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 method struct  {
+	Name string
+	Service string
+	Annotations map[string]string
+}
+
 type contextKey struct {
 	name string
 }
@@ -43,7 +49,21 @@ func RequestFromContext(ctx context.Context) *http.Request {
 	return r
 }
 
-{{- if $opts.server}}
+func MethodCtx(ctx context.Context) (method, bool) {
+	req := RequestFromContext(ctx)
+	if req == nil {
+		return method{}, false
+	}
+
+	m, ok := methods[req.URL.Path]
+	if !ok {
+		return method{}, false
+	}
+
+	return m, true
+}
+
+{{ 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}}) *{{$serviceName}} {
@@ -42,6 +43,8 @@ func (s *{{$serviceName}}) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	ctx = context.WithValue(ctx, HTTPRequestCtxKey, r)
 	ctx = context.WithValue(ctx, ServiceNameCtxKey, "{{.Name}}")
 
+	r = r.WithContext(ctx)
+
 	var handler func(ctx context.Context, w http.ResponseWriter, r *http.Request)
 	switch r.URL.Path {
 	{{- range $_, $method := $service.Methods}}
@@ -69,6 +72,17 @@ func (s *{{$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 +29,24 @@
 
 {{- end }}
 
+var (
+	methods = map[string]method{
+		{{- range $_, $service := $services -}}
+			{{- range $_, $method := $service.Methods }}
+			"/rpc/{{$service.Name}}/{{$method.Name}}": {
+				Name: "{{$method.Name}}",
+				Service: "{{$service.Name}}",
+				Annotations: map[string]string{
+					{{- range $_, $annotation := $method.Annotations -}}
+					"{{$annotation.AnnotationType}}": "{{$annotation.Value}}",
+					{{- end -}}
+				},
+			},
+			{{- end -}}
+		{{ end }}
+	}
+)
+
 var WebRPCServices = map[string][]string{
 {{- range $_, $service := $services}}
 	"{{$service.Name}}": {