general_json_rpc

Description:

general json rpc

GeneralJsonRpc #
GeneralJsonRpc is a package that implements json-rpc v2.0 and its purpose is to ease invoking methods and exchange data throw network
the package is focusing on encoding and decoding json-rpc messages to and from bytes
to ease sending and receiving using any protocol
A Quick Guide #
In this guide you will create a server and client sides application that invokes methods throw
tcp sockets
lets start


First on the server side we will define 3 methods [sum, print, quit]


The sum method will get numbers list and returns their sum


The print method will get a parameter named message and print its content on the server side


The quit method will end the application by executing exit(0);




import 'dart:io';
import 'package:general_json_rpc/general_json_rpc.dart';

void main() {
server();
client();
}
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final server = await ServerSocket.bind(InternetAddress.anyIPv4, 8081);
print('[server] Server is running on port 8081');

// create MethodRunner to define the rpc methods
final runner = MethodRunner();

// now lets define the 3 methods
runner.register<int>('sum', (numbers) => numbers.reduce((a, b) => a + b));
runner.register<void>('print', (p) => print(p['message']));

runner.register('quit', (_) {
print('[server] Quit');
exit(0);
});

// now lets listen for new clients
await for (final Socket client in server) {
print('[server] new client');
client.listen(
(bytes) async {
// converts bytes into [RpcObject]
final rpcObject = RpcObject.decode(bytes);

// now lets handle all cases
final response = await RpcObject.auto(rpcObject, methodRunner: runner);

// now lets send the response to the client if it is not null
// before send we must convert it to bytes using the `encode()` method
if (response != null) client.add(response.encode());
},
);
}
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void client() async {
print('[client] connecting...');
final client = await Socket.connect(InternetAddress.loopbackIPv4, 8081);
print('[client] connected!');

// lets create controller to help send requests and responses
final controller = RpcController();

// lets use our controller to send requests and responses
controller.sendEvent.addListener(
// ! encode [rpcMessage] before send
(rpcMessage) => client.add(rpcMessage.encode()),
);

// lets listen for messages
client.listen(
(bytes) async {
// convert bytes into [RpcObject]
final rpcObject = RpcObject.decode(bytes);

// now lets handle the rpcObject
RpcObject.auto(rpcObject, controller: controller);
},
);

// now lets first request the `sum` method
// we will pass 3 numbers 1, 2, 3 in a list
// the sum will return as Future<int>
// we can handle errors by listening for [RpcError]
controller.request<int>('sum', [1, 2, 3]).then((result) {
print('[client] sum result: $result');
}).onError<RpcError>((error, _) {
print('[client] error: ${error.message}');
});

// ============================= //
// now lets call the `print` method without expecting a response
controller.notify(
'print',
{
'message': 'A message to be printed on the server side by the client',
},
);

// ============================= //
// now lets shutdown the server by calling the `quit` method after 5 seconds
// we expect no returned value
// so we will send a rpc notification
await Future.delayed(
const Duration(seconds: 5),
() => controller.notify('quit'),
);
}
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