and impl

import 'dart:async';

import 'package:flet/flet.dart';

class FletSherpaOnnxService extends FletService {
  FletSherpaOnnxService({required super.control});

  @override
  void init() {
    super.init();
    debugPrint("FletSherpaOnnxService(${control.id}).init: ${control.properties}");
    control.addInvokeMethodListener(_invokeMethod);
  }

  @override
  void dispose() {
    debugPrint("FletSherpaOnnxService(${control.id}).dispose()");
    control.removeInvokeMethodListener(_invokeMethod);
    super.dispose();
  }

  Future<dynamic> _invokeMethod(String name, dynamic args) async {
    debugPrint("FletSherpaOnnxService.$name($args)");
    // just here swtich the functions
    switch (name) {
      case "test_method":
        return "response from dart";
      default:
        throw Exception("Unknown FletSherpaOnnxService method: $name");
    }
  }
}

[SamYuan1990]

I see, it needs a build before for flutter packages.