endpoint.go

import (
	"github.com/go-kit/kit/endpoint"
	"github.com/go-kit/kit/log"
	"golang.org/x/net/context"
	// ...
)

func MakeJSONRPCEndpoint(registry RPCMethodRegistry, logger log.Logger) endpoint.Endpoint {
	return func(_ context.Context, request interface{}) (interface{}, error) {
		typedRequest := request.(JSONRPCRequest)
		response := JSONRPCResponse{
			ID:      typedRequest.ID,
			Version: typedRequest.Version,
		}

		method := JSONRPCMethod(typedRequest.Method)
		if !registry.HasMethod(method) {
			response.Error = JSONRPCError{
				Message: `Method ` + typedRequest.Method + ` doesn't exist`,
				Code:    JSONRPCErrMethodNotFound,
			}
			logger.Log(`method`, typedRequest.Method, `msg`, response.Error)
			return response, nil
		}

		logger.Log(`method`, typedRequest.Method, `params`, string(*typedRequest.Params))
		cb := registry.GetMethod(method)
		v, err := cb(typedRequest.Params)

		if err != nil {
			response.Error = JSONRPCError{
				Message: err.Error(),
				Code:    JSONRPCErrMethodNotFound,
			}
			return response, nil
		}

		response.Result = v.Result
		return response, nil

	}
}

// ..

type JSONRPCRequest struct {
	Version string           `json:"jsonrpc"`
	Method  string           `json:"method"`
	Params  *json.RawMessage `json:"params"`
	ID      *json.RawMessage `json:"id"`
}

type JSONRPCResponse struct {
	Version string           `json:"jsonrpc"`
	ID      *json.RawMessage `json:"id"`
	Result  interface{}      `json:"result,omitempty"`
	Error   JSONRPCError     `json:"error,omitempty"`
}

type JSONRPCError struct {
	Code    int         `json:"code,omitempty"`
	Message string      `json:"message,omitempty"`
	Data    interface{} `json:"data,omitempty"`
}

// ..

methodRegistry.AddMethod(
	myjsonrpc.JSONRPCMethod(`items.getAll`),
	func(r myjsonrpc.ServiceRegistry, p *json.RawMessage, l log.Logger) (myjsonrpc.ServiceResponse, error) {
		var err error
		var result interface{}
		var params = items.GetAllParams{}
	
		if err = myjsonrpc.MakeParameters(p, &params); err == nil {
			result, err = r.GetService(items.ServiceName).(items.Service).GetAll(params)
		}
	
		return myjsonrpc.ServiceResponse{
			Result: result,
		}, err
	
	})