JSON-RPC2 over Websocket for Unreal Engine 4.
its appropriate for any kind of project that needs to comunicate with a json-rpc websocket server. if you by happen want to write your server in nodejs, I have a lib already.
- APIs for both blueprint and C++. one intance can be shared.
- Bidirectional, both sides can send and recieve Request and Notification
- Auto reconnect feature
- ...
#pragma once
#include "JwRPC.h"
#include "SampleCode.generated.h"
UCLASS()
class UMyConnection : public UJwRpcConnection
{
GENERATED_BODY()
UMyConnection()
{
this->RegisterNotificationCallback(TEXT("greet"), FNotifyCB::CreateUObject(this, &UMyConnection::OnNotification_Greet));
this->RegisterRequestCallback(TEXT("divide"), FRequestCB::CreateUObject(this, &UMyConnection::OnRequest_Divide));
}
void OnConnected(bool bReconnect) override
{
//send a notification to server
this->Notify(TEXT("hi"), MakeShared<FJsonValueString>(TEXT("hi. how is it going ?")));
//make the parameters and send a request to the server
auto params = MakeShared<FJsonObject>();
params->SetNumberField(TEXT("a"), 10);
params->SetNumberField(TEXT("b"), 20);
this->Request(TEXT("sum"), MakeShared<FJsonValueObject>(params), FSuccessCB::CreateLambda([](TSharedPtr<FJsonValue> result) {
//the result has arrived. it must be 20
check(result->AsNumber() == 20);
}), nullptr);
}
//this is called if server sends us 'greet' notification
void OnNotification_Greet(TSharedPtr<FJsonValue> params)
{
}
//this is called if server sends us 'divide' request
void OnRequest_Divide(TSharedPtr<FJsonValue> params, FJwRpcIncomingRequest& handle)
{
const int left = params->AsObject()->GetIntegerField("left");
const int right = params->AsObject()->GetIntegerField("right");
//send error if its divide by zero
if (right == 0)
return handle.FinishError(666, TEXT("divide by zero"));
//send the result of division
handle.FinishSuccess(MakeShared<FJsonValueNumber>(left / right));
}
};
//we create our connection and start connecting ...
UMyConnection* pConnection = UJwRpcConnection::CreateAndConnect<UMyConnection>(TEXT("ws://localhost"));
//the connection is closed if gets garbage collected. we keep a reference in the game instance
MyGameInstance->ClientConnection = pConnection;
