protoc-gen-connect-dart

A protoc plugin for generating a Connect client for Dart. The generated client only supports unary requests and is suitable for any supported Dart platform.

This plugin is based off of apptreesoftware/protoc-gen-twirp_dart and modifications from marwan-at-work/protoc-gen-twirp_dart. The code was modified to remove all of the JSON type generation, and the actual RPC calls are made using the ska_connect supporting package.

Installation

The protobuf v3 compiler is required. You can get the latest precompiled binary for your system here. In addition Go 1.18 or higher is required. The executable can be installed with the following command:

go install github.com/skadero/protoc-gen-connect-dart

Example Go Server (optional)

While not required, the example directory contains a Go based server implementation that requires:

go install github.com/bufbuild/connect-go/cmd/protoc-gen-connect-go@latest
go install github.com/golang/protobuf/protoc-gen-go

Using

The generated code requires the following Dart packages in your pubspec.yaml:

ska_connect: ^1.0.1

An example command for compiling protoc files:

protoc --proto_path=./example/proto  --dart_out=./example/dart_client/rpc --connect-dart_out=./example/dart_client/rpc ./example/proto/haberdasher/haberdasher.proto ./example/proto/pinger/ping.proto

Which outputs the generated code to ./example/dart_client/rpc. Example of Connect calls from generated code:

import 'dart:async';

import "package:ska_connect/ska_connect.dart";
import 'package:http/http.dart' as http;
import 'rpc/haberdasher/haberdasher.connect.dart' as ha;
import 'rpc/haberdasher/haberdasher.pb.dart';
import 'rpc/pinger/ping.pb.dart';

Future main(List<String> args) async {
  final hClient = http.Client();
  final client = HttpConnectClient('http://localhost:9080', hClient);

  final hService = ha.HaberdasherClient(client);

  final hatResponse = await hService.makeHat(Size(inches: 6));
  print(hatResponse.response);

  final invResponse = await hService.invalidArg(PingRequest(name: "example"));
  if (invResponse.isError) {
    print(invResponse.error!.code);
  }
  hClient.close();
}