render annotations map for request paths and call onRequest hook if defined

_examples/golang-basics/example.ridl

@@ -92,6 +92,7 @@ service ExampleService
   # Status endpoint
   #
   # gives you current status of running application
+  @internal
   - Status() => (status: bool)
   - Version() => (version: Version)
   - GetUser(header: map<string,string>, userID: uint64) => (user: User)

helpers.go.tmpl

@@ -5,6 +5,12 @@
 // Helpers
 //
 
+type MethodCtx struct  {
+  Name string
+  Service string
+  Annotations map[string]string
+}
+
 type contextKey struct {
 	name string
 }
@@ -26,6 +32,8 @@ var (
 	ServiceNameCtxKey = &contextKey{"ServiceName"}
 
 	MethodNameCtxKey = &contextKey{"MethodName"}
+
+	methodAnnotationsCtxKey = &contextKey{"MethodAnnotations"}
 )
 
 func ServiceNameFromContext(ctx context.Context) string {
@@ -43,7 +51,19 @@ func RequestFromContext(ctx context.Context) *http.Request {
 	return r
 }
 
-{{- if $opts.server}}
+func MethodFromContext(ctx context.Context) MethodCtx {
+	name, _ := ctx.Value(MethodNameCtxKey).(string)
+	service, _ := ctx.Value(ServiceNameCtxKey).(string)
+	annotations, _ := ctx.Value(methodAnnotationsCtxKey).(map[string]string)
+
+	return MethodCtx{
+		Name: name,
+		Service: service,
+		Annotations: annotations,
+	}
+}
+
+{{ if $opts.server}}
 func ResponseWriterFromContext(ctx context.Context) http.ResponseWriter {
 	w, _ := ctx.Value(HTTPResponseWriterCtxKey).(http.ResponseWriter)
 	return w

server.go.tmpl

@@ -20,6 +20,7 @@ type WebRPCServer interface {
 type {{$serviceName}} struct {
 	{{$typePrefix}}{{$service.Name}}
 	OnError func(r *http.Request, rpcErr *WebRPCError)
+	OnRequest func(w http.ResponseWriter, r *http.Request) error
 }
 
 func New{{firstLetterToUpper $service.Name}}Server(svc {{$typePrefix}}{{.Name}}) *{{$serviceName}} {
@@ -41,6 +42,7 @@ func (s *{{$serviceName}}) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	ctx = context.WithValue(ctx, HTTPResponseWriterCtxKey, w)
 	ctx = context.WithValue(ctx, HTTPRequestCtxKey, r)
 	ctx = context.WithValue(ctx, ServiceNameCtxKey, "{{.Name}}")
+	ctx = context.WithValue(ctx, methodAnnotationsCtxKey, methodAnnotations[r.URL.Path])
 
 	var handler func(ctx context.Context, w http.ResponseWriter, r *http.Request)
 	switch r.URL.Path {
@@ -69,6 +71,17 @@ func (s *{{$serviceName}}) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 	switch contentType {
 	case "application/json":
+        if s.OnRequest != nil {
+			if err := s.OnRequest(w, r); err != nil {
+				rpcErr, ok := err.(WebRPCError)
+				if !ok {
+					rpcErr = ErrWebrpcEndpoint.WithCause(err)
+				}
+				s.sendErrorJSON(w, r, rpcErr)
+				return
+			}
+        }
+
 		handler(ctx, w, r)
 	default:
 		err := ErrWebrpcBadRequest.WithCause(fmt.Errorf("unsupported Content-Type %q (only application/json is allowed)", r.Header.Get("Content-Type")))

types.go.tmpl

@@ -29,6 +29,20 @@
 
 {{- end }}
 
+var (
+	methodAnnotations = map[string]map[string]string{
+		{{- range $_, $service := $services -}}
+			{{- range $_, $method := $service.Methods }}
+			"/rpc/{{$service.Name}}/{{$method.Name}}": {
+				{{- range $_, $annotation := $method.Annotations -}}
+					"{{$annotation.AnnotationType}}": "{{$annotation.Value}}",
+				{{- end -}}
+			},
+			{{- end -}}
+		{{ end }}
+	}
+)
+
 var WebRPCServices = map[string][]string{
 {{- range $_, $service := $services}}
 	"{{$service.Name}}": {