grpc-dart Documentation

The grpc-dart implementation supports the following platforms and environments:

• Dart native
• Flutter
• Web: Supported via package:grpc/grpc_web.dart (requires grpc-web).
• UDS (Unix Domain Sockets): Supported with Dart SDK version >= 2.8.0.

After setting up the server and prerequisites, follow these steps to run the Dart client in a web environment:

1. Start the server: Use Docker Compose to start the required gRPC-Web infrastructure:

   docker-compose up node-server envoy commonjs-client

2. Install Dart dependencies: Navigate to the example/grpc-web/ directory and run:

   dart pub get

3. Serve the website: Compile and serve the application on port 9000 (to avoid conflict with the default gRPC server port 8080):

   webdev serve web:9000

4. Access the app: Navigate to http://localhost:9000/ in your browser.

The Route Guide example demonstrates unary, client streaming, server streaming, and full duplex RPCs using Dart gRPC libraries. To run the example, navigate to the example/route_guide/ directory and follow these steps:

1. Fetch dependencies using pub get.
2. Start the server using dart bin/server.dart.
3. Start the client using dart bin/client.dart in a separate terminal.

# Get dependencies
$ pub get

# Run the server
$ dart bin/server.dart

# Run the client
$ dart bin/client.dart

The grpc-dart repository provides several specialized examples to demonstrate different gRPC patterns and use cases:

• Unary RPCs: See the helloworld example for a basic demonstration of performing unary calls.
• Google APIs: See the googleapis example to learn how to communicate with Google APIs using the Dart gRPC library.
• Metadata, Cancellation, and Timeouts: See the metadata example for handling custom metadata, managing request cancellation, and implementing timeouts.
• Advanced RPC Patterns: See the route_guide example to learn how to implement Unary, Client Streaming, Server Streaming, and Full Duplex (Bidirectional) RPCs.

To run the metadata example, navigate to the example/metadata/ directory. First, fetch the necessary dependencies using dart pub get. You can then run the server and client in separate terminal sessions.

# Get dependencies
$ dart pub get

# Run the server
$ dart bin/server.dart

# Run the client
$ dart bin/client.dart

To enable gRPC code generation for Dart, you need to install the protoc_plugin via dart pub global activate. Ensure that ~/.pub-cache/bin is added to your system's PATH so the protoc compiler can locate the plugin.

$ dart pub global activate protoc_plugin

The helloworld example demonstrates unary RPCs using Dart gRPC libraries. You can run the sample using either TCP or Unix Domain Sockets (UDS).

TCP Setup

1. Navigate to the example/helloworld/ directory.
2. Install dependencies:

   dart pub get

3. Start the server in one terminal:

   dart bin/server.dart

4. Start the client in another terminal:

   dart bin/client.dart

UDS Setup (*nix only)

Note: UDS is only supported on *nix platforms.

1. Start the server:

   dart bin/unix_server.dart

2. Start the client:

   dart bin/unix_client.dart

# Install dependencies
dart pub get

# Run TCP server
dart bin/server.dart

# Run TCP client
dart bin/client.dart

If you modify the service or message definitions in your .proto files, you must regenerate the Dart stubs.

Prerequisites:

• protoc version 3.0.0 or higher.
• protoc_plugin (Dart plugin) version 0.7.9 or higher.

Setup Steps:

1. Install protoc for your OS from the Protocol Buffers releases page.
2. Install the Dart plugin: pub global activate protoc_plugin.
3. Ensure ~/.pub-cache/bin is in your PATH.

Regeneration Command: Use the following command to generate files into lib/src/generated: protoc --dart_out=grpc:lib/src/generated -Iprotos protos/route_guide.proto

# Install the Dart protoc plugin
$ pub global activate protoc_plugin

# Regenerate the Dart files
$ protoc --dart_out=grpc:lib/src/generated -Iprotos protos/route_guide.proto

For a complete, step-by-step guide to getting started with gRPC in Dart, refer to the official gRPC documentation.

https://grpc.io/docs/quickstart/dart

To run the grpc-web example, you need to install the webdev tool and have a gRPC-Web capable server running (such as the echo example from the grpc-web repository).

Prerequisites

1. Install webdev globally via Dart:

   dart pub global activate webdev

2. Ensure you have a gRPC-Web server available. The simplest way is using Docker Compose to run the node-server, envoy, and commonjs-client services.

To begin using gRPC in your Dart project, you can follow the official Quick Start guide to get an application running. For practical implementations, refer to the project's example directory or the official API reference.

• Quick Start: https://grpc.io/docs/languages/dart/quickstart
• Examples: https://github.com/grpc/grpc-dart/tree/master/example
• API Reference: https://grpc.io/docs/languages/dart/api