json_rpc_codegen #

A dart code generator that generates typed client and server code for the json_rpc_2 package.

Table of Contents #

Features #

• Code generator for the json_rpc_2 package (The official JSON-RPC 2.0 implementation for dart)
• Creates Client and Server classes, as well as Mixins
  • You can directly use the Client/Server classes for simple usecases
  • If you need to work with Peers, or if you want to have a single server/client instance that provides/consumes multiple definitions, you can creates those by using the base class and the mixins
• Supports all basic dart types and custom JSON serializables as well
  • Can handle primitive types (bool, int, ...)
  • Can handle infinitely nested containes (List, Set, Map, ...)
  • Can handle infinitely nested records
  • Can handle advanced dart types (DateTime, Uri)
  • Can handle custom types via fromJson and toJson methods
• Methods can define typed named or positional parameters
  • All types supported
  • With server-sided JSON validation
  • Default-Values are supported (Client or Server-Sided)

Installation #

As this is a builder package, you need to also install the annotations and build_runner:

dependencies:
  json_rpc_codegen: <latest>

dev_dependencies:
  build_runner: <latest>
  json_rpc_codegen_builder: <latest>

Usage #

The API usage is very basic. You create an abstract dart class that describes the interface, and the code generator will do the rest for you:

import 'package:json_rpc_codegen/json_rpc_codegen.dart';

part 'my_class.g.dart';

enum Stage { all, pre, post }

@jsonRpc
abstract class _MyClass {
  void startServerTask({
    required int id,
    required String taskName,
    bool verbose = false,
    double? scale,
  });

  @clientDefaults
  double getProgress(int id, [Stage stage = Stage.all]);
}

This will generate a bunch of code for both, the client and the server implementation. Have a look at the documentation on how to control which of these classes get generated. By default, the following will be generated:

• MyClassClientMixin: A Mixin on the ClientBase class that has all the client implementations of the interface
• MyClassServerMixin: A Mixin on the ServerBase class that has all the server implementations of the interface
• MyClassClient: A class that uses the MyClassClientMixin, ready for use
• MyClassServer: A class that uses the MyClassServerMixin, ready for use

In most cases, you will want to use MyClassClient and MyClassServer directly. However, if you want to combine multiple interfaces into one, or if you are working with Peers, you may want to use the mixins instead.

Here is a simplified example, of how the generated classes look:

class MyClassClient {
  void startServerTask({
    required int id,
    required String taskName,
    // all optional parameters are nullable, as the defaults are managed by the server
    bool? verbose,
    double? scale,
  });

  // non-void methods become futures to wait for the result
  Future<double> getProgress(
    int id, [
    // client defaults are set on the client instead
    Stage stage = Stage.all,
  ]);
}

// The server is abstract, as you need to implement the logic of the server methods
abstract class MyClassServer {
  // All server methods use FutureOr and can be synchronous or asynchronous
  @protected
  FutureOr<void> startServerTask(
    int id,
    String taskName,
    // server defaults are set by the implementation
    bool verbose,
    double? scale,
  );

  @protected
  FutureOr<double> getProgress(
    int id,
    // client defaults are required on the server side
    Stage stage,
  );
}

To use the client, simply create a new instance, just as you would with the standard json_rpc_2 client. For the server, create your own server class that extends the generated server to implement the server methods. Then you can use this class just like the json_rpc_2, but without you having to take care of any registrations.

Documentation #

The documentation is available at https://pub-web.flutter-io.cn/documentation/json_rpc_codegen/latest/. A full example can be found at https://pub-web.flutter-io.cn/packages/json_rpc_codegen_builder/example.